Test cast function

Author: groue

Tests/GRDBTests/AssociationAggregateTests.swift

@@ -1511,6 +1511,30 @@ class AssociationAggregateTests: GRDBTestCase {
         }
     }
 
+    func testCast() throws {
+        let dbQueue = try makeDatabaseQueue()
+        try dbQueue.read { db in
+            do {
+                let request = Team.annotated(with: cast(Team.players.count, as: .real))
+                try assertEqualSQL(db, request, """
+                    SELECT "team".*, CAST(COUNT(DISTINCT "player"."id") AS REAL) AS "playerCount" \
+                    FROM "team" \
+                    LEFT JOIN "player" ON "player"."teamId" = "team"."id" \
+                    GROUP BY "team"."id"
+                    """)
+            }
+            do {
+                let request = Team.annotated(with: cast(Team.players.count, as: .real).forKey("foo"))
+                try assertEqualSQL(db, request, """
+                    SELECT "team".*, CAST(COUNT(DISTINCT "player"."id") AS REAL) AS "foo" \
+                    FROM "team" \
+                    LEFT JOIN "player" ON "player"."teamId" = "team"."id" \
+                    GROUP BY "team"."id"
+                    """)
+            }
+        }
+    }
+    
     func testLength() throws {
         let dbQueue = try makeDatabaseQueue()
         try dbQueue.read { db in

Tests/GRDBTests/QueryInterfaceExpressionsTests.swift

@@ -1526,7 +1526,15 @@ class QueryInterfaceExpressionsTests: GRDBTestCase {
             sql(dbQueue, tableRequest.select(average(Col.age / 2, filter: Col.age > 0))),
             "SELECT AVG(\"age\" / 2) FILTER (WHERE \"age\" > 0) FROM \"readers\"")
     }
-
+    
+    func testCastExpression() throws {
+        let dbQueue = try makeDatabaseQueue()
+        
+        XCTAssertEqual(
+            sql(dbQueue, tableRequest.select(cast(Col.name, as: .blob))),
+            "SELECT CAST(\"name\" AS BLOB) FROM \"readers\"")
+    }
+    
     func testLengthExpression() throws {
         let dbQueue = try makeDatabaseQueue()
 

Tests/GRDBTests/SQLExpressionIsConstantTests.swift

@@ -274,6 +274,10 @@ class SQLExpressionIsConstantTests: GRDBTestCase {
         XCTAssertFalse((Column("a") - 2.databaseValue).isConstantInRequest)
         XCTAssertFalse((1.databaseValue - Column("a")).isConstantInRequest)
 
+        // CAST
+        XCTAssertTrue(cast(1.databaseValue, as: .real).isConstantInRequest)
+        XCTAssertFalse(cast(Column("a"), as: .real).isConstantInRequest)
+
         // SQLExpressionCollate
         XCTAssertTrue("foo".databaseValue.collating(.binary).isConstantInRequest)
         XCTAssertFalse(Column("a").collating(.binary).isConstantInRequest)