Type-only namespace imports

Author: andrewbranch

src/compiler/checker.ts

@@ -2227,7 +2227,8 @@ namespace ts {
 
         function getTargetOfNamespaceImport(node: NamespaceImport, dontResolveAlias: boolean): Symbol | undefined {
             const moduleSpecifier = node.parent.parent.moduleSpecifier;
-            return resolveESModuleSymbol(resolveExternalModuleName(node, moduleSpecifier), moduleSpecifier, dontResolveAlias, /*suppressUsageError*/ false);
+            const moduleSymbol = resolveESModuleSymbol(resolveExternalModuleName(node, moduleSpecifier), moduleSpecifier, dontResolveAlias, /*suppressUsageError*/ false);
+            return moduleSymbol && node.parent.isTypeOnly ? createTypeOnlySymbol(moduleSymbol) : moduleSymbol;
         }
 
         // This function creates a synthetic symbol that combines the value side of one symbol with the

tests/baselines/reference/importClause_namespaceImport.errors.txt

@@ -0,0 +1,34 @@
+/b.ts(2,1): error TS2708: Cannot use namespace 'types' as a value.
+/b.ts(3,1): error TS2708: Cannot use namespace 'types' as a value.
+/b.ts(4,14): error TS2694: Namespace '"/a"' has no exported member 'Value'.
+/b.ts(5,7): error TS2741: Property 'a' is missing in type '{}' but required in type 'A'.
+/b.ts(6,7): error TS2741: Property 'b' is missing in type '{}' but required in type 'B'.
+
+
+==== /a.ts (0 errors) ====
+    export class A { a!: string }
+    export class B { b!: number }
+    export type C<T> = T;
+    export const Value = {};
+    
+==== /b.ts (5 errors) ====
+    import type * as types from './a';
+    types;
+    ~~~~~
+!!! error TS2708: Cannot use namespace 'types' as a value.
+    types.Value;
+    ~~~~~
+!!! error TS2708: Cannot use namespace 'types' as a value.
+    let v: types.Value;
+                 ~~~~~
+!!! error TS2694: Namespace '"/a"' has no exported member 'Value'.
+    const a: types.A = {};
+          ~
+!!! error TS2741: Property 'a' is missing in type '{}' but required in type 'A'.
+!!! related TS2728 /a.ts:1:18: 'a' is declared here.
+    const b: types.B = {};
+          ~
+!!! error TS2741: Property 'b' is missing in type '{}' but required in type 'B'.
+!!! related TS2728 /a.ts:2:18: 'b' is declared here.
+    const c: types.C<string> = "";
+    

tests/baselines/reference/importClause_namespaceImport.js

@@ -0,0 +1,43 @@
+//// [tests/cases/conformance/externalModules/typeOnly/importClause_namespaceImport.ts] ////
+
+//// [a.ts]
+export class A { a!: string }
+export class B { b!: number }
+export type C<T> = T;
+export const Value = {};
+
+//// [b.ts]
+import type * as types from './a';
+types;
+types.Value;
+let v: types.Value;
+const a: types.A = {};
+const b: types.B = {};
+const c: types.C<string> = "";
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+var A = /** @class */ (function () {
+    function A() {
+    }
+    return A;
+}());
+exports.A = A;
+var B = /** @class */ (function () {
+    function B() {
+    }
+    return B;
+}());
+exports.B = B;
+exports.Value = {};
+//// [b.js]
+"use strict";
+exports.__esModule = true;
+types;
+types.Value;
+var v;
+var a = {};
+var b = {};
+var c = "";

tests/baselines/reference/importClause_namespaceImport.symbols

@@ -0,0 +1,42 @@
+=== /a.ts ===
+export class A { a!: string }
+>A : Symbol(A, Decl(a.ts, 0, 0))
+>a : Symbol(A.a, Decl(a.ts, 0, 16))
+
+export class B { b!: number }
+>B : Symbol(B, Decl(a.ts, 0, 29))
+>b : Symbol(B.b, Decl(a.ts, 1, 16))
+
+export type C<T> = T;
+>C : Symbol(C, Decl(a.ts, 1, 29))
+>T : Symbol(T, Decl(a.ts, 2, 14))
+>T : Symbol(T, Decl(a.ts, 2, 14))
+
+export const Value = {};
+>Value : Symbol(Value, Decl(a.ts, 3, 12))
+
+=== /b.ts ===
+import type * as types from './a';
+>types : Symbol(types, Decl(b.ts, 0, 11))
+
+types;
+types.Value;
+let v: types.Value;
+>v : Symbol(v, Decl(b.ts, 3, 3))
+>types : Symbol(types, Decl(b.ts, 0, 11))
+
+const a: types.A = {};
+>a : Symbol(a, Decl(b.ts, 4, 5))
+>types : Symbol(types, Decl(b.ts, 0, 11))
+>A : Symbol(types.A)
+
+const b: types.B = {};
+>b : Symbol(b, Decl(b.ts, 5, 5))
+>types : Symbol(types, Decl(b.ts, 0, 11))
+>B : Symbol(types.B)
+
+const c: types.C<string> = "";
+>c : Symbol(c, Decl(b.ts, 6, 5))
+>types : Symbol(types, Decl(b.ts, 0, 11))
+>C : Symbol(types.C, Decl(a.ts, 1, 29))
+

tests/baselines/reference/importClause_namespaceImport.types

@@ -0,0 +1,47 @@
+=== /a.ts ===
+export class A { a!: string }
+>A : A
+>a : string
+
+export class B { b!: number }
+>B : B
+>b : number
+
+export type C<T> = T;
+>C : T
+
+export const Value = {};
+>Value : {}
+>{} : {}
+
+=== /b.ts ===
+import type * as types from './a';
+>types : any
+
+types;
+>types : any
+
+types.Value;
+>types.Value : any
+>types : any
+>Value : any
+
+let v: types.Value;
+>v : any
+>types : any
+
+const a: types.A = {};
+>a : import("/a").A
+>types : any
+>{} : {}
+
+const b: types.B = {};
+>b : import("/a").B
+>types : any
+>{} : {}
+
+const c: types.C<string> = "";
+>c : string
+>types : any
+>"" : ""
+

tests/cases/conformance/externalModules/typeOnly/importClause_namespaceImport.ts

@@ -0,0 +1,14 @@
+// @Filename: /a.ts
+export class A { a!: string }
+export class B { b!: number }
+export type C<T> = T;
+export const Value = {};
+
+// @Filename: /b.ts
+import type * as types from './a';
+types;
+types.Value;
+let v: types.Value;
+const a: types.A = {};
+const b: types.B = {};
+const c: types.C<string> = "";