fix(dev-infra): update the config file loading for ng-dev to expect js (#36918)

Migrating to a js file for providing a configuration allows for more
extensive configuration at run time.  This allows for configs to include
logic and move beyond static values found in JSON files.

PR Close #36918

dev-infra/utils/BUILD.bazel

@@ -9,10 +9,8 @@ ts_library(
     module_name = "@angular/dev-infra-private/utils",
     visibility = ["//dev-infra:__subpackages__"],
     deps = [
-        "@npm//@types/json5",
         "@npm//@types/node",
         "@npm//@types/shelljs",
-        "@npm//json5",
         "@npm//shelljs",
         "@npm//tslib",
     ],

dev-infra/utils/config.ts

@@ -5,11 +5,13 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import {readFileSync} from 'fs';
-import {parse} from 'json5';
+
 import {join} from 'path';
 import {exec} from 'shelljs';
 
+// The filename expected for creating the ng-dev config.
+const CONFIG_FILE_NAME = '.ng-dev-config.js';
+
 /**
  * Gets the path of the directory for the repository base.
  */
@@ -25,19 +27,18 @@ export function getRepoBaseDir() {
 }
 
 /**
- * Retrieve the configuration from the .dev-infra.json file.
+ * Retrieve the configuration from the .ng-dev-config.js file.
  */
-export function getAngularDevConfig<K, T>(): DevInfraConfig<K, T> {
-  const configPath = join(getRepoBaseDir(), '.dev-infra.json');
-  let rawConfig = '';
+export function getAngularDevConfig<K, T>(supressError = false): DevInfraConfig<K, T> {
+  const configPath = join(getRepoBaseDir(), CONFIG_FILE_NAME);
   try {
-    rawConfig = readFileSync(configPath, 'utf8');
-  } catch {
-    throw Error(
-        `Unable to find config file at:\n` +
-        `  ${configPath}`);
+    return require(configPath) as DevInfraConfig<K, T>;
+  } catch (err) {
+    if (!supressError) {
+      throw Error(`Unable to load config file at:\n  ${configPath}`);
     }
-  return parse(rawConfig);
+  }
+  return {} as DevInfraConfig<K, T>;
 }
 
 /**

package.json

@@ -153,7 +153,6 @@
     "@bazel/ibazel": "^0.12.3",
     "@octokit/graphql": "^4.3.1",
     "@types/cli-progress": "^3.4.2",
-    "@types/json5": "^0.0.30",
     "@types/minimist": "^1.2.0",
     "@yarnpkg/lockfile": "^1.1.0",
     "browserstacktunnel-wrapper": "2.0.1",
@@ -173,7 +172,6 @@
     "husky": "^4.2.3",
     "inquirer": "^7.1.0",
     "jpm": "1.3.1",
-    "json5": "^2.1.2",
     "karma-browserstack-launcher": "^1.3.0",
     "karma-sauce-launcher": "^2.0.2",
     "madge": "^3.6.0",

yarn.lock

@@ -1477,11 +1477,6 @@
   dependencies:
     "@types/jasmine" "*"
 
-"@types/json5@^0.0.30":
-  version "0.0.30"
-  resolved "https://registry.yarnpkg.com/@types/json5/-/json5-0.0.30.tgz#44cb52f32a809734ca562e685c6473b5754a7818"
-  integrity sha512-sqm9g7mHlPY/43fcSNrCYfOeX9zkTTK+euO5E6+CVijSMm5tTjkVdwdqRkY3ljjIAf8679vps5jKUoJBCLsMDA==
-
 "@types/long@^4.0.0":
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/@types/long/-/long-4.0.1.tgz#459c65fa1867dafe6a8f322c4c51695663cc55e9"