Merge pull request #2 from fred-sch/main

Insert does not fail if model is entirely empty

Author: patrick-zippenfenig

Sources/ClickHouseVapor/ClickHouseModel.swift

@@ -64,12 +64,14 @@ extension ClickHouseModel {
         }
     }
 
+    /// Insert data into table. Insert will fail if columns differ in the amount of elements.
     public func insert(on connection: ClickHouseConnectionProtocol, engine: ClickHouseEngine? = nil)  throws -> EventLoopFuture<Void> {
         let fields = properties
         let engine = engine ?? Self.engine
 
-        guard let rowCount = fields.first?.count else {
-            // no columns -> nothing to do
+        let rowCount = self.count
+        if  rowCount == 0 {
+            // no rows or no columns -> nothing to do
             return connection.eventLoop.makeSucceededFuture(())
         }
 
@@ -80,6 +82,7 @@ extension ClickHouseModel {
             }
             return rowCount == 0 ? nil : ClickHouseColumn(field.key, field.getClickHouseArray())
         }
+        
         return connection.insert(into: engine.tableWithDatabase, data: data)
     }
 

Sources/ClickHouseVapor/ClickHouseVaporError.swift

@@ -5,7 +5,7 @@
 //  Created by Patrick Zippenfenig on 2020-11-11.
 //
 
-public enum ClickHouseVaporError: Error {
+public enum ClickHouseVaporError: Error, Equatable {
     case mismatchingDataType(columnName: String)
     case mismatchingRowCount(count: Int, expected: Int)
 }

Tests/ClickHouseVaporTests/ClickHouseVaporTests.swift

@@ -52,7 +52,8 @@ final class ClickHouseVaporTests: XCTestCase {
     static var allTests = [
         ("testPing", testPing),
         ("testModel", testModel),
-        ("testModelMissesColumns", testModelMissesColumns)
+        ("testDifferingRowsInsert", testDifferingRowsInsert),
+        ("testEmptyModelInsert", testEmptyModelInsert)
     ]
 
     func testPing() {
@@ -111,8 +112,8 @@ final class ClickHouseVaporTests: XCTestCase {
         XCTAssertEqual(model3.timestamp, model2.timestamp)
     }
 
-    /// model should fail if insert with empty columns is tried
-    public func testModelMissesColumns() {
+    /// insert should fail if some columns are not set, but others are
+    public func testDifferingRowsInsert() {
         let app = Application(.testing)
         defer { app.shutdown() }
         try! app.configureClickHouseDatabases()
@@ -125,11 +126,40 @@ final class ClickHouseVaporTests: XCTestCase {
 
 
         model.id = [ "x010", "ax51", "cd22" ]
-        model.fixed = [ "", "123456", "12345678901234" ]
+        model.fixed = [ "", "12345678901234" ]
+        model.timestamp = [ 100, 200, 300 ]
         model.temperature = [ 11.1, 10.4, 8.9 ]
 
         try! TestModel.createTable(on: app.clickHouse).wait()
-        XCTAssertThrowsError(try model.insert(on: app.clickHouse).wait(), "\(ClickHouseVaporError.mismatchingRowCount(count: 0, expected: 3))")
+        
+        var thrownError : Error?
+        // insert should fail if one tries to insert columns with different amount of rows
+        XCTAssertThrowsError(try model.insert(on: app.clickHouse).wait()) {
+            thrownError = $0
+        }
+        // check that we get correct error message
+        XCTAssertEqual(thrownError as! ClickHouseVaporError, ClickHouseVaporError.mismatchingRowCount(count: 2, expected: 3))
+    }
+    
+    
+    /// insert should not fail if the complete model is empty
+    public func testEmptyModelInsert() {
+        let app = Application(.testing)
+        defer { app.shutdown() }
+        try! app.configureClickHouseDatabases()
+        app.logger.logLevel = .trace
+        
+        let model = TestModel()
+        
+        // drop table to ensure unit test
+        try! TestModel.deleteTable(on: app.clickHouse).wait()
+        
+        try! TestModel.createTable(on: app.clickHouse).wait()
+        
+        // insert should not fail if all columns are empty
+        XCTAssertNoThrow(try model.insert(on: app.clickHouse).wait())
     }
+    
+    
 
 }