Only transform expando assignments that wont be represented elsewhere in the emit already (#3741)

Author: weswigham

internal/transformers/declarations/transform.go

@@ -2216,6 +2216,14 @@ func (tx *DeclarationTransformer) transformExpandoAssignment(node *ast.BinaryExp
 		return nil
 	}
 
+	if ast.IsFunctionDeclaration(declaration) && declaration.FunctionLikeData().FullSignature != nil {
+		return nil
+	}
+
+	if ast.IsVariableDeclaration(declaration) && !ast.IsFunctionLike(declaration.Initializer()) {
+		return nil // We're going to add a type, no need to dupe members with a namespace
+	}
+
 	host := declaration.Symbol()
 	if host == nil {
 		return nil

testdata/baselines/reference/compiler/jsExpandoAssignmentElementAccess.js

@@ -13,41 +13,3 @@ declare var x: {
     if: number;
     else: number;
 };
-declare namespace x {
-    var _a: number;
-    export { _a as if };
-}
-declare namespace x {
-    var _b: number;
-    export { _b as else };
-}
-
-
-//// [DtsFileErrors]
-
-
-repro.d.ts(1,13): error TS2300: Duplicate identifier 'x'.
-repro.d.ts(5,19): error TS2300: Duplicate identifier 'x'.
-repro.d.ts(9,19): error TS2300: Duplicate identifier 'x'.
-
-
-==== repro.d.ts (3 errors) ====
-    declare var x: {
-                ~
-!!! error TS2300: Duplicate identifier 'x'.
-        if: number;
-        else: number;
-    };
-    declare namespace x {
-                      ~
-!!! error TS2300: Duplicate identifier 'x'.
-        var _a: number;
-        export { _a as if };
-    }
-    declare namespace x {
-                      ~
-!!! error TS2300: Duplicate identifier 'x'.
-        var _b: number;
-        export { _b as else };
-    }
-    

testdata/baselines/reference/submodule/conformance/jsdocImplements_class.js

@@ -87,13 +87,6 @@ declare var Ns: {
         };
     };
 };
-declare namespace Ns {
-    var C1: {
-        new (): {
-            method(): number;
-        };
-    };
-}
 /** @implements {A} */
 declare var C2: {
     new (): {
@@ -117,10 +110,3 @@ declare class CC {
     };
 }
 declare var C5: any;
-declare namespace Ns {
-    var C5: {
-        new (): {
-            method(): number;
-        };
-    };
-}

testdata/baselines/reference/submodule/conformance/typeFromPropertyAssignment39.js

@@ -14,42 +14,3 @@ declare const foo: {
         blah: number;
     };
 };
-declare namespace foo {
-    var baz: {
-        blah: number;
-    };
-}
-declare namespace foo {
-    var blah: number;
-}
-
-
-//// [DtsFileErrors]
-
-
-a.d.ts(1,15): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-a.d.ts(6,19): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-a.d.ts(11,19): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-
-
-==== a.d.ts (3 errors) ====
-    declare const foo: {
-                  ~~~
-!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-        baz: {
-            blah: number;
-        };
-    };
-    declare namespace foo {
-                      ~~~
-!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-        var baz: {
-            blah: number;
-        };
-    }
-    declare namespace foo {
-                      ~~~
-!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-        var blah: number;
-    }
-    

testdata/baselines/reference/submoduleAccepted/conformance/jsdocImplements_class.js.diff

@@ -4,6 +4,14 @@
  /** @implements {A} */
  declare class B3 implements A {
  }
+-declare namespace Ns {
+-    export { C1 };
+-    export let C5: {
+-        new (): {
+-            method(): number;
+-        };
+-    };
+-}
 +declare var Ns: {
 +    /** @implements {A} */
 +    C1: {
@@ -18,14 +26,9 @@
 +        };
 +    };
 +};
- declare namespace Ns {
--    export { C1 };
--    export let C5: {
-+    var C1: {
-         new (): {
-             method(): number;
-         };
-@@= skipped -14, +27 lines =@@
+ /** @implements {A} */
+ declare var C2: {
+     new (): {
          method(): number;
      };
  };
@@ -43,7 +46,7 @@
  declare class CC {
      /** @implements {A} */
      C4: {
-@@= skipped -12, +17 lines =@@
+@@= skipped -26, +37 lines =@@
      };
  }
  declare var C5: any;
@@ -52,10 +55,4 @@
 -}
 -declare class C3 implements A {
 -    method(): number;
-+declare namespace Ns {
-+    var C5: {
-+        new (): {
-+            method(): number;
-+        };
-+    };
- }
+-}

testdata/baselines/reference/submoduleTriaged/conformance/typeFromPropertyAssignment39.js.diff

@@ -13,43 +13,4 @@
 +    baz: {
 +        blah: number;
 +    };
-+};
-+declare namespace foo {
-+    var baz: {
-+        blah: number;
-+    };
-+}
-+declare namespace foo {
-+    var blah: number;
-+}
-+
-+
-+//// [DtsFileErrors]
-+
-+
-+a.d.ts(1,15): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+a.d.ts(6,19): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+a.d.ts(11,19): error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+
-+
-+==== a.d.ts (3 errors) ====
-+    declare const foo: {
-+                  ~~~
-+!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+        baz: {
-+            blah: number;
-+        };
-+    };
-+    declare namespace foo {
-+                      ~~~
-+!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+        var baz: {
-+            blah: number;
-+        };
-+    }
-+    declare namespace foo {
-+                      ~~~
-+!!! error TS2451: Cannot redeclare block-scoped variable 'foo'.
-+        var blah: number;
-+    }
-+    
++};