Allow referencing type-only exports as namespace members in ImportTypes and TypeQueries (microsoft#49056)

* Allow referencing type-only exports as namespace members in ImportTypes and TypeQueries

* Add extra test case

* ;; -> ;

* undefined -> false

Co-authored-by: Daniel Rosenwasser <[email protected]>

Author: andrewbranch

src/compiler/checker.ts

@@ -4110,8 +4110,10 @@ namespace ts {
             return getMergedSymbol(symbol && (symbol.flags & SymbolFlags.ExportValue) !== 0 && symbol.exportSymbol || symbol);
         }
 
-        function symbolIsValue(symbol: Symbol): boolean {
-            return !!(symbol.flags & SymbolFlags.Value || symbol.flags & SymbolFlags.Alias && resolveAlias(symbol).flags & SymbolFlags.Value && !getTypeOnlyAliasDeclaration(symbol));
+        function symbolIsValue(symbol: Symbol, includeTypeOnlyMembers?: boolean): boolean {
+            return !!(
+                symbol.flags & SymbolFlags.Value ||
+                symbol.flags & SymbolFlags.Alias && resolveAlias(symbol).flags & SymbolFlags.Value && (includeTypeOnlyMembers || !getTypeOnlyAliasDeclaration(symbol)));
         }
 
         function findConstructorDeclaration(node: ClassLikeDeclaration): ConstructorDeclaration | undefined {
@@ -12575,12 +12577,12 @@ namespace ts {
          * @param type a type to look up property from
          * @param name a name of property to look up in a given type
          */
-        function getPropertyOfType(type: Type, name: __String, skipObjectFunctionPropertyAugment?: boolean): Symbol | undefined {
+        function getPropertyOfType(type: Type, name: __String, skipObjectFunctionPropertyAugment?: boolean, includeTypeOnlyMembers?: boolean): Symbol | undefined {
             type = getReducedApparentType(type);
             if (type.flags & TypeFlags.Object) {
                 const resolved = resolveStructuredTypeMembers(type as ObjectType);
                 const symbol = resolved.members.get(name);
-                if (symbol && symbolIsValue(symbol)) {
+                if (symbol && symbolIsValue(symbol, includeTypeOnlyMembers)) {
                     return symbol;
                 }
                 if (skipObjectFunctionPropertyAugment) return undefined;
@@ -16208,7 +16210,7 @@ namespace ts {
                         // the `exports` lookup process that only looks up namespace members which is used for most type references
                         const mergedResolvedSymbol = getMergedSymbol(resolveSymbol(currentNamespace));
                         const next = node.isTypeOf
-                            ? getPropertyOfType(getTypeOfSymbol(mergedResolvedSymbol), current.escapedText)
+                            ? getPropertyOfType(getTypeOfSymbol(mergedResolvedSymbol), current.escapedText, /*skipObjectFunctionPropertyAugment*/ false, /*includeTypeOnlyMembers*/ true)
                             : getSymbol(getExportsOfSymbol(mergedResolvedSymbol), current.escapedText, meaning);
                         if (!next) {
                             error(current, Diagnostics.Namespace_0_has_no_exported_member_1, getFullyQualifiedName(currentNamespace), declarationNameToString(current));
@@ -28995,9 +28997,9 @@ namespace ts {
                     if (isIdentifier(left) && parentSymbol) {
                         markAliasReferenced(parentSymbol, node);
                     }
-                    return isErrorType(apparentType) ? errorType : apparentType;;
+                    return isErrorType(apparentType) ? errorType : apparentType;
                 }
-                prop = getPropertyOfType(apparentType, right.escapedText);
+                prop = getPropertyOfType(apparentType, right.escapedText, /*skipObjectFunctionPropertyAugment*/ false, /*includeTypeOnlyMembers*/ node.kind === SyntaxKind.QualifiedName);
             }
             // In `Foo.Bar.Baz`, 'Foo' is not referenced if 'Bar' is a const enum or a module containing only const enums.
             // `Foo` is also not referenced in `enum FooCopy { Bar = Foo.Bar }`, because the enum member value gets inlined

tests/baselines/reference/namespaceImportTypeQuery.errors.txt

@@ -1,4 +1,5 @@
-/b.ts(2,21): error TS2339: Property 'A' does not exist on type 'typeof import("/a")'.
+/b.ts(8,3): error TS2322: Type '{ A: any; B: any; }' is not assignable to type 'typeof import("/a")'.
+  Object literal may only specify known properties, and 'A' does not exist in type 'typeof import("/a")'.
 
 
 ==== /a.ts (0 errors) ====
@@ -9,7 +10,15 @@
 ==== /b.ts (1 errors) ====
     import * as types from './a';
     let A: typeof types.A;
-                        ~
-!!! error TS2339: Property 'A' does not exist on type 'typeof import("/a")'.
     let B: typeof types.B;
+    
+    let t: typeof types = {
+      // error: while you can ask for `typeof types.A`,
+      // `typeof types` does not include `A`
+      A: undefined as any,
+      ~~~~~~~~~~~~~~~~~~~
+!!! error TS2322: Type '{ A: any; B: any; }' is not assignable to type 'typeof import("/a")'.
+!!! error TS2322:   Object literal may only specify known properties, and 'A' does not exist in type 'typeof import("/a")'.
+      B: undefined as any,
+    }
 

tests/baselines/reference/namespaceImportTypeQuery.js

@@ -9,6 +9,13 @@ export class B {};
 import * as types from './a';
 let A: typeof types.A;
 let B: typeof types.B;
+
+let t: typeof types = {
+  // error: while you can ask for `typeof types.A`,
+  // `typeof types` does not include `A`
+  A: undefined as any,
+  B: undefined as any,
+}
 
 
 //// [a.js]
@@ -32,3 +39,9 @@ exports.B = B;
 exports.__esModule = true;
 var A;
 var B;
+var t = {
+    // error: while you can ask for `typeof types.A`,
+    // `typeof types` does not include `A`
+    A: undefined,
+    B: undefined
+};

tests/baselines/reference/namespaceImportTypeQuery.symbols

@@ -14,11 +14,28 @@ import * as types from './a';
 
 let A: typeof types.A;
 >A : Symbol(A, Decl(b.ts, 1, 3))
+>types.A : Symbol(types.A, Decl(a.ts, 1, 13))
 >types : Symbol(types, Decl(b.ts, 0, 6))
+>A : Symbol(types.A, Decl(a.ts, 1, 13))
 
 let B: typeof types.B;
 >B : Symbol(B, Decl(b.ts, 2, 3))
 >types.B : Symbol(types.B, Decl(a.ts, 1, 18))
 >types : Symbol(types, Decl(b.ts, 0, 6))
 >B : Symbol(types.B, Decl(a.ts, 1, 18))
 
+let t: typeof types = {
+>t : Symbol(t, Decl(b.ts, 4, 3))
+>types : Symbol(types, Decl(b.ts, 0, 6))
+
+  // error: while you can ask for `typeof types.A`,
+  // `typeof types` does not include `A`
+  A: undefined as any,
+>A : Symbol(A, Decl(b.ts, 4, 23))
+>undefined : Symbol(undefined)
+
+  B: undefined as any,
+>B : Symbol(B, Decl(b.ts, 7, 22))
+>undefined : Symbol(undefined)
+}
+

tests/baselines/reference/namespaceImportTypeQuery.types

@@ -13,14 +13,32 @@ import * as types from './a';
 >types : typeof types
 
 let A: typeof types.A;
->A : any
->types.A : any
+>A : typeof types.A
+>types.A : typeof types.A
 >types : typeof types
->A : any
+>A : typeof types.A
 
 let B: typeof types.B;
 >B : typeof types.B
 >types.B : typeof types.B
 >types : typeof types
 >B : typeof types.B
 
+let t: typeof types = {
+>t : typeof types
+>types : typeof types
+>{  // error: while you can ask for `typeof types.A`,  // `typeof types` does not include `A`  A: undefined as any,  B: undefined as any,} : { A: any; B: any; }
+
+  // error: while you can ask for `typeof types.A`,
+  // `typeof types` does not include `A`
+  A: undefined as any,
+>A : any
+>undefined as any : any
+>undefined : undefined
+
+  B: undefined as any,
+>B : any
+>undefined as any : any
+>undefined : undefined
+}
+

tests/baselines/reference/typeofImportTypeOnlyExport.js

@@ -0,0 +1,58 @@
+//// [tests/cases/conformance/declarationEmit/typeofImportTypeOnlyExport.ts] ////
+
+//// [button.ts]
+import {classMap} from './lit.js';
+export const c = classMap();
+
+//// [lit.ts]
+class ClassMapDirective {}
+
+export type {ClassMapDirective};
+
+export const directive =
+  <C>(class_: C) =>
+  () => ({
+    directive: class_,
+  });
+
+export const classMap = directive(ClassMapDirective);
+
+
+//// [lit.js]
+"use strict";
+exports.__esModule = true;
+exports.classMap = exports.directive = void 0;
+var ClassMapDirective = /** @class */ (function () {
+    function ClassMapDirective() {
+    }
+    return ClassMapDirective;
+}());
+var directive = function (class_) {
+    return function () { return ({
+        directive: class_
+    }); };
+};
+exports.directive = directive;
+exports.classMap = (0, exports.directive)(ClassMapDirective);
+//// [button.js]
+"use strict";
+exports.__esModule = true;
+exports.c = void 0;
+var lit_js_1 = require("./lit.js");
+exports.c = (0, lit_js_1.classMap)();
+
+
+//// [lit.d.ts]
+declare class ClassMapDirective {
+}
+export type { ClassMapDirective };
+export declare const directive: <C>(class_: C) => () => {
+    directive: C;
+};
+export declare const classMap: () => {
+    directive: typeof ClassMapDirective;
+};
+//// [button.d.ts]
+export declare const c: {
+    directive: typeof import("./lit.js").ClassMapDirective;
+};

tests/baselines/reference/typeofImportTypeOnlyExport.symbols

@@ -0,0 +1,35 @@
+=== tests/cases/conformance/declarationEmit/button.ts ===
+import {classMap} from './lit.js';
+>classMap : Symbol(classMap, Decl(button.ts, 0, 8))
+
+export const c = classMap();
+>c : Symbol(c, Decl(button.ts, 1, 12))
+>classMap : Symbol(classMap, Decl(button.ts, 0, 8))
+
+=== tests/cases/conformance/declarationEmit/lit.ts ===
+class ClassMapDirective {}
+>ClassMapDirective : Symbol(ClassMapDirective, Decl(lit.ts, 0, 0))
+
+export type {ClassMapDirective};
+>ClassMapDirective : Symbol(ClassMapDirective, Decl(lit.ts, 2, 13))
+
+export const directive =
+>directive : Symbol(directive, Decl(lit.ts, 4, 12))
+
+  <C>(class_: C) =>
+>C : Symbol(C, Decl(lit.ts, 5, 3))
+>class_ : Symbol(class_, Decl(lit.ts, 5, 6))
+>C : Symbol(C, Decl(lit.ts, 5, 3))
+
+  () => ({
+    directive: class_,
+>directive : Symbol(directive, Decl(lit.ts, 6, 10))
+>class_ : Symbol(class_, Decl(lit.ts, 5, 6))
+
+  });
+
+export const classMap = directive(ClassMapDirective);
+>classMap : Symbol(classMap, Decl(lit.ts, 10, 12))
+>directive : Symbol(directive, Decl(lit.ts, 4, 12))
+>ClassMapDirective : Symbol(ClassMapDirective, Decl(lit.ts, 0, 0))
+

tests/baselines/reference/typeofImportTypeOnlyExport.types

@@ -0,0 +1,40 @@
+=== tests/cases/conformance/declarationEmit/button.ts ===
+import {classMap} from './lit.js';
+>classMap : () => { directive: typeof import("tests/cases/conformance/declarationEmit/lit").ClassMapDirective; }
+
+export const c = classMap();
+>c : { directive: typeof import("tests/cases/conformance/declarationEmit/lit").ClassMapDirective; }
+>classMap() : { directive: typeof import("tests/cases/conformance/declarationEmit/lit").ClassMapDirective; }
+>classMap : () => { directive: typeof import("tests/cases/conformance/declarationEmit/lit").ClassMapDirective; }
+
+=== tests/cases/conformance/declarationEmit/lit.ts ===
+class ClassMapDirective {}
+>ClassMapDirective : ClassMapDirective
+
+export type {ClassMapDirective};
+>ClassMapDirective : ClassMapDirective
+
+export const directive =
+>directive : <C>(class_: C) => () => { directive: C; }
+
+  <C>(class_: C) =>
+><C>(class_: C) =>  () => ({    directive: class_,  }) : <C>(class_: C) => () => { directive: C; }
+>class_ : C
+
+  () => ({
+>() => ({    directive: class_,  }) : () => { directive: C; }
+>({    directive: class_,  }) : { directive: C; }
+>{    directive: class_,  } : { directive: C; }
+
+    directive: class_,
+>directive : C
+>class_ : C
+
+  });
+
+export const classMap = directive(ClassMapDirective);
+>classMap : () => { directive: typeof ClassMapDirective; }
+>directive(ClassMapDirective) : () => { directive: typeof ClassMapDirective; }
+>directive : <C>(class_: C) => () => { directive: C; }
+>ClassMapDirective : typeof ClassMapDirective
+

tests/cases/conformance/declarationEmit/typeofImportTypeOnlyExport.ts

@@ -0,0 +1,18 @@
+// @declaration: true
+
+// @Filename: button.ts
+import {classMap} from './lit.js';
+export const c = classMap();
+
+// @Filename: lit.ts
+class ClassMapDirective {}
+
+export type {ClassMapDirective};
+
+export const directive =
+  <C>(class_: C) =>
+  () => ({
+    directive: class_,
+  });
+
+export const classMap = directive(ClassMapDirective);

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

@@ -7,3 +7,10 @@ export class B {};
 import * as types from './a';
 let A: typeof types.A;
 let B: typeof types.B;
+
+let t: typeof types = {
+  // error: while you can ask for `typeof types.A`,
+  // `typeof types` does not include `A`
+  A: undefined as any,
+  B: undefined as any,
+}