test: reset node environments after ts-node test (#17991)

* test: reset node environments after ts-node test

* Update packages/babel-core/test/config-ts-integration-ts-node.js

Co-authored-by: Nicolò Ribaudo <[email protected]>

---------

Co-authored-by: Nicolò Ribaudo <[email protected]>

packages/babel-core/package.json

@@ -62,6 +62,7 @@
     "@babel/plugin-transform-modules-commonjs": "workspace:^",
     "@babel/preset-env": "workspace:^",
     "@babel/preset-typescript": "workspace:^",
+    "@cspotcode/source-map-support": "^0.8.1",
     "@jridgewell/trace-mapping": "^0.3.28",
     "@types/convert-source-map": "^2.0.0",
     "@types/resolve": "^1.3.2",

packages/babel-core/test/config-ts-integration-ts-node.js

@@ -4,6 +4,131 @@ import { commonJS } from "$repo-utils";
 
 const { __dirname, require } = commonJS(import.meta.url);
 
+// Changes from https://github.com/TypeStrong/ts-node/blob/ddb05ef23be92a90c3ecac5a0220435c65ebbd2a/src/test/helpers/reset-node-environment.ts
+// - Removed type annotations
+// - Replaced lodash imports with native implementations
+// import { has, mapValues, sortBy } from 'lodash';
+
+const has = Object.hasOwn;
+const mapValues = (obj, callback) =>
+  Object.fromEntries(
+    Object.entries(obj).map(([key, value]) => [key, callback(value, key, obj)]),
+  );
+const sortBy = (array, callback) =>
+  array.toSorted((a, b) => Math.sign(callback(a) - callback(b)));
+
+// Reset node environment
+// Useful because ts-node installation necessarily must mutate the node environment.
+// Yet we want to run tests in-process for speed.
+// So we need to reliably reset everything changed by ts-node installation.
+
+const defaultRequireExtensions = captureObjectState(require.extensions);
+// Avoid node deprecation warning for accessing _channel
+const defaultProcess = captureObjectState(process, ["_channel"]);
+const defaultModule = captureObjectState(require("node:module"));
+const defaultError = captureObjectState(Error);
+const defaultGlobal = captureObjectState(global);
+
+/**
+ * Undo all of ts-node & co's installed hooks, resetting the node environment to default
+ * so we can run multiple test cases which `.register()` ts-node.
+ *
+ * Must also play nice with `nyc`'s environmental mutations.
+ */
+function resetNodeEnvironment() {
+  const sms = require("@cspotcode/source-map-support");
+  // We must uninstall so that it resets its internal state; otherwise it won't know it needs to reinstall in the next test.
+  sms.uninstall();
+  // Must remove handlers to avoid a memory leak
+  sms.resetRetrieveHandlers();
+
+  // Modified by ts-node hooks
+  resetObject(
+    require.extensions,
+    defaultRequireExtensions,
+    undefined,
+    undefined,
+    undefined,
+    true,
+  );
+
+  // ts-node attaches a property when it registers an instance
+  // source-map-support monkey-patches the emit function
+  // Avoid node deprecation warnings for setting process.config or accessing _channel
+  resetObject(process, defaultProcess, undefined, ["_channel"], ["config"]);
+
+  // source-map-support swaps out the prepareStackTrace function
+  resetObject(Error, defaultError);
+
+  // _resolveFilename et.al. are modified by ts-node, tsconfig-paths, source-map-support, yarn, maybe other things?
+  resetObject(require("node:module"), defaultModule, undefined, [
+    "wrap",
+    "wrapper",
+  ]);
+
+  // May be modified by REPL tests, since the REPL sets globals.
+  // Avoid deleting nyc's coverage data.
+  resetObject(global, defaultGlobal, ["__coverage__"]);
+
+  // Reset our ESM hooks
+  process.__test_setloader__?.(undefined);
+}
+
+function captureObjectState(object, avoidGetters = []) {
+  const descriptors = Object.getOwnPropertyDescriptors(object);
+  const values = mapValues(descriptors, (_d, key) => {
+    if (avoidGetters.includes(key)) return descriptors[key].value;
+    return object[key];
+  });
+  return {
+    descriptors,
+    values,
+  };
+}
+// Redefine all property descriptors and delete any new properties
+function resetObject(
+  object,
+  state,
+  doNotDeleteTheseKeys = [],
+  doNotSetTheseKeys = [],
+  avoidSetterIfUnchanged = [],
+  reorderProperties = false,
+) {
+  const currentDescriptors = Object.getOwnPropertyDescriptors(object);
+  for (const key of Object.keys(currentDescriptors)) {
+    if (doNotDeleteTheseKeys.includes(key)) continue;
+    if (has(state.descriptors, key)) continue;
+    delete object[key];
+  }
+  // Trigger nyc's setter functions
+  for (const [key, value] of Object.entries(state.values)) {
+    try {
+      if (doNotSetTheseKeys === true || doNotSetTheseKeys.includes(key))
+        continue;
+      if (avoidSetterIfUnchanged.includes(key) && object[key] === value)
+        continue;
+      state.descriptors[key].set?.call(object, value);
+    } catch {}
+  }
+  // Reset descriptors
+  Object.defineProperties(object, state.descriptors);
+
+  if (reorderProperties) {
+    // Delete and re-define each property so that they are in original order
+    const originalOrder = Object.keys(state.descriptors);
+    const properties = Object.getOwnPropertyDescriptors(object);
+    const sortedKeys = sortBy(Object.keys(properties), name =>
+      originalOrder.includes(name) ? originalOrder.indexOf(name) : 999,
+    );
+    for (const key of sortedKeys) {
+      delete object[key];
+      Object.defineProperty(object, key, properties[key]);
+    }
+  }
+}
+
+// #END https://github.com/TypeStrong/ts-node/blob/ddb05ef23be92a90c3ecac5a0220435c65ebbd2a/src/test/helpers/reset-node-environment.ts
+
 // The integration tests should not be mixed with other tests because the `register` function
 // will affect node's built-in ts support.
 describe("@babel/core config ts-node integration", () => {
@@ -19,6 +144,7 @@ describe("@babel/core config ts-node integration", () => {
   });
   afterAll(() => {
     service.enabled(false);
+    resetNodeEnvironment();
   });
   it("should work with ts-node", async () => {
     require(

yarn.lock

@@ -466,6 +466,7 @@ __metadata:
     "@babel/template": "workspace:^"
     "@babel/traverse": "workspace:^"
     "@babel/types": "workspace:^"
+    "@cspotcode/source-map-support": "npm:^0.8.1"
     "@jridgewell/trace-mapping": "npm:^0.3.28"
     "@types/convert-source-map": "npm:^2.0.0"
     "@types/gensync": "npm:^1.0.0"