feat(@nguniversal/builders): add support for proxy configuration in s…

…sr-dev-server

With this change we added a new `proxyConfig` option to be used to provide custom proxy configurations to the ssr-dev-server builder.

Closes #1757

modules/builders/src/ssr-dev-server/index.spec.ts

@@ -8,6 +8,7 @@
 
 import { Architect, BuilderRun } from '@angular-devkit/architect';
 import * as browserSync from 'browser-sync';
+import * as http from 'http';
 import * as https from 'https';
 import { from, throwError, timer } from 'rxjs';
 import { concatMap, debounceTime, mergeMap, retryWhen, take } from 'rxjs/operators';
@@ -137,4 +138,37 @@ describe('Serve SSR Builder', () => {
       )
       .toPromise();
   });
+
+  it('proxies requests based on the proxy configuration file provided in the option', async () => {
+    const proxyServer = http.createServer((request, response) => {
+      if (request.url?.endsWith('/test')) {
+        response.writeHead(200);
+        response.end('TEST_API_RETURN');
+      } else {
+        response.writeHead(404);
+        response.end();
+      }
+    });
+
+    try {
+      await new Promise<void>(resolve => proxyServer.listen(0, '127.0.0.1', resolve));
+      const proxyAddress = proxyServer.address() as import('net').AddressInfo;
+
+      host.writeMultipleFiles({
+        'proxy.config.json': `{ "/api/*": { "logLevel": "debug","target": "http://127.0.0.1:${proxyAddress.port}" } }`,
+      });
+
+      const run = await architect.scheduleTarget(target, { port: 7001, proxyConfig: 'proxy.config.json' });
+      runs.push(run);
+
+      const output = await run.result as SSRDevServerBuilderOutput;
+      expect(output.success).toBe(true);
+      expect(output.baseUrl).toBe('http://localhost:7001');
+      const response = await fetch('http://localhost:7001/api/test');
+      expect(await response?.text()).toContain('TEST_API_RETURN');
+
+    } finally {
+      await new Promise<void>((resolve) => proxyServer.close(() => resolve()));
+    }
+  });
 });

modules/builders/src/ssr-dev-server/index.ts

@@ -14,6 +14,7 @@ import {
 } from '@angular-devkit/architect';
 import { json, logging, tags } from '@angular-devkit/core';
 import * as browserSync from 'browser-sync';
+import { existsSync } from 'fs';
 import { createProxyMiddleware } from 'http-proxy-middleware';
 import { join, resolve as pathResolve } from 'path';
 import {
@@ -212,7 +213,7 @@ async function initBrowserSync(
     return browserSyncInstance;
   }
 
-  const { port: browserSyncPort, open, host, publicHost } = options;
+  const { port: browserSyncPort, open, host, publicHost, proxyConfig } = options;
   const bsPort = browserSyncPort || await getAvailablePort();
   const bsOptions: browserSync.Options = {
     proxy: {
@@ -284,6 +285,19 @@ async function initBrowserSync(
     }
   }
 
+  if (proxyConfig) {
+    if (!bsOptions.middleware) {
+      bsOptions.middleware = [];
+    } else if (!Array.isArray(bsOptions.middleware)) {
+      bsOptions.middleware = [bsOptions.middleware];
+    }
+
+    bsOptions.middleware = [
+      ...bsOptions.middleware,
+      ...getProxyConfig(context.workspaceRoot, proxyConfig),
+    ];
+  }
+
   return new Promise((resolve, reject) => {
     browserSyncInstance.init(bsOptions, (error, bs) => {
       if (error) {
@@ -322,4 +336,36 @@ function getSslConfig(
   return ssl;
 }
 
+function getProxyConfig(
+  root: string,
+  proxyConfig: string,
+): browserSync.MiddlewareHandler[] {
+  const proxyPath = pathResolve(root, proxyConfig);
+  let proxySettings: any;
+  try {
+    proxySettings = require(proxyPath);
+  } catch (error) {
+    if (error.code === 'MODULE_NOT_FOUND') {
+      throw new Error(`Proxy config file ${proxyPath} does not exist.`);
+    }
+
+    throw error;
+  }
+
+  const proxies = Array.isArray(proxySettings) ? proxySettings : [proxySettings];
+
+  return proxies.map(proxy => {
+    const keys = Object.keys(proxy);
+    const context = keys[0];
+
+    if (keys.length === 1 || typeof context === 'string') {
+      const normalizedContext = context.replace(/^\*$/, '**').replace(/\/\*$/, '');
+
+      return createProxyMiddleware(normalizedContext, proxy[context]) as any;
+    }
+
+    return createProxyMiddleware(proxy) as any;
+  });
+}
+
 export default createBuilder<SSRDevServerBuilderOptions, BuilderOutput>(execute);

modules/builders/src/ssr-dev-server/schema.json

@@ -55,6 +55,10 @@
     "sslCert": {
       "type": "string",
       "description": "SSL certificate to use for serving HTTPS."
+    },
+    "proxyConfig": {
+      "type": "string",
+      "description": "Proxy configuration file."
     }
   },
   "additionalProperties": false,

modules/builders/src/ssr-dev-server/schema.ts

@@ -42,4 +42,7 @@ export interface Schema {
 
   /** SSL certificate to use for serving HTTPS. */
   sslCert?: string;
+
+  /** Proxy configuration file */
+  proxyConfig?: string;
 }

tools/defaults.bzl

@@ -106,6 +106,7 @@ def jasmine_node_test(deps = [], **kwargs):
 
     _jasmine_node_test(
         deps = local_deps,
+        templated_args = ["--bazel_patch_module_resolver"],
         configuration_env_vars = ["compile"],
         **kwargs
     )