Merge branch 'release-5.5' into cherry-pick/59070/release-5.5

Author: sheetalkamat

src/compiler/checker.ts

@@ -2193,6 +2193,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     /** Key is "/path/to/a.ts|/path/to/b.ts". */
     var amalgamatedDuplicates: Map<string, DuplicateInfoForFiles> | undefined;
     var reverseMappedCache = new Map<string, Type | undefined>();
+    var reverseHomomorphicMappedCache = new Map<string, Type | undefined>();
     var ambientModulesCache: Symbol[] | undefined;
     /**
      * List of every ambient module with a "*" wildcard.
@@ -7003,20 +7004,38 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
 
         function shouldUsePlaceholderForProperty(propertySymbol: Symbol, context: NodeBuilderContext) {
-            // Use placeholders for reverse mapped types we've either already descended into, or which
-            // are nested reverse mappings within a mapping over a non-anonymous type. The later is a restriction mostly just to
+            // Use placeholders for reverse mapped types we've either
+            // (1) already descended into, or
+            // (2) are nested reverse mappings within a mapping over a non-anonymous type, or
+            // (3) are deeply nested properties that originate from the same mapped type.
+            // Condition (2) is a restriction mostly just to
             // reduce the blowup in printback size from doing, eg, a deep reverse mapping over `Window`.
             // Since anonymous types usually come from expressions, this allows us to preserve the output
             // for deep mappings which likely come from expressions, while truncating those parts which
             // come from mappings over library functions.
+            // Condition (3) limits printing of possibly infinitely deep reverse mapped types.
+            const depth = 3;
             return !!(getCheckFlags(propertySymbol) & CheckFlags.ReverseMapped)
                 && (
                     contains(context.reverseMappedStack, propertySymbol as ReverseMappedSymbol)
                     || (
                         context.reverseMappedStack?.[0]
                         && !(getObjectFlags(last(context.reverseMappedStack).links.propertyType) & ObjectFlags.Anonymous)
                     )
+                    || isDeeplyNestedReverseMappedTypeProperty()
                 );
+            function isDeeplyNestedReverseMappedTypeProperty() {
+                if ((context.reverseMappedStack?.length ?? 0) < depth) {
+                    return false;
+                }
+                for (let i = 0; i < depth; i++) {
+                    const prop = context.reverseMappedStack![context.reverseMappedStack!.length - 1 - i];
+                    if (prop.links.mappedType.symbol !== (propertySymbol as ReverseMappedSymbol).links.mappedType.symbol) {
+                        return false;
+                    }
+                }
+                return true;
+            }
         }
 
         function addPropertyToElementList(propertySymbol: Symbol, context: NodeBuilderContext, typeElements: TypeElement[]) {
@@ -8291,11 +8310,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             const typePredicate = getTypePredicateOfSignature(signature);
             const type = getReturnTypeOfSignature(signature);
             if (context.enclosingDeclaration && (!isErrorType(type) || (context.flags & NodeBuilderFlags.AllowUnresolvedNames)) && signature.declaration && !nodeIsSynthesized(signature.declaration)) {
-                const annotation = signature.declaration && getNonlocalEffectiveReturnTypeAnnotationNode(signature.declaration);
-                // Default constructor signatures inherited from base classes return the derived class but have the base class declaration
-                // To ensure we don't serialize the wrong type we check that that return type of the signature corresponds to the declaration return type signature
-                if (annotation && getTypeFromTypeNode(context, annotation) === type) {
-                    const result = tryReuseExistingTypeNodeHelper(context, annotation);
+                const annotation = getNonlocalEffectiveReturnTypeAnnotationNode(signature.declaration);
+                if (annotation) {
+                    const result = tryReuseExistingTypeNode(context, annotation, type, context.enclosingDeclaration);
                     if (result) {
                         return result;
                     }
@@ -8805,7 +8822,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     );
                 }
                 if (isNamedDeclaration(node) && node.name.kind === SyntaxKind.ComputedPropertyName && !isLateBindableName(node.name)) {
-                    if (!(context.flags & NodeBuilderFlags.AllowUnresolvedNames && hasDynamicName(node) && isEntityNameExpression(node.name.expression) && checkComputedPropertyName(node.name).flags & TypeFlags.Any)) {
+                    if (!hasDynamicName(node)) {
+                        return visitEachChild(node, visitExistingNodeTreeSymbols);
+                    }
+                    if (!(context.flags & NodeBuilderFlags.AllowUnresolvedNames && isEntityNameExpression(node.name.expression) && checkComputedPropertyName(node.name).flags & TypeFlags.Any)) {
                         return undefined;
                     }
                 }
@@ -8949,7 +8969,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     if (result) {
                         if (result.pos !== -1 || result.end !== -1) {
                             if (result === nodes) {
-                                result = factory.createNodeArray(nodes, nodes.hasTrailingComma);
+                                result = factory.createNodeArray(nodes.slice(), nodes.hasTrailingComma);
                             }
                             setTextRangePosEnd(result, -1, -1);
                         }
@@ -15923,7 +15943,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     }
 
     function createSignatureTypeMapper(signature: Signature, typeArguments: readonly Type[] | undefined): TypeMapper {
-        return createTypeMapper(signature.typeParameters!, typeArguments);
+        return createTypeMapper(sameMap(signature.typeParameters!, tp => tp.mapper ? instantiateType(tp, tp.mapper) : tp), typeArguments);
     }
 
     function getErasedSignature(signature: Signature): Signature {
@@ -25604,11 +25624,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
      */
     function inferTypeForHomomorphicMappedType(source: Type, target: MappedType, constraint: IndexType): Type | undefined {
         const cacheKey = source.id + "," + target.id + "," + constraint.id;
-        if (reverseMappedCache.has(cacheKey)) {
-            return reverseMappedCache.get(cacheKey);
+        if (reverseHomomorphicMappedCache.has(cacheKey)) {
+            return reverseHomomorphicMappedCache.get(cacheKey);
         }
         const type = createReverseMappedType(source, target, constraint);
-        reverseMappedCache.set(cacheKey, type);
+        reverseHomomorphicMappedCache.set(cacheKey, type);
         return type;
     }
 
@@ -33316,7 +33336,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
 
         checkJsxPreconditions(node);
 
-        markLinkedReferences(node, ReferenceHint.Jsx);
+        markJsxAliasReferenced(node);
 
         if (isNodeOpeningLikeElement) {
             const jsxOpeningLikeNode = node;
@@ -49219,11 +49239,17 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             forEachNodeRecursively(node, checkIdentifiers);
         }
 
+        function isExpressionNodeOrShorthandPropertyAssignmentName(node: Identifier) {
+            // TODO(jakebailey): Just use isExpressionNode once that considers these identifiers to be expressions.
+            return isExpressionNode(node)
+                || isShorthandPropertyAssignment(node.parent) && (node.parent.objectAssignmentInitializer ?? node.parent.name) === node;
+        }
+
         function checkSingleIdentifier(node: Node) {
             const nodeLinks = getNodeLinks(node);
             nodeLinks.calculatedFlags |= NodeCheckFlags.ConstructorReference | NodeCheckFlags.CapturedBlockScopedBinding | NodeCheckFlags.BlockScopedBindingInLoop;
-            if (isIdentifier(node) && isExpressionNode(node) && !(isPropertyAccessExpression(node.parent) && node.parent.name === node)) {
-                const s = getSymbolAtLocation(node, /*ignoreErrors*/ true);
+            if (isIdentifier(node) && isExpressionNodeOrShorthandPropertyAssignmentName(node) && !(isPropertyAccessExpression(node.parent) && node.parent.name === node)) {
+                const s = getResolvedSymbol(node);
                 if (s && s !== unknownSymbol) {
                     checkIdentifierCalculateNodeCheckFlags(node, s);
                 }

src/compiler/commandLineParser.ts

@@ -800,6 +800,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         type: "boolean",
         affectsEmit: true,
         affectsBuildInfo: true,
+        affectsSourceFile: true,
         category: Diagnostics.Emit,
         description: Diagnostics.Allow_importing_helper_functions_from_tslib_once_per_project_instead_of_including_them_per_file,
         defaultValueDescription: false,
@@ -1270,6 +1271,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         affectsEmit: true,
         affectsBuildInfo: true,
         affectsModuleResolution: true,
+        affectsSourceFile: true,
         category: Diagnostics.Language_and_Environment,
         description: Diagnostics.Specify_module_specifier_used_to_import_the_JSX_factory_functions_when_using_jsx_Colon_react_jsx_Asterisk,
         defaultValueDescription: "react",

src/compiler/factory/nodeChildren.ts

@@ -1,25 +1,61 @@
 import {
+    Debug,
     emptyArray,
     isNodeKind,
     Node,
+    SourceFileLike,
+    SyntaxKind,
+    SyntaxList,
 } from "../_namespaces/ts.js";
 
-const nodeChildren = new WeakMap<Node, readonly Node[] | undefined>();
+const sourceFileToNodeChildren = new WeakMap<SourceFileLike, WeakMap<Node, readonly Node[] | undefined>>();
 
 /** @internal */
-export function getNodeChildren(node: Node): readonly Node[] | undefined {
-    if (!isNodeKind(node.kind)) return emptyArray;
+export function getNodeChildren(node: Node, sourceFile: SourceFileLike): readonly Node[] | undefined {
+    const kind = node.kind;
+    if (!isNodeKind(kind)) {
+        return emptyArray;
+    }
+    if (kind === SyntaxKind.SyntaxList) {
+        return (node as SyntaxList)._children;
+    }
 
-    return nodeChildren.get(node);
+    return sourceFileToNodeChildren.get(sourceFile)?.get(node);
 }
 
 /** @internal */
-export function setNodeChildren(node: Node, children: readonly Node[]): readonly Node[] {
-    nodeChildren.set(node, children);
+export function setNodeChildren(node: Node, sourceFile: SourceFileLike, children: readonly Node[]): readonly Node[] {
+    if (node.kind === SyntaxKind.SyntaxList) {
+        // SyntaxList children are always eagerly created in the process of
+        // creating their parent's `children` list. We shouldn't need to set them here.
+        Debug.fail("Should not need to re-set the children of a SyntaxList.");
+    }
+
+    let map = sourceFileToNodeChildren.get(sourceFile);
+    if (map === undefined) {
+        map = new WeakMap();
+        sourceFileToNodeChildren.set(sourceFile, map);
+    }
+    map.set(node, children);
     return children;
 }
 
 /** @internal */
-export function unsetNodeChildren(node: Node) {
-    nodeChildren.delete(node);
+export function unsetNodeChildren(node: Node, origSourceFile: SourceFileLike) {
+    if (node.kind === SyntaxKind.SyntaxList) {
+        // Syntax lists are synthesized and we store their children directly on them.
+        // They are a special case where we expect incremental parsing to toss them away entirely
+        // if a change intersects with their containing parents.
+        Debug.fail("Did not expect to unset the children of a SyntaxList.");
+    }
+    sourceFileToNodeChildren.get(origSourceFile)?.delete(node);
+}
+
+/** @internal */
+export function transferSourceFileChildren(sourceFile: SourceFileLike, targetSourceFile: SourceFileLike) {
+    const map = sourceFileToNodeChildren.get(sourceFile);
+    if (map !== undefined) {
+        sourceFileToNodeChildren.delete(sourceFile);
+        sourceFileToNodeChildren.set(targetSourceFile, map);
+    }
 }

src/compiler/factory/nodeFactory.ts

@@ -387,7 +387,6 @@ import {
     setEmitFlags,
     setIdentifierAutoGenerate,
     setIdentifierTypeArguments,
-    setNodeChildren,
     setParent,
     setTextRange,
     ShorthandPropertyAssignment,
@@ -6211,7 +6210,7 @@ export function createNodeFactory(flags: NodeFactoryFlags, baseFactory: BaseNode
     // @api
     function createSyntaxList(children: readonly Node[]) {
         const node = createBaseNode<SyntaxList>(SyntaxKind.SyntaxList);
-        setNodeChildren(node, children);
+        node._children = children;
         return node;
     }
 

src/compiler/parser.ts

@@ -369,6 +369,7 @@ import {
     tokenIsIdentifierOrKeywordOrGreaterThan,
     tokenToString,
     tracing,
+    transferSourceFileChildren,
     TransformFlags,
     TryStatement,
     TupleTypeNode,
@@ -2637,7 +2638,7 @@ namespace Parser {
     function createIdentifier(isIdentifier: boolean, diagnosticMessage?: DiagnosticMessage, privateIdentifierDiagnosticMessage?: DiagnosticMessage): Identifier {
         if (isIdentifier) {
             identifierCount++;
-            const pos = getNodePos();
+            const pos = scanner.hasLeadingAsterisks() ? scanner.getTokenStart() : getNodePos();
             // Store original token kind if it is not just an Identifier so we can report appropriate error later in type checker
             const originalKeywordKind = token();
             const text = internIdentifier(scanner.getTokenValue());
@@ -9949,6 +9950,7 @@ namespace IncrementalParser {
             aggressiveChecks,
         );
         result.impliedNodeFormat = sourceFile.impliedNodeFormat;
+        transferSourceFileChildren(sourceFile, result);
         return result;
     }
 
@@ -10001,9 +10003,9 @@ namespace IncrementalParser {
         }
     }
 
-    function moveElementEntirelyPastChangeRange(element: Node, isArray: false, delta: number, oldText: string, newText: string, aggressiveChecks: boolean): void;
-    function moveElementEntirelyPastChangeRange(element: NodeArray<Node>, isArray: true, delta: number, oldText: string, newText: string, aggressiveChecks: boolean): void;
-    function moveElementEntirelyPastChangeRange(element: Node | NodeArray<Node>, isArray: boolean, delta: number, oldText: string, newText: string, aggressiveChecks: boolean) {
+    function moveElementEntirelyPastChangeRange(element: Node, origSourceFile: SourceFile, isArray: false, delta: number, oldText: string, newText: string, aggressiveChecks: boolean): void;
+    function moveElementEntirelyPastChangeRange(element: NodeArray<Node>, origSourceFile: SourceFile, isArray: true, delta: number, oldText: string, newText: string, aggressiveChecks: boolean): void;
+    function moveElementEntirelyPastChangeRange(element: Node | NodeArray<Node>, origSourceFile: SourceFile, isArray: boolean, delta: number, oldText: string, newText: string, aggressiveChecks: boolean) {
         if (isArray) {
             visitArray(element as NodeArray<Node>);
         }
@@ -10020,7 +10022,7 @@ namespace IncrementalParser {
 
             // Ditch any existing LS children we may have created.  This way we can avoid
             // moving them forward.
-            unsetNodeChildren(node);
+            unsetNodeChildren(node, origSourceFile);
 
             setTextRangePosEnd(node, node.pos + delta, node.end + delta);
 
@@ -10167,7 +10169,7 @@ namespace IncrementalParser {
             if (child.pos > changeRangeOldEnd) {
                 // Node is entirely past the change range.  We need to move both its pos and
                 // end, forward or backward appropriately.
-                moveElementEntirelyPastChangeRange(child, /*isArray*/ false, delta, oldText, newText, aggressiveChecks);
+                moveElementEntirelyPastChangeRange(child, sourceFile, /*isArray*/ false, delta, oldText, newText, aggressiveChecks);
                 return;
             }
 
@@ -10177,7 +10179,7 @@ namespace IncrementalParser {
             const fullEnd = child.end;
             if (fullEnd >= changeStart) {
                 markAsIntersectingIncrementalChange(child);
-                unsetNodeChildren(child);
+                unsetNodeChildren(child, sourceFile);
 
                 // Adjust the pos or end (or both) of the intersecting element accordingly.
                 adjustIntersectingElement(child, changeStart, changeRangeOldEnd, changeRangeNewEnd, delta);
@@ -10200,7 +10202,7 @@ namespace IncrementalParser {
             if (array.pos > changeRangeOldEnd) {
                 // Array is entirely after the change range.  We need to move it, and move any of
                 // its children.
-                moveElementEntirelyPastChangeRange(array, /*isArray*/ true, delta, oldText, newText, aggressiveChecks);
+                moveElementEntirelyPastChangeRange(array, sourceFile, /*isArray*/ true, delta, oldText, newText, aggressiveChecks);
                 return;
             }
 

src/compiler/performanceCore.ts

@@ -31,11 +31,14 @@ function tryGetPerformance() {
     if (isNodeLikeSystem()) {
         try {
             // By default, only write native events when generating a cpu profile or using the v8 profiler.
-            const { performance } = require("perf_hooks") as typeof import("perf_hooks");
-            return {
-                shouldWriteNativeEvents: false,
-                performance,
-            };
+            // Some environments may polyfill this module with an empty object; verify the object has the expected shape.
+            const { performance } = require("perf_hooks") as Partial<typeof import("perf_hooks")>;
+            if (performance) {
+                return {
+                    shouldWriteNativeEvents: false,
+                    performance,
+                };
+            }
         }
         catch {
             // ignore errors

src/compiler/scanner.ts

@@ -112,6 +112,8 @@ export interface Scanner {
     resetTokenState(pos: number): void;
     /** @internal */
     setSkipJsDocLeadingAsterisks(skip: boolean): void;
+    /** @internal */
+    hasLeadingAsterisks(): boolean;
     // Invokes the provided callback then unconditionally restores the scanner to the state it
     // was in immediately prior to invoking the callback.  The result of invoking the callback
     // is returned from this function.
@@ -1042,6 +1044,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
 
     var commentDirectives: CommentDirective[] | undefined;
     var skipJsDocLeadingAsterisks = 0;
+    var asteriskSeen = false;
 
     var scriptKind = ScriptKind.Unknown;
     var jsDocParsingMode = JSDocParsingMode.ParseAll;
@@ -1096,6 +1099,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
         resetTokenState,
         setTextPos: resetTokenState,
         setSkipJsDocLeadingAsterisks,
+        hasLeadingAsterisks,
         tryScan,
         lookAhead,
         scanRange,
@@ -1877,7 +1881,7 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
     function scan(): SyntaxKind {
         fullStartPos = pos;
         tokenFlags = TokenFlags.None;
-        let asteriskSeen = false;
+        asteriskSeen = false;
         while (true) {
             tokenStart = pos;
             if (pos >= end) {
@@ -4004,6 +4008,10 @@ export function createScanner(languageVersion: ScriptTarget, skipTrivia: boolean
     function setSkipJsDocLeadingAsterisks(skip: boolean) {
         skipJsDocLeadingAsterisks += skip ? 1 : -1;
     }
+
+    function hasLeadingAsterisks() {
+        return asteriskSeen;
+    }
 }
 
 function codePointAt(s: string, i: number): number {