fix(compiler-cli): attach the correct viaModule to namespace imports

packages/compiler-cli/ngcc/test/host/esm2015_host_spec.ts

@@ -1558,7 +1558,7 @@ runInEachFileSystem(() => {
         const actualDeclaration = host.getDeclarationOfIdentifier(identifier);
         expect(actualDeclaration).not.toBe(null);
         expect(actualDeclaration !.node).toBe(expectedDeclarationNode);
-        expect(actualDeclaration !.viaModule).toBe(null);
+        expect(actualDeclaration !.viaModule).toBe('@angular/core');
       });
 
       it('should return the original declaration of an aliased class', () => {

packages/compiler-cli/ngcc/test/host/esm5_host_spec.ts

@@ -1788,7 +1788,7 @@ runInEachFileSystem(() => {
         const actualDeclaration = host.getDeclarationOfIdentifier(identifier);
         expect(actualDeclaration).not.toBe(null);
         expect(actualDeclaration !.node).toBe(expectedDeclarationNode);
-        expect(actualDeclaration !.viaModule).toBe(null);
+        expect(actualDeclaration !.viaModule).toBe('@angular/core');
       });
 
       it('should return the correct declaration for an inner function identifier inside an ES5 IIFE',

packages/compiler-cli/src/ngtsc/reflection/src/typescript.ts

@@ -191,28 +191,21 @@ export class TypeScriptReflectionHost implements ReflectionHost {
       return null;
     }
 
-    // Ignore decorators that are defined locally (not imported).
     const decl: ts.Declaration = symbol.declarations[0];
-    if (!ts.isImportSpecifier(decl)) {
+    const importDecl = getContainingImportDeclaration(decl);
+
+    // Ignore declarations that are defined locally (not imported).
+    if (importDecl === null) {
       return null;
     }
 
-    // Walk back from the specifier to find the declaration, which carries the module specifier.
-    const importDecl = decl.parent !.parent !.parent !;
-
     // The module specifier is guaranteed to be a string literal, so this should always pass.
     if (!ts.isStringLiteral(importDecl.moduleSpecifier)) {
       // Not allowed to happen in TypeScript ASTs.
       return null;
     }
 
-    // Read the module specifier.
-    const from = importDecl.moduleSpecifier.text;
-
-    // Compute the name by which the decorator was exported, not imported.
-    const name = (decl.propertyName !== undefined ? decl.propertyName : decl.name).text;
-
-    return {from, name};
+    return {from: importDecl.moduleSpecifier.text, name: getExportedName(decl, id)};
   }
 
   /**
@@ -549,3 +542,23 @@ function getFarLeftIdentifier(propertyAccess: ts.PropertyAccessExpression): ts.I
   }
   return ts.isIdentifier(propertyAccess.expression) ? propertyAccess.expression : null;
 }
+
+/**
+ * Return the ImportDeclaration for the given `node` if it is either an `ImportSpecifier` or a
+ * `NamespaceImport`. If not return `null`.
+ */
+function getContainingImportDeclaration(node: ts.Node): ts.ImportDeclaration|null {
+  return ts.isImportSpecifier(node) ? node.parent !.parent !.parent ! :
+                                      ts.isNamespaceImport(node) ? node.parent.parent : null;
+}
+
+/**
+ * Compute the name by which the `decl` was exported, not imported.
+ * If no such declaration can be found (e.g. it is a namespace import)
+ * then fallback to the `originalId`.
+ */
+function getExportedName(decl: ts.Declaration, originalId: ts.Identifier): string {
+  return ts.isImportSpecifier(decl) ?
+      (decl.propertyName !== undefined ? decl.propertyName : decl.name).text :
+      originalId.text;
+}

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -1737,6 +1737,41 @@ runInEachFileSystem(os => {
                 'i0.ɵɵNgModuleDefWithMeta<TestModule, never, [typeof i1.InternalRouterModule], never>');
       });
 
+      it('should extract the generic type if it is provided as qualified type name from another package',
+         () => {
+           env.write(`test.ts`, `
+            import {NgModule} from '@angular/core';
+            import {RouterModule} from 'router';
+
+            @NgModule({imports: [RouterModule.forRoot()]})
+            export class TestModule {}`);
+
+           env.write('node_modules/router/index.d.ts', `
+            import {ModuleWithProviders} from '@angular/core';
+            import * as router2 from 'router2';
+
+            declare export class RouterModule {
+              static forRoot(): ModuleWithProviders<router2.Router2Module>;
+            }`);
+
+           env.write('node_modules/router2/index.d.ts', `
+            import {ɵɵNgModuleDefWithMeta} from '@angular/core';
+            export declare class Router2Module {
+              static ɵmod: ɵɵNgModuleDefWithMeta<Router2Module, never, never, never>;
+            }`);
+
+           env.driveMain();
+
+           const jsContents = env.getContents('test.js');
+           expect(jsContents).toContain('imports: [[RouterModule.forRoot()]]');
+
+           const dtsContents = env.getContents('test.d.ts');
+           expect(dtsContents).toContain(`import * as i1 from "router2";`);
+           expect(dtsContents)
+               .toContain(
+                   'i0.ɵɵNgModuleDefWithMeta<TestModule, never, [typeof i1.Router2Module], never>');
+         });
+
       it('should not reference a constant with a ModuleWithProviders value in module def imports',
          () => {
            env.write('dep.d.ts', `