RecoveryTests.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

// This test file has been translated from swift/test/Parse/recovery.swift

import SwiftSyntax
import XCTest

final class RecoveryTests: ParserTestCase {
  func testRecovery4() {
    assertParse(
      #"""
      func garbage() -> () {
        var a : Int
        1️⃣) this line is invalid, but we will stop at the keyword below...
        return a + "a"
      }
      """#,
      diagnostics: [
        DiagnosticSpec(
          message:
            "unexpected code ') this line is invalid, but we will stop at the keyword below...' before 'return' statement"
        )
      ]
    )
  }

  func testRecovery5() {
    assertParse(
      #"""
      func moreGarbage() -> () {
        1️⃣) this line is invalid, but we will stop at the declaration...
        func a() -> Int { return 4 }
        return a() + "a"
      }
      """#,
      diagnostics: [
        DiagnosticSpec(
          message: "unexpected code ') this line is invalid, but we will stop at the declaration...' before function"
        )
      ]
    )
  }

  func testRecovery6() {
    assertParse(
      """
      class Container<T> {
        func exists() -> Bool { return true }
      }
      """
    )
  }

  func testRecovery7() {
    assertParse(
      """
      func useContainer() -> () {
        var a : Containerℹ️<not1️⃣ 2️⃣a type [skip 3️⃣this greater: >] >4️⃣, b : Int
        b = 5 // no-warning
        a.exists()
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected '=' in variable",
          fixIts: ["insert '='"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "unexpected code 'this greater: >' in subscript"
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "expected expression after operator",
          fixIts: ["insert expression"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "unexpected code in function"
        ),
      ],
      applyFixIts: ["insert '>'", "insert expression"],
      fixedSource: """
        func useContainer() -> () {
          var a : Container<not> a type [skip this greater: >] > <#expression#>, b : Int
          b = 5 // no-warning
          a.exists()
        }
        """
    )
  }

  func testRecovery8() {
    assertParse(
      """
      @xyz class BadAttributes {
        func exists() -> Bool { return true }
      }
      """
    )
  }

  func testRecovery9() {
    assertParse(
      """
      func test(a: BadAttributes) -> () {
        _ = a.exists() // no-warning
      }
      """
    )
  }

  func testRecovery10a() {
    assertParse(
      """
      // Here is an extra random close-brace!
      1️⃣}
      //===--- Recovery for braced blocks.
      func braceStmt1() {
        { braceStmt1(); }2️⃣a
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "unexpected brace before function"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
      ],
      applyFixIts: ["insert newline"],
      fixedSource: """
        // Here is an extra random close-brace!
        }
        //===--- Recovery for braced blocks.
        func braceStmt1() {
          { braceStmt1(); }
          a
        }
        """
    )
  }

  func testRecovery10b() {
    assertParse(
      """
      // Here is an extra random close-brace!
      1️⃣}
      //===--- Recovery for braced blocks.
      func braceStmt1() {
        { braceStmt1(); }2️⃣a
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "unexpected brace before function"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
      ],
      applyFixIts: ["insert ';'"],
      fixedSource: """
        // Here is an extra random close-brace!
        }
        //===--- Recovery for braced blocks.
        func braceStmt1() {
          { braceStmt1(); }; a
        }
        """
    )
  }

  func testRecovery11() {
    assertParse(
      """
      func braceStmt2() {
        { () in braceStmt2(); }
      }
      """
    )
  }

  func testRecovery12() {
    assertParse(
      """
      func braceStmt3() {
        {
          undefinedIdentifier {}
        }
      }
      """
    )
  }

  // MARK: - Recovery for misplaced 'static'

  func testRecovery13() {
    assertParse(
      """
      static func toplevelStaticFunc() {}
      static struct StaticStruct {}
      static class StaticClass {}
      static protocol StaticProtocol {}
      static typealias StaticTypealias = Int
      class ClassWithStaticDecls {
        class var a = 42
      }
      """
    )
  }

  func testRecovery13b() {
    assertParse(
      """
      if1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected expression and body in 'if' statement",
          fixIts: ["insert expression and body"]
        )
      ],
      fixedSource: """
        if <#expression#> {
        }
        """
    )
  }

  func testRecovery14() {
    assertParse(
      """
      if 1️⃣{
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery15() {
    assertParse(
      """
      if 1️⃣
        {
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery16() {
    assertParse(
      """
      if true {
        } else if 1️⃣{
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery17() {
    // It is debatable if we should do recovery here and parse { true } as the
    // body, but the error message should be sensible.
    assertParse(
      """
      if 1️⃣{ true } {
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery18() {
    assertParse(
      """
      if 1️⃣{ true }() {
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery19() {
    // <rdar://problem/18940198>
    assertParse(
      """
      if 1️⃣{ { } }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'if' statement")
      ]
    )
  }

  func testRecovery20() {
    assertParse(
      """
      while1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected expression and code block in 'while' statement",
          fixIts: ["insert expression and code block"]
        )
      ],
      fixedSource: """
        while <#expression#> {
        }
        """
    )
  }

  func testRecovery21() {
    assertParse(
      """
      while 1️⃣{
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'while' statement")
      ]
    )
  }

  func testRecovery22() {
    assertParse(
      """
      while 1️⃣
        {
        }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'while' statement")
      ]
    )
  }

  func testRecovery23() {
    // It is debatable if we should do recovery here and parse { true } as the
    // body, but the error message should be sensible.
    assertParse(
      """
      while 1️⃣{ true } {
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'while' statement")
      ]
    )
  }

  func testRecovery24() {
    assertParse(
      """
      while 1️⃣{ true }() {
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'while' statement")
      ]
    )
  }

  func testRecovery25() {
    // <rdar://problem/18940198>
    assertParse(
      """
      while 1️⃣{ { } }
      """,
      diagnostics: [
        DiagnosticSpec(message: "missing condition in 'while' statement")
      ]
    )
  }

  func testRecovery26() {
    assertParse(
      """
      repeat {
      } while1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected condition in 'repeat' statement", fixIts: ["insert condition"])
      ],
      fixedSource: """
        repeat {
        } while <#expression#>
        """
    )
  }

  func testRecovery27() {
    assertParse(
      """
      {
        missingControllingExprInRepeatWhile();
      }
      """
    )
  }

  func testRecovery28() {
    assertParse(
      """
      repeat {
      } while { true }()
      """,
      diagnostics: [
        // TODO: Old parser expected error on line 2: missing condition in 'while' statement
        // TODO: Old parser expected error on line 2: consecutive statements on a line must be separated by ';', Fix-It replacements: 10 - 10 = ';'
        // TODO: Old parser expected warning on line 2: result of call to closure returning 'Bool' is unused
      ]
    )
  }

  func testRecovery29() {
    // https://github.com/apple/swift/issues/42787
    assertParse(
      """
      repeat {
      }1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected 'while' and condition in 'repeat' statement",
          fixIts: ["insert 'while' and condition"]
        )
      ],
      fixedSource: """
        repeat {
        } while <#expression#>
        """
    )
  }

  func testRecovery30() {
    assertParse(
      """
      for 1️⃣; {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        ),
        DiagnosticSpec(message: "unexpected ';' separator", fixIts: ["remove ';'"]),
      ],
      fixedSource: """
        for <#pattern#> in <#expression#> {
        }
        """
    )
  }

  func testRecovery31() {
    assertParse(
      """
      for 1️⃣;
        {
        }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        ),
        DiagnosticSpec(message: "unexpected ';' separator", fixIts: ["remove ';'"]),
      ],
      fixedSource: """
        for <#pattern#> in <#expression#>
          {
          }
        """
    )
  }

  func testRecovery32() {
    assertParse(
      """
      for 1️⃣; true {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        ),
        DiagnosticSpec(message: "unexpected code '; true' in 'for' statement"),
      ],
      fixedSource: """
        for <#pattern#> in <#expression#> ; true {
        }
        """
    )
  }

  func testRecovery33() {
    assertParse(
      """
      for var i 1️⃣= 0; true {
        i += 1
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected 'in' and expression in 'for' statement",
          fixIts: ["insert 'in' and expression"]
        ),
        DiagnosticSpec(message: "unexpected code '= 0; true' in 'for' statement"),
      ],
      fixedSource: """
        for var i in <#expression#> = 0; true {
          i += 1
        }
        """
    )
  }

  func testRecovery34() {
    assertParse(
      """
      for1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected pattern, 'in', expression, and body in 'for' statement",
          fixIts: ["insert pattern, 'in', expression, and body"]
        )
      ],
      fixedSource: """
        for <#pattern#> in <#expression#> {
        }
        """
    )
  }

  func testRecovery35() {
    assertParse(
      """
      for 1️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        )
      ],
      fixedSource: """
        for <#pattern#> in <#expression#> {
        }
        """
    )
  }

  func testRecovery36() {
    assertParse(
      """
      for1️⃣
      {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        )
      ],
      fixedSource: """
        for <#pattern#> in <#expression#>
        {
        }
        """
    )
  }

  func testRecovery37() {
    assertParse(
      """
      for i 1️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected 'in' and expression in 'for' statement",
          fixIts: ["insert 'in' and expression"]
        )
      ],
      fixedSource: """
        for i in <#expression#> {
        }
        """
    )
  }

  func testRecovery38() {
    assertParse(
      """
      for var i 1️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected 'in' and expression in 'for' statement",
          fixIts: ["insert 'in' and expression"]
        )
      ],
      fixedSource: """
        for var i in <#expression#> {
        }
        """
    )
  }

  func testRecovery39() {
    assertParse(
      """
      for 1️⃣in 2️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "keyword 'in' cannot be used as an identifier here",
          fixIts: ["if this name is unavoidable, use backticks to escape it"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected 'in' and expression in 'for' statement",
          fixIts: ["insert 'in' and expression"]
        ),
      ],
      fixedSource: """
        for `in` in <#expression#> {
        }
        """
    )
  }

  func testRecovery40() {
    assertParse(
      """
      for 1️⃣0..<12 {
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected pattern and 'in' in 'for' statement", fixIts: ["insert pattern and 'in'"])
      ],
      fixedSource: """
        for <#pattern#> in 0..<12 {
        }
        """
    )
  }

  func testRecovery41() {
    assertParse(
      """
      for 1️⃣for in 2️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "keyword 'for' cannot be used as an identifier here",
          fixIts: ["if this name is unavoidable, use backticks to escape it"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected Sequence expression for for-each loop",
          fixIts: ["insert expression"]
        ),
      ],
      fixedSource: """
        for `for` in <#expression#> {
        }
        """
    )
  }

  func testRecovery42() {
    assertParse(
      """
      for i in 1️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected Sequence expression for for-each loop", fixIts: ["insert expression"])
      ],
      fixedSource: """
        for i in <#expression#> {
        }
        """
    )
  }

  func testRecovery44() {
    // https://github.com/apple/swift/issues/48502
    assertParse(
      #"""
      struct User { let name: String? }

      let users = [User]()
      for user in users 1️⃣whe {
        if let name = user.name {
          let key = "\(name)"
        }
      }
      """#,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code 'whe' in 'for' statement")
      ]
    )
  }

  func testRecovery45a() {
    assertParse(
      """
      for 1️⃣
        2️⃣;
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected pattern, 'in', and expression in 'for' statement",
          fixIts: ["insert pattern, 'in', and expression"]
        ),
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected '{' in 'for' statement", fixIts: ["insert '{'"]),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "standalone ';' statements are not allowed",
          fixIts: ["remove ';'"]
        ),
      ],
      fixedSource: """
        for 
          <#pattern#> in <#expression#> {
        }
        """
    )
  }

  func testRecovery45b() {
    assertParse(
      """
      switch1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected expression and '{}' to end 'switch' statement",
          fixIts: ["insert expression and '{}'"]
        )
      ],
      fixedSource: """
        switch <#expression#> {
        }
        """
    )
  }

  func testRecovery46() {
    assertParse(
      """
      switch 1️⃣{
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected expression in 'switch' statement",
          fixIts: ["insert expression"]
        )
      ],
      fixedSource: """
        switch <#expression#> {
        }
        """
    )
  }

  func testRecovery47() {
    assertParse(
      """
      switch 1️⃣
      {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected expression in 'switch' statement",
          fixIts: ["insert expression"]
        )
      ],
      fixedSource: """
        switch <#expression#>
        {
        }
        """
    )
  }

  func testRecovery48() {
    assertParse(
      """
      switch 1️⃣{
        2️⃣case _: return
      }
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected expression in 'switch' statement")
      ]
    )
  }

  func testRecovery49() {
    assertParse(
      """
      switch 1️⃣{
        case Int: return
        case _: return
      }
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected expression in 'switch' statement")
      ]
    )
  }

  func testRecovery50() {
    assertParse(
      """
      switch 1️⃣{ 2️⃣42 } {
        3️⃣case _: return
      }
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected expression in 'switch' statement"),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "all statements inside a switch must be covered by a 'case' or 'default' label",
          fixIts: ["insert label"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "'case' can only appear inside a 'switch' statement or 'enum' declaration"
        ),
      ],
      fixedSource: """
        switch {
        case <#identifier#>: 42 } {
          case _: return
        }
        """
    )
  }

  func testRecovery51a() {
    assertParse(
      """
      switch 1️⃣{ 2️⃣42 }()3️⃣ {
        4️⃣case _: return
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected expression in 'switch' statement"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "all statements inside a switch must be covered by a 'case' or 'default' label",
          fixIts: ["insert label"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "'case' can only appear inside a 'switch' statement or 'enum' declaration"
        ),
      ],
      applyFixIts: ["insert label", "insert newline"],
      fixedSource: """
        switch {
        case <#identifier#>: 42 }()
        {
          case _: return
        }
        """
    )
  }

  func testRecovery51b() {
    assertParse(
      """
      switch 1️⃣{ 2️⃣42 }()3️⃣ {
        4️⃣case _: return
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected expression in 'switch' statement"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "all statements inside a switch must be covered by a 'case' or 'default' label",
          fixIts: ["insert label"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "'case' can only appear inside a 'switch' statement or 'enum' declaration"
        ),
      ],
      applyFixIts: ["insert label", "insert ';'"],
      fixedSource: """
        switch {
        case <#identifier#>: 42 }(); {
          case _: return
        }
        """
    )
  }

  // MARK: - Recovery for missing braces in nominal type decls.

  func testRecovery54() {
    assertParse(
      """
      struct NoBracesStruct11️⃣()
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected member block in struct", fixIts: ["insert member block"])
      ],
      fixedSource: """
        struct NoBracesStruct1 {
        }()
        """
    )
  }

  func testRecovery55() {
    assertParse(
      """
      enum NoBracesUnion11️⃣()
      class NoBracesClass12️⃣()
      protocol NoBracesProtocol13️⃣()
      extension NoBracesStruct14️⃣()
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected '{' in enum", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "1️⃣", message: "unexpected code '()' before class"),
        DiagnosticSpec(locationMarker: "2️⃣", message: "expected '{' in class", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "2️⃣", message: "unexpected code '()' before protocol"),
        DiagnosticSpec(locationMarker: "3️⃣", message: "expected '{' in protocol", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "3️⃣", message: "unexpected code '()' before extension"),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "expected member block in extension",
          fixIts: ["insert member block"]
        ),
        DiagnosticSpec(locationMarker: "4️⃣", message: "expected '}' to end protocol", fixIts: ["insert '}'"]),
        DiagnosticSpec(locationMarker: "4️⃣", message: "expected '}' to end class", fixIts: ["insert '}'"]),
        DiagnosticSpec(locationMarker: "4️⃣", message: "expected '}' to end enum", fixIts: ["insert '}'"]),
      ],
      fixedSource: """
        enum NoBracesUnion1 {()
        class NoBracesClass1 {()
        protocol NoBracesProtocol1 {()
        extension NoBracesStruct1 {
        }
        }
        }
        }()
        """
    )
  }

  func testRecovery56() {
    assertParse(
      """
      struct NoBracesStruct2 1️⃣
      enum NoBracesUnion2 2️⃣
      class NoBracesClass2 3️⃣
      protocol NoBracesProtocol2 4️⃣
      extension NoBracesStruct25️⃣
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected '{' in struct", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "2️⃣", message: "expected '{' in enum", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "3️⃣", message: "expected '{' in class", fixIts: ["insert '{'"]),
        DiagnosticSpec(locationMarker: "4️⃣", message: "expected '{' in protocol", fixIts: ["insert '{'"]),
        DiagnosticSpec(
          locationMarker: "5️⃣",
          message: "expected member block in extension",
          fixIts: ["insert member block"]
        ),
        DiagnosticSpec(locationMarker: "5️⃣", message: "expected '}' to end protocol", fixIts: ["insert '}'"]),
        DiagnosticSpec(locationMarker: "5️⃣", message: "expected '}' to end class", fixIts: ["insert '}'"]),
        DiagnosticSpec(locationMarker: "5️⃣", message: "expected '}' to end enum", fixIts: ["insert '}'"]),
        DiagnosticSpec(locationMarker: "5️⃣", message: "expected '}' to end struct", fixIts: ["insert '}'"]),
      ],
      fixedSource: """
        struct NoBracesStruct2 {
        enum NoBracesUnion2 {
        class NoBracesClass2 {
        protocol NoBracesProtocol2 {
        extension NoBracesStruct2 {
        }
        }
        }
        }
        }
        """
    )
  }

  // MARK: - Recovery for multiple identifiers in decls

  func testRecovery58() {
    assertParse(
      """
      protocol Multi 1️⃣ident {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "found an unexpected second identifier in protocol; is there an accidental break?",
          highlight: "ident",
          fixIts: ["join the identifiers together", "join the identifiers together with camel-case"]
        )
      ],
      fixItsApplications: [
        .optIn(
          applyFixIts: ["join the identifiers together"],
          fixedSource: "protocol Multiident {}"
        ),
        .optIn(
          applyFixIts: ["join the identifiers together with camel-case"],
          fixedSource: "protocol MultiIdent {}"
        ),
      ]
    )
  }

  func testRecovery60() {
    assertParse(
      """
      class CCC 1️⃣CCC<T> {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "found an unexpected second identifier in class; is there an accidental break?",
          highlight: "CCC<T>",
          fixIts: ["join the identifiers together"]
        )
      ],
      fixedSource: """
        class CCCCCC<T> {}
        """
    )
  }

  func testRecovery62a() {
    assertParse(
      """
      enum EE 1️⃣EE<T> where T : Multi {
        case a2️⃣ 3️⃣a
        case b
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "found an unexpected second identifier in enum; is there an accidental break?",
          fixIts: ["join the identifiers together"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "consecutive declarations on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(locationMarker: "3️⃣", message: "unexpected code 'a' before enum case"),
      ],
      applyFixIts: ["join the identifiers together", "insert newline"],
      fixedSource: """
        enum EEEE<T> where T : Multi {
          case a
          a
          case b
        }
        """
    )
  }

  func testRecovery62b() {
    assertParse(
      """
      enum EE 1️⃣EE<T> where T : Multi {
        case a2️⃣ 3️⃣a
        case b
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "found an unexpected second identifier in enum; is there an accidental break?",
          fixIts: ["join the identifiers together"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "consecutive declarations on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(locationMarker: "3️⃣", message: "unexpected code 'a' before enum case"),
      ],
      applyFixIts: ["join the identifiers together", "insert ';'"],
      fixedSource: """
        enum EEEE<T> where T : Multi {
          case a;a
          case b
        }
        """
    )
  }

  func testRecovery63() {
    assertParse(
      #"""
      struct SS 1️⃣SS : Multi {
        private var a 2️⃣b : Int = ""
        func f() {
          var c3️⃣ d = 5
          let _ = 0
        }
      }
      """#,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "found an unexpected second identifier in struct; is there an accidental break?",
          fixIts: ["join the identifiers together"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "found an unexpected second identifier in pattern; is there an accidental break?",
          fixIts: ["join the identifiers together", "join the identifiers together with camel-case"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "expected ':' in type annotation",
          fixIts: ["insert ':'"]
        ),
      ],
      fixedSource: #"""
        struct SSSS : Multi {
          private var ab : Int = ""
          func f() {
            var c: d = 5
            let _ = 0
          }
        }
        """#
    )
  }

  func testRecovery64a() {
    assertParse(
      """
      let (efg1️⃣ hij, foobar) = (5, 6)
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected ',' in tuple pattern", fixIts: ["insert ','"])
      ],
      fixedSource: """
        let (efg, hij, foobar) = (5, 6)
        """
    )
  }

  func testRecovery64b() {
    assertParse(
      """
      let (efg1️⃣ Hij, foobar) = (5, 6)
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected ':' in tuple pattern", fixIts: ["insert ':'"])
      ],
      fixedSource: """
        let (efg: Hij, foobar) = (5, 6)
        """
    )
  }

  func testRecovery64c() {
    assertParse(
      """
      private var a 1️⃣b : Int = ""
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "found an unexpected second identifier in pattern; is there an accidental break?",
          fixIts: ["join the identifiers together", "join the identifiers together with camel-case"]
        )
      ],
      fixedSource: """
        private var ab : Int = ""
        """
    )
  }

  func testRecovery65() {
    assertParse(
      """
      _ = foobar // OK.
      """
    )
  }

  // MARK: - Recovery for parse errors in types.

  func testRecovery67() {
    assertParse(
      """
      struct ErrorTypeInVarDecl1 {
        var v1 : 1️⃣
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected type in type annotation", fixIts: ["insert type"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl1 {
          var v1 : <#type#>
        }
        """
    )
  }

  func testRecovery68() {
    assertParse(
      """
      struct ErrorTypeInVarDecl2 {
        var v1 : Int.1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected name in member type", fixIts: ["insert name"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl2 {
          var v1 : Int.<#identifier#>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery69() {
    assertParse(
      """
      struct ErrorTypeInVarDecl3 {
        var v1 : Intℹ️< 1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl3 {
          var v1 : Int< >
          var v2 : Int
        }
        """
    )
  }

  func testRecovery70() {
    assertParse(
      """
      struct ErrorTypeInVarDecl4 {
        var v1 : Intℹ️<1️⃣,
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl4 {
          var v1 : Int< >,
          var v2 : Int
        }
        """
    )
  }

  func testRecovery71() {
    assertParse(
      """
      struct ErrorTypeInVarDecl5 {
        var v1 : Intℹ️<Int1️⃣ 
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl5 {
          var v1 : Int<Int>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery72() {
    assertParse(
      """
      struct ErrorTypeInVarDecl6 {
        var v1 : Intℹ️<Int,
                     Int1️⃣ 
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [
            NoteSpec(message: "to match this opening '<'")
          ],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl6 {
          var v1 : Int<Int,
                       Int>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery73() {
    assertParse(
      """
      struct ErrorTypeInVarDecl7 {
        var v1 : Intℹ️<Int, 1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected type in generic argument",
          fixIts: ["insert type"]
        ),
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl7 {
          var v1 : Int<Int, <#type#>>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery83() {
    assertParse(
      """
      struct ErrorTypeInVarDecl12 {
        var v1 : FooProtocol & 1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected type in type composition", fixIts: ["insert type"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl12 {
          var v1 : FooProtocol & <#type#>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery84() {
    assertParse(
      """
      struct ErrorTypeInVarDecl13 {
        var v1 : 1️⃣& FooProtocol
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected type in type composition", fixIts: ["insert type"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl13 {
          var v1 : <#type#> & FooProtocol
          var v2 : Int
        }
        """
    )
  }

  func testRecovery85() {
    assertParse(
      """
      struct ErrorTypeInVarDecl16 {
        var v1 : FooProtocol & 1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected type in type composition", fixIts: ["insert type"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDecl16 {
          var v1 : FooProtocol & <#type#>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery86() {
    assertParse(
      """
      func ErrorTypeInPattern4(_: FooProtocol & 1️⃣) { }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected type in type composition", fixIts: ["insert type"])
      ],
      fixedSource: """
        func ErrorTypeInPattern4(_: FooProtocol & <#type#>) { }
        """
    )
  }

  func testRecovery87() {
    assertParse(
      """
      struct ErrorGenericParameterList1ℹ️<1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          message: "expected member block in struct",
          fixIts: ["insert member block"]
        ),
      ],
      fixedSource: """
        struct ErrorGenericParameterList1< > {
        }
        """
    )
  }

  func testRecovery87b() {
    assertParse(
      """
      struct ErrorGenericParameterList1ℹ️<each1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected name in generic parameter",
          fixIts: ["insert name"]
        ),
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          message: "expected member block in struct",
          fixIts: ["insert member block"]
        ),
      ],
      fixedSource: """
        struct ErrorGenericParameterList1<each <#identifier#>> {
        }
        """
    )
  }

  func testRecovery88() {
    assertParse(
      """
      struct ErrorGenericParameterList2ℹ️<T1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          message: "expected member block in struct",
          fixIts: ["insert member block"]
        ),
      ],
      fixedSource: """
        struct ErrorGenericParameterList2<T> {
        }
        """
    )
  }

  func testRecovery89() {
    assertParse(
      """
      struct ErrorGenericParameterList3ℹ️<T,1️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected generic parameter in generic parameter clause",
          fixIts: ["insert generic parameter"]
        ),
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          message: "expected member block in struct",
          fixIts: ["insert member block"]
        ),
      ],
      fixedSource: """
        struct ErrorGenericParameterList3<T, <#identifier#>> {
        }
        """
    )
  }

  func testRecovery90() {
    // Note: Don't move braces to a different line here.
    assertParse(
      """
      struct ErrorGenericParameterList4ℹ️<1️⃣
      {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorGenericParameterList4< >
        {
        }
        """
    )
  }

  func testRecovery91() {
    // Note: Don't move braces to a different line here.
    assertParse(
      """
      struct ErrorGenericParameterList5ℹ️<T1️⃣ 
      {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        )
      ],
      fixedSource: """
        struct ErrorGenericParameterList5<T>
        {
        }
        """
    )
  }

  func testRecovery92() {
    // Note: Don't move braces to a different line here.
    assertParse(
      """
      struct ErrorGenericParameterList6ℹ️<T, 1️⃣
      {
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected generic parameter in generic parameter clause",
          fixIts: ["insert generic parameter"]
        ),
        DiagnosticSpec(
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
      ],
      fixedSource: """
        struct ErrorGenericParameterList6<T, <#identifier#>>
        {
        }
        """
    )
  }

  func testRecovery93() {
    assertParse(
      """
      struct ErrorTypeInVarDeclFunctionType1 {
        var v1 : () -> 1️⃣
        var v2 : Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected return type in function type", fixIts: ["insert return type"])
      ],
      fixedSource: """
        struct ErrorTypeInVarDeclFunctionType1 {
          var v1 : () -> <#type#>
          var v2 : Int
        }
        """
    )
  }

  func testRecovery98() {
    let testCases: [UInt: (testCase: String, fixedSource: String)] = [
      #line: ("let a1: Swift.Int1️⃣]", "let a1: [Swift.Int]"),
      #line: ("let a3: Set<Int>1️⃣]", "let a3: [Set<Int>]"),
      #line: ("let a4: Int1️⃣]?", "let a4: [Int]?"),
      #line: ("let a5: Int?1️⃣]", "let a5: [Int?]"),
      #line: ("let a6: [Int]1️⃣]", "let a6: [[Int]]"),
      #line: ("let a7: [String: Int]1️⃣]", "let a7: [[String: Int]]"),
      #line: ("func foo() -> Int1️⃣]??", "func foo() -> [Int]??"),
    ]

    for (line, testCase) in testCases {
      assertParse(
        testCase.testCase,
        diagnostics: [
          DiagnosticSpec(
            message: "unexpected ']' in type; did you mean to write an array type?",
            fixIts: ["insert '['"],
            line: line
          )
        ],
        fixedSource: testCase.fixedSource,
        line: line
      )
    }

    assertParse(
      """
      let a8: Int
      1️⃣]
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "extraneous code ']' at top level"
        )
      ]
    )
  }

  func testRecovery98b() {
    assertParse(
      """
      let a2: Setℹ️<Int1️⃣]>
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '>' to end generic argument clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(message: "extraneous code ']>' at top level"),
      ],
      fixedSource: """
        let a2: Set<Int>]>
        """
    )
  }

  func testRecovery99() {
    assertParse(
      """
      struct ErrorTypeInVarDeclDictionaryType {
        let a1: String1️⃣:
        let a2: 2️⃣String: Int]
        let a3: 3️⃣String: [Int]4️⃣
        let a4: 5️⃣String: Int6️⃣
        let a5: 7️⃣String: Int]??
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "consecutive declarations on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "unexpected code ':' before variable"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected '[' to start dictionary type",
          fixIts: ["insert '['"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "expected '[' to start dictionary type",
          fixIts: ["insert '['"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "expected ']' to end dictionary type",
          fixIts: ["insert ']'"]
        ),
        DiagnosticSpec(
          locationMarker: "5️⃣",
          message: "expected '[' to start dictionary type",
          fixIts: ["insert '['"]
        ),
        DiagnosticSpec(
          locationMarker: "6️⃣",
          message: "expected ']' to end dictionary type",
          fixIts: ["insert ']'"]
        ),
        DiagnosticSpec(
          locationMarker: "7️⃣",
          message: "expected '[' to start dictionary type",
          fixIts: ["insert '['"]
        ),
      ],
      fixedSource: """
        struct ErrorTypeInVarDeclDictionaryType {
          let a1: String
          :
          let a2: [String: Int]
          let a3: [String: [Int]]
          let a4: [String: Int]
          let a5: [String: Int]??
        }
        """
    )

    assertParse(
      """
      let a6: [Int: String]
      1️⃣]
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "extraneous code ']' at top level"
        )
      ]
    )
  }

  func testRecovery100() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType1 {
        func foo() -> Int1️⃣[ {
          return [0]
        }
        func bar() -> Int2️⃣] {
          return [0]
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "unexpected code '[' in function"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "unexpected ']' in type; did you mean to write an array type?",
          fixIts: ["insert '['"]
        ),
      ],
      fixedSource: """
        struct ErrorInFunctionSignatureResultArrayType1 {
          func foo() -> Int[ {
            return [0]
          }
          func bar() -> [Int] {
            return [0]
          }
        }
        """
    )
  }

  func testRecovery101() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType2 {
        func foo() -> Int1️⃣[0 {
          return [0]
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '[0' in function")
      ]
    )
  }

  func testRecovery102() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType3 {
        func foo() -> Int1️⃣[0] {
          return [0]
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '[0]' in function")
      ]
    )
  }

  func testRecovery103() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType4 {
        func foo() -> Int1️⃣[0_1] {
          return [0]
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '[0_1]' in function")
      ]
    )
  }

  func testRecovery104() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType5 {
        func foo() -> Int1️⃣[0b1] {
          return [0]
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '[0b1]' in function")
      ]
    )
  }

  func testRecovery105() {
    assertParse(
      """
      struct ErrorInFunctionSignatureResultArrayType11 {
        func foo() -> Int1️⃣[(a){a++}] {
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '[(a){a++}]' in function")
      ]
    )
  }

  // Recovery for missing initial value in var decls.

  func testRecovery107() {
    assertParse(
      """
      struct MissingInitializer1 {
        var v1 : Int = 1️⃣
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected expression in variable", fixIts: ["insert expression"])
      ],
      fixedSource: """
        struct MissingInitializer1 {
          var v1 : Int = <#expression#>
        }
        """
    )
  }

  // MARK: - Recovery for expr-postfix.

  func testRecovery109() {
    assertParse(
      """
      func exprPostfix1(x : Int) {
        x.1️⃣
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected name in member access", fixIts: ["insert name"])
      ],
      fixedSource: """
        func exprPostfix1(x : Int) {
          x.<#identifier#>
        }
        """
    )
  }

  func testRecovery110() {
    assertParse(
      """
      func exprPostfix2() {
        _ = 1️⃣.42
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "'.42' is not a valid floating point literal; it must be written '0.42'",
          fixIts: ["insert '0'"]
        )
      ],
      fixedSource: """
        func exprPostfix2() {
          _ = 0.42
        }
        """
    )
  }

  func testRecovery111() {
    assertParse(
      """
      //===---
      """
    )
  }
  // MARK: - Recovery for expr-super.

  func testRecovery112() {
    assertParse(
      """
      class Base {}
      """
    )
  }

  func testRecovery113() {
    assertParse(
      """
      class ExprSuper1 {
        init() {
          super
        }
      }
      """
    )
  }

  func testRecovery114() {
    assertParse(
      """
      class ExprSuper2 {
        init() {
          super.1️⃣
        }
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected name in member access", fixIts: ["insert name"])
      ],
      fixedSource: """
        class ExprSuper2 {
          init() {
            super.<#identifier#>
          }
        }
        """
    )
  }

  func testRecovery115() {
    assertParse(
      """
      //===--- Recovery for braces inside a nominal decl.
      """
    )
  }

  func testRecovery116() {
    assertParse(
      """
      struct BracesInsideNominalDecl1 {
        1️⃣{
          aaa
        }
        typealias A = Int
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code before typealias declaration")
      ]
    )
  }

  func testRecovery117() {
    assertParse(
      """
      func use_BracesInsideNominalDecl1() {
        // Ensure that the typealias decl is not skipped.
        var _ : BracesInsideNominalDecl1.A // no-error
      }
      """
    )
  }

  func testRecovery118() {
    // https://github.com/apple/swift/issues/43383
    assertParse(
      #"""
      class С_43383 {
          1️⃣print(2️⃣"No one else was in the room where it happened")
      }
      """#,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected 'func' in function", fixIts: ["insert 'func'"]),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: #"unexpected code '"No one else was in the room where it happened"' in parameter clause"#
        ),
      ],
      fixedSource: #"""
        class С_43383 {
            func print("No one else was in the room where it happened")
        }
        """#
    )
  }

  func testRecovery119() {
    assertParse(
      #"""
      extension С_43383 {
          1️⃣print(2️⃣"The room where it happened, the room where it happened")
      }
      """#,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected 'func' in function", fixIts: ["insert 'func'"]),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: #"unexpected code '"The room where it happened, the room where it happened"' in parameter clause"#
        ),
      ],
      fixedSource: #"""
        extension С_43383 {
            func print("The room where it happened, the room where it happened")
        }
        """#
    )
  }

  // MARK: - Recovery for wrong decl introducer keyword.

  func testRecovery121() {
    assertParse(
      """
      class WrongDeclIntroducerKeyword1 {
        1️⃣notAKeyword() {}
        func foo() {}
        class func bar() {}
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected 'func' in function", fixIts: ["insert 'func'"])
      ],
      fixedSource: """
        class WrongDeclIntroducerKeyword1 {
          func notAKeyword() {}
          func foo() {}
          class func bar() {}
        }
        """
    )

    assertParse(
      """
      class WrongDeclIntroducerKeyword1 {
        1️⃣notAKeyword() {}
        var x: Int
      }
      """,
      diagnostics: [DiagnosticSpec(message: "expected 'func' in function", fixIts: ["insert 'func'"])],
      fixedSource: """
        class WrongDeclIntroducerKeyword1 {
          func notAKeyword() {}
          var x: Int
        }
        """
    )
  }

  // MARK: - Recovery for wrong inheritance clause.

  func testRecovery123() {
    assertParse(
      """
      class Base2<T> {
      }
      """
    )
  }

  func testRecovery124() {
    assertParse(
      """
      class SubModule {
          class Base1 {}
          class Base2<T> {}
      }
      """
    )
  }

  func testRecovery125() {
    assertParse(
      """
      class WrongInheritanceClause11️⃣(Int) {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' and ')' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause1: Int {}
        """
    )
  }

  func testRecovery126() {
    assertParse(
      """
      class WrongInheritanceClause21️⃣(Base2<Int>) {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' and ')' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause2: Base2<Int>{}
        """
    )
  }

  func testRecovery127() {
    assertParse(
      """
      class WrongInheritanceClause3<T>1️⃣(SubModule.Base1) where T:AnyObject {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' and ')' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause3<T>: SubModule.Base1 where T:AnyObject {}
        """
    )
  }

  func testRecovery128() {
    assertParse(
      """
      class WrongInheritanceClause41️⃣(SubModule.Base2<Int>) {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' and ')' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause4: SubModule.Base2<Int>{}
        """
    )
  }

  func testRecovery129() {
    assertParse(
      """
      class WrongInheritanceClause5<T>1️⃣(SubModule.Base2<Int>) where T:AnyObject {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' and ')' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause5<T>: SubModule.Base2<Int>where T:AnyObject {}
        """
    )
  }

  func testRecovery130() {
    assertParse(
      """
      class WrongInheritanceClause61️⃣(Int {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause6: Int {}
        """
    )
  }

  func testRecovery131() {
    assertParse(
      """
      class WrongInheritanceClause7<T>1️⃣(Int where T:AnyObject {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ':' to begin inheritance clause",
          fixIts: ["replace '(' with ':'"]
        )
      ],
      fixedSource: """
        class WrongInheritanceClause7<T>: Int where T:AnyObject {}
        """
    )
  }

  func testRecovery132() {
    // <rdar://problem/18502220> [swift-crashes 078] parser crash on invalid cast in sequence expr
    assertParse(
      """
      Base=1 as Base=1
      """
    )
  }

  func testRecovery133() {
    // <rdar://problem/18634543> Parser hangs at swift::Parser::parseType
    assertParse(
      #"""
      public enum TestA {
        public static func convertFromExtenndition(
          s1️⃣._core.count != 0, "Can't form a Character from an empty String")
      }
      """#,
      diagnostics: [
        DiagnosticSpec(message: "expected ':' and type in parameter", fixIts: ["insert ':' and type"]),
        DiagnosticSpec(
          message:
            #"unexpected code '._core.count != 0, "Can't form a Character from an empty String"' in parameter clause"#
        ),
      ],
      fixedSource: #"""
        public enum TestA {
          public static func convertFromExtenndition(
            s: <#type#>._core.count != 0, "Can't form a Character from an empty String")
        }
        """#
    )
  }

  func testRecovery134() {
    assertParse(
      #"""
      public enum TestB {
        public static func convertFromExtenndition(
          s1️⃣._core.count ?= 0, "Can't form a Character from an empty String")
      }
      """#,
      diagnostics: [
        DiagnosticSpec(message: "expected ':' and type in parameter", fixIts: ["insert ':' and type"]),
        DiagnosticSpec(
          message:
            #"unexpected code '._core.count ?= 0, "Can't form a Character from an empty String"' in parameter clause"#
        ),
      ],
      fixedSource: #"""
        public enum TestB {
          public static func convertFromExtenndition(
            s: <#type#>._core.count ?= 0, "Can't form a Character from an empty String")
        }
        """#
    )
  }

  func testRecovery136() {
    // <rdar://problem/18634543> Infinite loop and unbounded memory consumption in parser
    assertParse(
      """
      func foo1(bar1️⃣!=baz) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected ':' and type in parameter", fixIts: ["insert ':' and type"]),
        DiagnosticSpec(message: "unexpected code '!=baz' in parameter clause"),
      ],
      fixedSource: """
        func foo1(bar: <#type#>!=baz) {}
        """
    )
  }

  func testRecovery137() {
    assertParse(
      """
      func foo2(bar1️⃣! = baz) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected ':' and type in parameter", fixIts: ["insert ':' and type"]),
        DiagnosticSpec(message: "unexpected code '! = baz' in parameter clause"),
      ],
      fixedSource: """
        func foo2(bar: <#type#>! = baz) {}
        """
    )
  }

  func testRecovery138() {
    // rdar://19605567
    assertParse(
      """
      switch esp {
      case let (jeb):
        class Ceacℹ️<1️⃣}2️⃣> {}
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected '{' in class",
          fixIts: ["insert '{'"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "unexpected code '> {}' in 'switch' statement"
        ),
      ],
      fixedSource: """
        switch esp {
        case let (jeb):
          class Ceac< > {}> {}
        }
        """
    )
  }

  func testRecovery141() {
    // rdar://19605164
    assertParse(
      """
      #if true
      struct Foo19605164 {
      func a1️⃣(s: S2️⃣3️⃣[{{g4️⃣) -> Int {}
      }}}
      #endif
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected ')' to end parameter clause",
          notes: [NoteSpec(locationMarker: "1️⃣", message: "to match this opening '('")],
          fixIts: ["insert ')'"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "unexpected code '[' in function"
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "unexpected code ') -> Int {}' in closure"
        ),
      ],
      fixedSource: """
        #if true
        struct Foo19605164 {
        func a(s: S) [{{g) -> Int {}
        }}}
        #endif
        """
    )
  }

  func testRecovery143() {
    // rdar://19605567
    assertParse(
      """
      func F() { init1️⃣<2️⃣(3️⃣ } 4️⃣)}
      struct InitializerWithName {
        init 5️⃣x() {}
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected '>' to end generic parameter clause",
          notes: [NoteSpec(locationMarker: "1️⃣", message: "to match this opening '<'")],
          fixIts: ["insert '>'"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "expected ')' to end parameter clause",
          notes: [NoteSpec(locationMarker: "2️⃣", message: "to match this opening '('")],
          fixIts: ["insert ')'"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "unexpected code ')}' before struct"
        ),
        DiagnosticSpec(
          locationMarker: "5️⃣",
          message: "initializers cannot have a name",
          fixIts: ["remove 'x'"]
        ),
      ],
      fixedSource: """
        func F() { init< >() } )}
        struct InitializerWithName {
          init() {}
        }
        """
    )
  }

  func testRecovery144() {
    assertParse(
      """
      init 1️⃣a(b: Int) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "initializers cannot have a name", fixIts: ["remove 'a'"])
      ],
      fixedSource: """
        init(b: Int) {}
        """
    )
  }

  func testRecovery145() {
    assertParse(
      """
      init? 1️⃣c(_ d: Int) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "initializers cannot have a name", fixIts: ["remove 'c'"])
      ],
      fixedSource: """
        init?(_ d: Int) {}
        """
    )
  }

  func testRecovery146() {
    assertParse(
      """
      init 1️⃣e<T>(f: T) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "initializers cannot have a name", fixIts: ["remove 'e<T>'"])
      ],
      fixedSource: """
        init(f: T) {}
        """
    )
  }

  func testRecovery147() {
    assertParse(
      """
      init? 1️⃣g<T>(_: T) {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "initializers cannot have a name", fixIts: ["remove 'g<T>'"])
      ],
      fixedSource: """
        init?(_: T) {}
        """
    )
  }

  func testRecovery148() {
    assertParse(
      """
      init1️⃣ c d: Int2️⃣ {}
      """,
      diagnostics: [
        DiagnosticSpec(locationMarker: "1️⃣", message: "expected '(' to start parameter clause", fixIts: ["insert '('"]),
        DiagnosticSpec(locationMarker: "2️⃣", message: "expected ')' to end parameter clause", fixIts: ["insert ')'"]),
      ],
      fixedSource: """
        init(c d: Int) {}
        """
    )
  }

  func testRecovery150() {
    assertParse(
      """
      let n 1️⃣== C { get {}
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "extraneous code at top level")
      ]
    )
  }

  func testRecovery151() {
    // <rdar://problem/20489838> QoI: Nonsensical error and fixit if "let" is missing between 'if let ... where' clauses
    assertParse(
      """
      if let y = x 1️⃣where y == 0, let z = x {
        _ = y
        _ = z
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ',' joining parts of a multi-clause condition",
          fixIts: ["replace 'where' with ','"]
        )
      ],
      fixedSource: """
        if let y = x, y == 0, let z = x {
          _ = y
          _ = z
        }
        """

    )
  }

  func testRecovery152() {
    assertParse(
      """
      if var y = x, y == 0, var z = x {
        z = y; y = z
      }
      """
    )
  }

  func testRecovery153() {
    assertParse(
      """
      if var y = x, 1️⃣z = x {
        z = y; y = z
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "expected 'var' in optional binding", fixIts: ["insert 'var'"])
      ],
      fixedSource: """
        if var y = x, var z = x {
          z = y; y = z
        }
        """
    )
  }

  func testRecovery154() {
    assertParse(
      #"""
      // <rdar://problem/20883210> QoI: Following a "let" condition with boolean condition spouts nonsensical errors
      guard let x: Int? = 1, x == 1 else {  }
      """#
    )
  }

  func testRecovery156() {
    assertParse(
      """
      // rdar://20866942
      func testRefutableLet() {
        var e : Int?
        let x1️⃣? = e
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '? = e' in function")
      ]
    )
  }

  func testRecovery157() {
    // <rdar://problem/19833424> QoI: Bad error message when using Objective-C literals (@"Hello")
    assertParse(
      #"""
      let myString = 1️⃣@"foo"
      """#,
      diagnostics: [
        DiagnosticSpec(
          message: "string literals in Swift are not preceded by an '@' sign",
          fixIts: ["remove '@'"]
        )
      ],
      fixedSource: """
        let myString = "foo"
        """
    )
  }

  func testRecovery158() {
    // <rdar://problem/16990885> support curly quotes for string literals
    assertParse(
      """
      let curlyQuotes1 = 1️⃣“hello world!”
      """,
      diagnostics: [
        DiagnosticSpec(
          message: #"unicode curly quote found; use '"' instead"#,
          fixIts: [#"replace curly quotes with '"'"#]
        )
      ],
      fixedSource: """
        let curlyQuotes1 = "hello world!"
        """
    )
  }

  func testRecovery159() {
    assertParse(
      #"""
      let curlyQuotes2 = 1️⃣“hello world!"
      """#,
      diagnostics: [
        DiagnosticSpec(
          message: #"unicode curly quote found; use '"' instead"#,
          fixIts: [#"replace curly quotes with '"'"#]
        )
      ],
      fixedSource: #"""
        let curlyQuotes2 = "hello world!"
        """#
    )
  }

  func testRecovery160() {
    // <rdar://problem/21196171> compiler should recover better from "unicode Specials" characters
    assertParse(
      #"""
      let 1️⃣tryx  = 123
      """#,
      diagnostics: [
        DiagnosticSpec(message: "invalid character in source file")
      ]
    )
  }

  func testRecovery161() {
    assertParse(
      """
      // <rdar://problem/21369926> Malformed Swift Enums crash playground service
      enum Rank: Int {
        case Ace = 1
        case Two = 2.1
      }
      """
    )
  }

  func testRecovery162() {
    assertParse(
      """
      // rdar://22240342 - Crash in diagRecursivePropertyAccess
      class r22240342 {
        lazy var xx: Int = {
          foo {
            let issueView = 42
            issueView.delegate = 12
          }
          return 42
          }()
      }
      """
    )
  }

  func testRecovery163() {
    // <rdar://problem/22387625> QoI: Common errors: 'let x= 5' and 'let x =5' could use Fix-its
    assertParse(
      """
      func r22387625() {
        let _1️⃣= 5
        let _ =2️⃣5
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "'=' must have consistent whitespace on both sides",
          fixIts: ["insert whitespace"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "'=' must have consistent whitespace on both sides",
          fixIts: ["insert whitespace"]
        ),
      ],
      fixedSource: """
        func r22387625() {
          let _ = 5
          let _ = 5
        }
        """
    )
  }

  func testRecovery164() {
    // https://github.com/apple/swift/issues/45723
    assertParse(
      """
      do {
        let _: Int1️⃣= 5
        let _: Array<Int>2️⃣= []
      }
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "'=' must have consistent whitespace on both sides",
          fixIts: ["insert whitespace"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "'=' must have consistent whitespace on both sides",
          fixIts: ["insert whitespace"]
        ),
      ],
      fixedSource: """
        do {
          let _: Int = 5
          let _: Array<Int> = []
        }
        """
    )
  }

  func testRecovery165() {
    assertParse(
      """
      // <rdar://problem/23086402> Swift compiler crash in CSDiag
      protocol A23086402 {
        var b: B23086402 { get }
      }
      """
    )
  }

  func testRecovery166() {
    assertParse(
      """
      protocol B23086402 {
        var c: [String] { get }
      }
      """
    )
  }

  func testRecovery167() {
    assertParse(
      #"""
      func test23086402(a: A23086402) {
        print(a.b.c + "") // should not crash but: expected-error {{}}
      }
      """#
    )
  }

  func testRecovery168() {
    assertParse(
      #"""
      // <rdar://problem/23550816> QoI: Poor diagnostic in argument list of "print" (varargs related)
      // The situation has changed. String now conforms to the RangeReplaceableCollection protocol
      // and `ss + s` becomes ambiguous. Disambiguation is provided with the unavailable overload
      // in order to produce a meaningful diagnostics. (Related: <rdar://problem/31763930>)
      func test23550816(ss: [String], s: String) {
        print(ss + s)
      }
      """#
    )
  }

  func testRecovery169() {
    assertParse(
      """
      // <rdar://problem/23719432> [practicalswift] Compiler crashes on &(Int:_)
      func test23719432() {
        var x = 42
          &(Int:x)
      }
      """,
      substructure: InOutExprSyntax(
        ampersand: .prefixAmpersandToken(),
        expression: ExprSyntax(
          TupleExprSyntax(
            leftParen: .leftParenToken(),
            elements: LabeledExprListSyntax([
              LabeledExprSyntax(
                label: .identifier("Int"),
                colon: .colonToken(),
                expression: ExprSyntax(DeclReferenceExprSyntax(baseName: .identifier("x")))
              )
            ]),
            rightParen: .rightParenToken()
          )
        )
      )

    )
  }

  func testRecovery170a() {
    // <rdar://problem/19911096> QoI: terrible recovery when using '·' for an operator
    assertParse(
      """
      infix operator 1️⃣· 2️⃣{
        associativity none precedence3️⃣ 150
      4️⃣}
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "'·' is considered an identifier and must not appear within an operator name"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "operator should not be declared with body",
          fixIts: ["remove operator body"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "extraneous brace at top level"
        ),
      ],
      applyFixIts: ["remove operator body", "insert newline"],
      fixedSource: """
        infix operator · precedence
          150
        }
        """
    )
  }

  func testRecovery170b() {
    // <rdar://problem/19911096> QoI: terrible recovery when using '·' for an operator
    assertParse(
      """
      infix operator 1️⃣· 2️⃣{
        associativity none precedence3️⃣ 150
      4️⃣}
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "'·' is considered an identifier and must not appear within an operator name"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "operator should not be declared with body",
          fixIts: ["remove operator body"]
        ),
        DiagnosticSpec(
          locationMarker: "3️⃣",
          message: "consecutive statements on a line must be separated by newline or ';'",
          fixIts: ["insert newline", "insert ';'"]
        ),
        DiagnosticSpec(
          locationMarker: "4️⃣",
          message: "extraneous brace at top level"
        ),
      ],
      applyFixIts: ["remove operator body", "insert ';'"],
      fixedSource: """
        infix operator · precedence; 150
        }
        """
    )
  }

  func testRecovery171() {
    assertParse(
      """
      infix operator -1️⃣@-class Recover1 {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "'@-class' is not allowed in operator names", fixIts: ["remove '@-class'"])
      ],
      fixedSource: """
        infix operator - Recover1 {}
        """
    )
  }

  func testRecovery172() {
    assertParse(
      """
      prefix operator -1️⃣фф--class Recover2 {}
      """,
      diagnostics: [
        DiagnosticSpec(message: "'фф--class' is not allowed in operator names", fixIts: ["remove 'фф--class'"])
      ],
      fixedSource: """
        prefix operator - Recover2 {}
        """
    )
  }

  func testRecovery173() {
    // <rdar://problem/21712891> Swift Compiler bug: String subscripts with range should require closing bracket.
    assertParse(
      #"""
      func r21712891(s : String) -> String {
        let a = s.startIndex..<s.startIndex
        _ = a
        // The specific errors produced don't actually matter, but we need to reject this.
        return "\(sℹ️[a1️⃣)"
      }
      """#,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ']' to end subscript",
          notes: [NoteSpec(message: "to match this opening '['")],
          fixIts: ["insert ']'"]
        )
      ],
      fixedSource: #"""
        func r21712891(s : String) -> String {
          let a = s.startIndex..<s.startIndex
          _ = a
          // The specific errors produced don't actually matter, but we need to reject this.
          return "\(s[a])"
        }
        """#
    )
  }

  func testRecovery174() {
    // <rdar://problem/24029542> "Postfix '.' is reserved" error message" isn't helpful
    assertParse(
      #"""
      func postfixDot(a : String) {
        _ = a.utf8
        _ = a1️⃣.   utf8
        _ = a.2️⃣
          a.3️⃣
      }
      """#,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "extraneous whitespace after '.' is not permitted",
          fixIts: ["remove whitespace"]
        ),
        DiagnosticSpec(locationMarker: "2️⃣", message: "expected name in member access", fixIts: ["insert name"]),
        DiagnosticSpec(locationMarker: "3️⃣", message: "expected name in member access", fixIts: ["insert name"]),
      ],
      fixedSource: #"""
        func postfixDot(a : String) {
          _ = a.utf8
          _ = a.utf8
          _ = a.<#identifier#>
            a.<#identifier#>
        }
        """#
    )
  }

  func testRecovery175() {
    // <rdar://problem/22290244> QoI: "UIColor." gives two issues, should only give one
    assertParse(
      #"""
      func f() { // expected-note 2{{did you mean 'f'?}}
        _ = ClassWithStaticDecls.1️⃣
      }
      """#,
      diagnostics: [
        DiagnosticSpec(message: "expected name in member access", fixIts: ["insert name"])
      ],
      fixedSource: #"""
        func f() { // expected-note 2{{did you mean 'f'?}}
          _ = ClassWithStaticDecls.<#identifier#>
        }
        """#
    )
  }

  func testRecovery176() {
    // rdar://problem/22478168
    // https://github.com/apple/swift/issues/53396
    assertParse(
      """
      func f_53396(a: Int 1️⃣== 0) {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected '=' instead of '==' to assign default value for parameter",
          fixIts: ["replace '==' with '='"]
        )
      ],
      fixedSource: """
        func f_53396(a: Int = 0) {}
        """
    )
  }

  func testRecovery177() {
    // rdar://38225184
    assertParse(
      """
      extension Collection where Element == Int 1️⃣&& Index == Int {}
      """,
      diagnostics: [
        DiagnosticSpec(
          message: "expected ',' to separate the requirements of this 'where' clause",
          fixIts: ["replace '&&' with ','"]
        )
      ],
      fixedSource: """
        extension Collection where Element == Int, Index == Int {}
        """
    )
  }

  func testRecovery179() {
    assertParse(
      """
      func testSkipUnbalancedParen() {
        1️⃣?(
      }
      """,
      diagnostics: [
        DiagnosticSpec(message: "unexpected code '?(' in function")
      ]
    )
  }

  func testRecovery180() {
    assertParse(
      """
      func testSkipToFindOpenBrace1() ℹ️{
        do { if case 1️⃣}
      }2️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected expression, '=', and expression in pattern matching",
          fixIts: ["insert expression, '=', and expression"]
        ),
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected '{' in 'if' statement",
          fixIts: ["insert '{'"]
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected '}' to end function",
          notes: [NoteSpec(message: "to match this opening '{'")],
          fixIts: ["insert '}'"]
        ),
      ],
      fixedSource: """
        func testSkipToFindOpenBrace1() {
          do { if case <#expression#> = <#expression#> {}
        }
        }
        """
    )
  }

  func testRecovery181() {
    assertParse(
      """
      func testSkipToFindOpenBrace2() ℹ️{
        do { if true {} else 1️⃣false }
      }2️⃣
      """,
      diagnostics: [
        DiagnosticSpec(
          locationMarker: "1️⃣",
          message: "expected '{' or 'if' after 'else'"
        ),
        DiagnosticSpec(
          locationMarker: "2️⃣",
          message: "expected '}' to end function",
          notes: [NoteSpec(message: "to match this opening '{'")],
          fixIts: ["insert '}'"]
        ),
      ],
      fixedSource: """
        func testSkipToFindOpenBrace2() {
          do { if true {} else false }
        }
        }
        """
    )
  }

  func testRecovery182() {
    assertParse(
      "func foo() 1️⃣bogus {}",
      diagnostics: [
        DiagnosticSpec(message: "unexpected code 'bogus' in function")
      ]
    )

    assertParse(
      "func foo() 1️⃣bogus -> Int {}",
      diagnostics: [
        DiagnosticSpec(message: "unexpected code 'bogus' in function signature")
      ]
    )
  }

  // https://github.com/swiftlang/swift-syntax/issues/1483
  func testRecovery183() {
    // Can be parsed and produces no diagnostics.
    assertParse(
      "func f<1️⃣ >() {}",
      diagnostics: [
        DiagnosticSpec(
          message: "expected generic parameter in generic parameter clause",
          fixIts: ["insert generic parameter"]
        )
      ],
      fixedSource: """
        func f<<#identifier#>>() {}
        """
    )

    // Can be parsed. Printing the node or asking for the diagnostics leads to a crash.
    assertParse(
      "func f<1️⃣>() {}",
      diagnostics: [
        DiagnosticSpec(
          message: "expected generic parameter in generic parameter clause",
          fixIts: ["insert generic parameter"]
        )
      ],
      fixedSource: """
        func f<<#identifier#>>() {}
        """
    )
  }

  // https://github.com/swiftlang/swift-syntax/pull/1484/files#r1176740738
  func testRecovery184() {
    assertParse(
      "func foo() -> Int1️⃣:",
      diagnostics: [
        DiagnosticSpec(message: "extraneous code ':' at top level")
      ]
    )
  }
}