Merge pull request #1760 from Microsoft/typeAliasDoesntMakeModuleInstantiated

Type alias declaration is type only declaration and doesnt make module instantiated

Author: sheetalkamat

src/compiler/binder.ts

@@ -9,8 +9,8 @@ module ts {
 
     export function getModuleInstanceState(node: Node): ModuleInstanceState {
         // A module is uninstantiated if it contains only 
-        // 1. interface declarations
-        if (node.kind === SyntaxKind.InterfaceDeclaration) {
+        // 1. interface declarations, type alias declarations
+        if (node.kind === SyntaxKind.InterfaceDeclaration || node.kind === SyntaxKind.TypeAliasDeclaration) {
             return ModuleInstanceState.NonInstantiated;
         }
         // 2. const enum declarations don't make module instantiated

tests/baselines/reference/typeAliasDoesntMakeModuleInstantiated.js

@@ -0,0 +1,13 @@
+//// [typeAliasDoesntMakeModuleInstantiated.ts]
+declare module m {
+    // type alias declaration here shouldnt make the module declaration instantiated
+    type Selector = string| string[] |Function;
+
+    export interface IStatic {
+        (selector: any /* Selector */): IInstance;
+    }
+    export interface IInstance { }
+}
+declare var m: m.IStatic; // Should be ok to have var 'm' as module is non instantiated
+
+//// [typeAliasDoesntMakeModuleInstantiated.js]

tests/baselines/reference/typeAliasDoesntMakeModuleInstantiated.types

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/typeAliasDoesntMakeModuleInstantiated.ts ===
+declare module m {
+>m : IStatic
+
+    // type alias declaration here shouldnt make the module declaration instantiated
+    type Selector = string| string[] |Function;
+>Selector : string | Function | string[]
+>Function : Function
+
+    export interface IStatic {
+>IStatic : IStatic
+
+        (selector: any /* Selector */): IInstance;
+>selector : any
+>IInstance : IInstance
+    }
+    export interface IInstance { }
+>IInstance : IInstance
+}
+declare var m: m.IStatic; // Should be ok to have var 'm' as module is non instantiated
+>m : m.IStatic
+>m : unknown
+>IStatic : m.IStatic
+

tests/cases/compiler/typeAliasDoesntMakeModuleInstantiated.ts

@@ -0,0 +1,10 @@
+declare module m {
+    // type alias declaration here shouldnt make the module declaration instantiated
+    type Selector = string| string[] |Function;
+
+    export interface IStatic {
+        (selector: any /* Selector */): IInstance;
+    }
+    export interface IInstance { }
+}
+declare var m: m.IStatic; // Should be ok to have var 'm' as module is non instantiated