feat(bazel): provide the node loader to load esm files in jasmine tests (#3025)

PR Close #3025

Author: josephperrott

bazel/jasmine/jasmine.bzl

@@ -1,15 +1,22 @@
 load("@aspect_rules_jasmine//jasmine:defs.bzl", _jasmine_test = "jasmine_test")
 
-def jasmine_test(name, data = [], node_options = [], **kwargs):
+def jasmine_test(name, data = [], tsconfig = None, node_options = [], env = {}, **kwargs):
+    if tsconfig:
+        env = dict(env, **{
+            "NODE_OPTIONS_TSCONFIG_PATH": "$(rlocationpath %s)" % tsconfig,
+        })
+
     _jasmine_test(
         name = name,
         data = data + [
             "@devinfra//bazel/jasmine:stack-traces",
+            "@devinfra//bazel/private/node_loader:node_loader",
         ],
+        env = env,
         size = kwargs.pop("size", "medium"),
         node_options = [
-            "--import",
-            "$$JS_BINARY__RUNFILES/$(rlocationpath @devinfra//bazel/jasmine:stack-traces)",
+            "--import=$$JS_BINARY__RUNFILES/$(rlocationpath @devinfra//bazel/private/node_loader:node_loader)",
+            "--import=$$JS_BINARY__RUNFILES/$(rlocationpath @devinfra//bazel/jasmine:stack-traces)",
         ] + node_options,
         **kwargs
     )

bazel/package.json

@@ -12,6 +12,7 @@
     "@types/yargs": "17.0.33",
     "browser-sync": "3.0.4",
     "chalk": "5.6.0",
+    "get-tsconfig": "4.10.1",
     "piscina": "^5.0.0",
     "send": "1.2.0",
     "true-case-path": "2.2.1",

bazel/private/node_loader/BUILD.bazel

@@ -0,0 +1,15 @@
+load("@aspect_rules_js//js:defs.bzl", "js_library")
+
+js_library(
+    name = "node_loader_lib",
+    srcs = ["hooks.mjs"],
+    visibility = ["//visibility:public"],
+    deps = ["//bazel:node_modules/get-tsconfig"],
+)
+
+js_library(
+    name = "node_loader",
+    srcs = ["index.mjs"],
+    visibility = ["//visibility:public"],
+    deps = [":node_loader_lib"],
+)

bazel/private/node_loader/hooks.mjs

@@ -0,0 +1,75 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+/**
+ * @fileoverview
+ *
+ * Module loader that augments NodeJS's execution to:
+ *
+ * - support native execution of Angular JavaScript output
+ *   that isn't strict ESM at this point (lack of explicit extensions).
+ * - support path mappings at runtime. This allows us to natively execute ESM
+ *   without having to pre-bundle for testing, or use the slow full npm linked packages
+ */
+
+import {parseTsconfig, createPathsMatcher} from 'get-tsconfig';
+
+import path from 'node:path';
+
+const explicitExtensionRe = /\.[mc]?js$/;
+const nonModuleImportRe = /^[.\/]/;
+
+const runfilesRoot = process.env.JS_BINARY__RUNFILES;
+const tsconfigPath = process.env.NODE_OPTIONS_TSCONFIG_PATH;
+
+let pathMappingMatcher;
+// When no tsconfig is provided no match can be generated so we always return an empty list.
+if (tsconfigPath === undefined) {
+  pathMappingMatcher = () => [];
+} else {
+  const tsconfigFullPath = path.join(runfilesRoot, tsconfigPath);
+  const tsconfig = parseTsconfig(tsconfigFullPath);
+  pathMappingMatcher = createPathsMatcher({config: tsconfig, path: tsconfigFullPath});
+}
+
+/** @type {import('module').ResolveHook} */
+export const resolve = async (specifier, context, nextResolve) => {
+  // True when it's a non-module import without explicit extensions.
+  const isNonModuleExtensionlessImport =
+    nonModuleImportRe.test(specifier) && !explicitExtensionRe.test(specifier);
+  const pathMappings = !nonModuleImportRe.test(specifier) ? pathMappingMatcher(specifier) : [];
+
+  // If it's neither path mapped, nor an extension-less import that may be fixed up, exit early.
+  if (!isNonModuleExtensionlessImport && pathMappings.length === 0) {
+    return nextResolve(specifier, context);
+  }
+
+  if (pathMappings.length > 0) {
+    for (const mapping of pathMappings) {
+      const res = await resolve(mapping, context, nextResolve).catch(() => null);
+      if (res !== null) {
+        return res;
+      }
+    }
+  } else {
+    const specifiers = [
+      `${specifier}.js`,
+      `${specifier}/index.js`,
+      // Legacy variants for the `zone.js` variant using still `ts_library`.
+      // TODO(rules_js migration): Remove this.
+      `${specifier}.mjs`,
+      `${specifier}/index.mjs`,
+    ];
+    for (const specifier of specifiers) {
+      try {
+        return await nextResolve(specifier, context);
+      } catch {}
+    }
+  }
+  return nextResolve(specifier, context);
+};

bazel/private/node_loader/index.mjs

@@ -0,0 +1,11 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import {register} from 'node:module';
+
+register('./hooks.mjs', {parentURL: import.meta.url});