refactor: update prerender utils to work with TS 3.9

TypeScript 3.9 changed the way exports/imports work, by making them readonly in conformance with ES2015 spec. This, however breaks `spyOn`

Author: alan-agius4

modules/builders/src/prerender/index.ts

@@ -70,7 +70,7 @@ async function _parallelRenderRoutes(
   outputPath: string,
   indexFile: string,
   serverBundlePath: string,
-  ): Promise<void> {
+): Promise<void> {
   const workerFile = path.join(__dirname, 'render.js');
   const childProcesses = shardedRoutes.map(routes =>
     new Promise((resolve, reject) => {
@@ -148,7 +148,13 @@ export async function execute(
   options: PrerenderBuilderOptions,
   context: BuilderContext
 ): Promise<PrerenderBuilderOutput> {
-  const routes = await getRoutes(options, context);
+  const browserTarget = targetFromTargetString(options.browserTarget);
+  const browserOptions =
+    await context.getTargetOptions(browserTarget) as unknown as BrowserBuilderOptions;
+  const tsConfigPath =
+    typeof browserOptions.tsConfig === 'string' ? browserOptions.tsConfig : undefined;
+
+  const routes = await getRoutes(options, tsConfigPath, context);
   if (!routes.length) {
     throw new Error(`Could not find any routes to prerender.`);
   }
@@ -159,10 +165,6 @@ export async function execute(
     return { success, error } as BuilderOutput;
   }
 
-  const browserTarget = targetFromTargetString(options.browserTarget);
-  const browserOptions =
-      await context.getTargetOptions(browserTarget) as unknown as BrowserBuilderOptions;
-
   return _renderUniversal(
     routes,
     context,

modules/builders/src/prerender/utils.spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import * as Architect from '@angular-devkit/architect';
+import { BuilderContext } from '@angular-devkit/architect';
 import { BrowserBuilderOptions } from '@angular-devkit/build-angular';
 import { logging } from '@angular-devkit/core';
 import * as fs from 'fs';
@@ -28,18 +28,17 @@ describe('Prerender Builder Utils', () => {
       { path: '/user/:id' },
     ];
 
+    const TSCONFIG_PATH = 'tsconfig.app.json';
     const CONTEXT = {
       workspaceRoot: '/path/to/angular/json',
-      getTargetOptions: () => ({ tsConfig: 'tsconfig.app.json' }),
       logger: new logging.NullLogger(),
-    } as unknown as Architect.BuilderContext;
+    } as unknown as BuilderContext;
 
     let parseAngularRoutesSpy: jasmine.Spy;
     let loggerErrorSpy: jasmine.Spy;
 
     beforeEach(() => {
       spyOn(fs, 'readFileSync').and.returnValue(ROUTES_FILE_CONTENT);
-      spyOn(Architect, 'targetFromTargetString').and.returnValue({} as Architect.Target);
       parseAngularRoutesSpy = spyOn(guessParser, 'parseAngularRoutes')
         .and.returnValue(GUESSED_ROUTES);
       loggerErrorSpy = spyOn(CONTEXT.logger, 'error');
@@ -51,7 +50,7 @@ describe('Prerender Builder Utils', () => {
         routesFile: ROUTES_FILE,
         guessRoutes: true,
       } as PrerenderBuilderOptions;
-      const routes = await getRoutes(options, CONTEXT);
+      const routes = await getRoutes(options, TSCONFIG_PATH, CONTEXT);
       expect(routes).toEqual(
         jasmine.arrayContaining([
           '/route1',
@@ -65,7 +64,7 @@ describe('Prerender Builder Utils', () => {
 
     it('Should return only the given routes', async () => {
       const options = { routes: ROUTES } as PrerenderBuilderOptions;
-      const routes = await getRoutes(options, CONTEXT);
+      const routes = await getRoutes(options, TSCONFIG_PATH, CONTEXT);
       expect(routes).toEqual(jasmine.arrayContaining([
         '/route3',
         '/route4',
@@ -74,7 +73,7 @@ describe('Prerender Builder Utils', () => {
 
     it('Should return the routes from the routesFile', async () => {
       const options = { routesFile: ROUTES_FILE } as PrerenderBuilderOptions;
-      const routes = await getRoutes(options, CONTEXT);
+      const routes = await getRoutes(options, TSCONFIG_PATH, CONTEXT);
       expect(routes).toEqual(jasmine.arrayContaining([
         '/route1',
         '/route2',
@@ -85,7 +84,7 @@ describe('Prerender Builder Utils', () => {
     it('Should catch errors thrown by parseAngularRoutes', async () => {
       const options = { routes: ROUTES, guessRoutes: true } as PrerenderBuilderOptions;
       parseAngularRoutesSpy.and.throwError('Test Error');
-      const routes = await getRoutes(options, CONTEXT);
+      const routes = await getRoutes(options, TSCONFIG_PATH, CONTEXT);
       expect(routes).toEqual(jasmine.arrayContaining([
         '/route3',
         '/route4',

modules/builders/src/prerender/utils.ts

@@ -6,13 +6,12 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import { BuilderContext, targetFromTargetString } from '@angular-devkit/architect';
+import { BuilderContext } from '@angular-devkit/architect';
 import { BrowserBuilderOptions } from '@angular-devkit/build-angular';
 import * as fs from 'fs';
 import { parseAngularRoutes } from 'guess-parser';
 import * as os from 'os';
 import * as path from 'path';
-
 import { PrerenderBuilderOptions } from './models';
 
 /**
@@ -21,32 +20,29 @@ import { PrerenderBuilderOptions } from './models';
  */
 export async function getRoutes(
   options: PrerenderBuilderOptions,
+  tsConfigPath: string | undefined,
   context: BuilderContext,
 ): Promise<string[]> {
   let routes = options.routes || [];
-
+  const { logger, workspaceRoot } = context;
   if (options.routesFile) {
-    const routesFilePath = path.resolve(context.workspaceRoot, options.routesFile);
+    const routesFilePath = path.join(workspaceRoot, options.routesFile);
     routes = routes.concat(
       fs.readFileSync(routesFilePath, 'utf8')
         .split(/\r?\n/)
         .filter(v => !!v)
     );
   }
 
-  if (options.guessRoutes) {
-    const browserTarget = targetFromTargetString(options.browserTarget);
-    const { tsConfig } = await context.getTargetOptions(browserTarget);
-    if (typeof tsConfig === 'string') {
-      try {
-        routes = routes.concat(
-          parseAngularRoutes(path.join(context.workspaceRoot, tsConfig))
-            .map(routeObj => routeObj.path)
-            .filter(route => !route.includes('*') && !route.includes(':'))
-        );
-      } catch (e) {
-        context.logger.error('Unable to extract routes from application.', e);
-      }
+  if (options.guessRoutes && tsConfigPath) {
+    try {
+      routes = routes.concat(
+        parseAngularRoutes(path.join(workspaceRoot, tsConfigPath))
+          .map(routeObj => routeObj.path)
+          .filter(route => !route.includes('*') && !route.includes(':'))
+      );
+    } catch (e) {
+      logger.error('Unable to extract routes from application.', e);
     }
   }