fix merging of function and derived class (#47170)

Author: Zzzen

src/compiler/checker.ts

@@ -9900,7 +9900,8 @@ namespace ts {
         }
 
         function getBaseTypeNodeOfClass(type: InterfaceType): ExpressionWithTypeArguments | undefined {
-            return getEffectiveBaseTypeNode(type.symbol.valueDeclaration as ClassLikeDeclaration);
+            const decl = getClassLikeDeclarationOfSymbol(type.symbol);
+            return decl && getEffectiveBaseTypeNode(decl);
         }
 
         function getConstructorsForTypeArguments(type: Type, typeArgumentNodes: readonly TypeNode[] | undefined, location: Node): readonly Signature[] {
@@ -9926,8 +9927,8 @@ namespace ts {
          */
         function getBaseConstructorTypeOfClass(type: InterfaceType): Type {
             if (!type.resolvedBaseConstructorType) {
-                const decl = type.symbol.valueDeclaration as ClassLikeDeclaration;
-                const extended = getEffectiveBaseTypeNode(decl);
+                const decl = getClassLikeDeclarationOfSymbol(type.symbol);
+                const extended = decl && getEffectiveBaseTypeNode(decl);
                 const baseTypeNode = getBaseTypeNodeOfClass(type);
                 if (!baseTypeNode) {
                     return type.resolvedBaseConstructorType = undefinedType;

tests/baselines/reference/classFunctionMerging2.js

@@ -0,0 +1,18 @@
+//// [classFunctionMerging2.ts]
+declare abstract class A {
+    constructor(p: number);
+    a: number;
+}
+
+declare function B(p: string): B;
+declare class B extends A {
+    constructor(p: string);
+    b: number;
+}
+
+let b = new B("Hey")
+console.log(b.a)
+
+//// [classFunctionMerging2.js]
+var b = new B("Hey");
+console.log(b.a);

tests/baselines/reference/classFunctionMerging2.symbols

@@ -0,0 +1,39 @@
+=== tests/cases/compiler/classFunctionMerging2.ts ===
+declare abstract class A {
+>A : Symbol(A, Decl(classFunctionMerging2.ts, 0, 0))
+
+    constructor(p: number);
+>p : Symbol(p, Decl(classFunctionMerging2.ts, 1, 16))
+
+    a: number;
+>a : Symbol(A.a, Decl(classFunctionMerging2.ts, 1, 27))
+}
+
+declare function B(p: string): B;
+>B : Symbol(B, Decl(classFunctionMerging2.ts, 3, 1), Decl(classFunctionMerging2.ts, 5, 33))
+>p : Symbol(p, Decl(classFunctionMerging2.ts, 5, 19))
+>B : Symbol(B, Decl(classFunctionMerging2.ts, 3, 1), Decl(classFunctionMerging2.ts, 5, 33))
+
+declare class B extends A {
+>B : Symbol(B, Decl(classFunctionMerging2.ts, 3, 1), Decl(classFunctionMerging2.ts, 5, 33))
+>A : Symbol(A, Decl(classFunctionMerging2.ts, 0, 0))
+
+    constructor(p: string);
+>p : Symbol(p, Decl(classFunctionMerging2.ts, 7, 16))
+
+    b: number;
+>b : Symbol(B.b, Decl(classFunctionMerging2.ts, 7, 27))
+}
+
+let b = new B("Hey")
+>b : Symbol(b, Decl(classFunctionMerging2.ts, 11, 3))
+>B : Symbol(B, Decl(classFunctionMerging2.ts, 3, 1), Decl(classFunctionMerging2.ts, 5, 33))
+
+console.log(b.a)
+>console.log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>console : Symbol(console, Decl(lib.dom.d.ts, --, --))
+>log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
+>b.a : Symbol(A.a, Decl(classFunctionMerging2.ts, 1, 27))
+>b : Symbol(b, Decl(classFunctionMerging2.ts, 11, 3))
+>a : Symbol(A.a, Decl(classFunctionMerging2.ts, 1, 27))
+

tests/baselines/reference/classFunctionMerging2.types

@@ -0,0 +1,41 @@
+=== tests/cases/compiler/classFunctionMerging2.ts ===
+declare abstract class A {
+>A : A
+
+    constructor(p: number);
+>p : number
+
+    a: number;
+>a : number
+}
+
+declare function B(p: string): B;
+>B : typeof B
+>p : string
+
+declare class B extends A {
+>B : B
+>A : A
+
+    constructor(p: string);
+>p : string
+
+    b: number;
+>b : number
+}
+
+let b = new B("Hey")
+>b : B
+>new B("Hey") : B
+>B : typeof B
+>"Hey" : "Hey"
+
+console.log(b.a)
+>console.log(b.a) : void
+>console.log : (...data: any[]) => void
+>console : Console
+>log : (...data: any[]) => void
+>b.a : number
+>b : B
+>a : number
+

tests/cases/compiler/classFunctionMerging2.ts

@@ -0,0 +1,13 @@
+declare abstract class A {
+    constructor(p: number);
+    a: number;
+}
+
+declare function B(p: string): B;
+declare class B extends A {
+    constructor(p: string);
+    b: number;
+}
+
+let b = new B("Hey")
+console.log(b.a)