Handle path mappings in Nx monorepos (#300)

* Handle path mappings in Nx monorepos

* Rename the import cache to prevent shadowing

packages/guess-parser/src/angular/index.ts

@@ -21,20 +21,20 @@ const imports = (
   child: string,
   program: ts.Program,
   host: ts.CompilerHost,
-  cache: {[parent: string]: {[child: string]: boolean}},
+  importCache: {[parent: string]: {[child: string]: boolean}},
   visited: { [key: string]: boolean } = {}
 ) => {
-  if (cache[parent] && cache[parent][child] !== undefined) {
-    return cache[parent][child];
+  if (importCache[parent] && importCache[parent][child] !== undefined) {
+    return importCache[parent][child];
   }
-  cache[parent] = cache[parent] || {};
+  importCache[parent] = importCache[parent] || {};
   const sf = program.getSourceFile(parent);
   if (!sf) {
-    cache[parent][child] = false;
+    importCache[parent][child] = false;
     return false;
   }
   if (visited[parent]) {
-    cache[parent][child] = false;
+    importCache[parent][child] = false;
     return false;
   }
   visited[parent] = true;
@@ -58,10 +58,10 @@ const imports = (
     }
     // We don't want to dig into node_modules to find an entry point.
     if (!found && existsSync(fullPath) && !fullPath.includes('node_modules')) {
-      found = imports(fullPath, child, program, host, cache, visited);
+      found = imports(fullPath, child, program, host, importCache, visited);
     }
   });
-  cache[parent][child] = found;
+  importCache[parent][child] = found;
   return found;
 };
 
@@ -194,13 +194,15 @@ const readChildren = (
   return null;
 };
 
-const getModulePathFromRoute = (parentPath: string, loadChildren: string) => {
-  const childModule = loadChildren.split('#')[0] + '.ts';
-  if (loadChildren.startsWith('.')) {
-    return join(dirname(parentPath), childModule);
+const getModulePathFromRoute = (parentPath: string, loadChildren: string, program: ts.Program, host: ts.CompilerHost) => {
+  const childModule = loadChildren.split('#')[0];
+  const { resolvedModule } = ts.resolveModuleName(childModule, parentPath, program.getCompilerOptions(), host);
+  if (resolvedModule) {
+    return resolvedModule.resolvedFileName;
   }
+  const childModuleFile = childModule + '.ts';
   const parentSegments = dirname(parentPath).split(sep);
-  const childSegments = childModule.split('/');
+  const childSegments = childModuleFile.split('/');
   const max = Math.min(parentSegments.length, childSegments.length);
   let maxCommon = 0;
   for (let i = 1; i < max; i += 1) {
@@ -218,7 +220,7 @@ const getModulePathFromRoute = (parentPath: string, loadChildren: string) => {
   }
   return join(
     dirname(parentPath),
-    childModule
+    childModuleFile
       .split('/')
       .slice(maxCommon, childSegments.length)
       .join('/')
@@ -269,7 +271,7 @@ const getRoute = (
       program,
       host
     );
-    const module = getModulePathFromRoute(parent, loadChildren);
+    const module = getModulePathFromRoute(parent, loadChildren, program, host);
     return {
       ...route,
       module
@@ -422,15 +424,16 @@ const findMainModule = (program: ts.Program) => {
 
 const getLazyEntryPoints = (
   node: ts.ObjectLiteralExpression,
-  program: ts.Program
+  program: ts.Program,
+  host: ts.CompilerHost
 ) => {
   const value = readLoadChildren(node, program.getTypeChecker());
   if (!value) {
     return null;
   }
 
   const parent = resolve(node.getSourceFile().fileName);
-  const module = getModulePathFromRoute(parent, value);
+  const module = getModulePathFromRoute(parent, value, program, host);
   return module;
 };
 
@@ -492,7 +495,8 @@ export const parseRoutes = (
       visitNode.bind(null, s, (n: ts.Node) => {
         const path = getLazyEntryPoints(
           n as ts.ObjectLiteralExpression,
-          program
+          program,
+          host
         );
         if (!path) {
           return;

packages/guess-parser/test/angular.spec.ts

@@ -1,6 +1,6 @@
 import { parseRoutes } from '../src/angular';
 
-const fixtureRoutes = new Set<string>([
+const fixtureRoutes = new Set([
   '/foo',
   '/foo/baz',
   '/foo/index',
@@ -11,26 +11,46 @@ const fixtureRoutes = new Set<string>([
   '/bar-simple'
 ]);
 
+const nxRoutes = new Set([
+  '/login',
+  '/home',
+  '/customers/list',
+  '/customers'
+]);
+
 describe('Angular parser', () => {
   it('should parse an app', () => {
     expect(() =>
-      parseRoutes('packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json')
+      parseRoutes(
+        'packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json'
+      )
     ).not.toThrow();
   });
 
   it('should produce routes', () => {
-    const routes = parseRoutes('packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json');
+    const routes = parseRoutes(
+      'packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json'
+    );
     expect(routes instanceof Array).toBeTruthy();
     const allRoutes = new Set(routes.map(r => r.path));
     [...allRoutes].forEach(r => expect(fixtureRoutes).toContain(r));
     expect(allRoutes.size).toEqual(fixtureRoutes.size);
   });
 
   it('should produce routes with proper paths', () => {
-    const routes = parseRoutes('packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json');
+    const routes = parseRoutes(
+      'packages/guess-parser/test/fixtures/angular/src/tsconfig.app.json'
+    );
     const route = routes.find(r => r.path === '/foo');
     expect(route!.modulePath.endsWith('foo.module.ts')).toBeTruthy();
     expect(route!.lazy).toBeTruthy();
     expect(route!.parentModulePath!.endsWith('app.module.ts')).toBeTruthy();
   });
+
+  it('should work with nx monorepo with path mappings', () => {
+    const routes = parseRoutes(
+      'packages/guess-parser/test/fixtures/nx/apps/ng-cli-app/tsconfig.app.json'
+    ).map(r => r.path);
+    [...routes].forEach(r => expect(nxRoutes).toContain(r));
+  });
 });

packages/guess-parser/test/fixtures/nx/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 Christian Janz
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/guess-parser/test/fixtures/nx/README.md

@@ -0,0 +1,3 @@
+# Angular monorepo example using Nx
+
+This app shows the process of refactoring an Angular app to a monorepo with the help of [Nx](https://nx.dev/angular)