fix(instrumenter): Use globalThis when available (#4169)

Use `globalThis` to reference the global object when available for mutant schemata workings. Only falling back to `(new Function("return this"))` when it is `globalThis` is not available.

Fixes `EvalError: Code generation from strings disallowed for this context` errors when using the  [--disallow-code-generation-from-strings cli option.](https://nodejs.org/api/cli.html#--disallow-code-generation-from-strings).

e2e/test/disallow-code-generation-from-strings/.mocharc.jsonc

@@ -0,0 +1,3 @@
+{
+    "spec": ["src/**/*.spec.js"]
+}

e2e/test/disallow-code-generation-from-strings/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "disallow-code-generation-from-strings",
+  "version": "1.0.0",
+  "description": "A e2e test for running node with --disallow-code-generation-from-strings. See https://github.com/stryker-mutator/stryker-js/issues/4035",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "test:unit": "cross-env NODE_OPTIONS='--disallow-code-generation-from-strings' mocha",
+    "test": "stryker run",
+    "posttest": "mocha --no-config --no-timeout verify/verify.js"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}

e2e/test/disallow-code-generation-from-strings/src/math.js

@@ -0,0 +1,3 @@
+export function add(a, b) {
+  return a + b;
+}

e2e/test/disallow-code-generation-from-strings/src/math.spec.js

@@ -0,0 +1,8 @@
+import { expect } from 'chai';
+import { add } from './math.js';
+
+describe(add.name, () => {
+  it('should add 40, 2 to be 42', () => {
+    expect(add(40, 2)).eq(42);
+  })
+});

e2e/test/disallow-code-generation-from-strings/stryker.conf.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "../../node_modules/@stryker-mutator/core/schema/stryker-schema.json",
+  "concurrency": 1,
+  "reporters": ["json", "clear-text"],
+  "testRunner": "command",
+  "commandRunner": { "command": "npm run test:unit" },
+  "plugins": ["@stryker-mutator/mocha-runner"]
+}

e2e/test/disallow-code-generation-from-strings/verify/verify.js

@@ -0,0 +1,7 @@
+import { expectMetricsJsonToMatchSnapshot } from '../../../helpers.js';
+
+describe('After running stryker --disallow-code-generation-from-strings', () => {
+  it('should report the mutation score correctly', async () => {
+    await expectMetricsJsonToMatchSnapshot();
+  });
+});

e2e/test/disallow-code-generation-from-strings/verify/verify.js.snap

@@ -0,0 +1,22 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`After running stryker --disallow-code-generation-from-strings should report the mutation score correctly 1`] = `
+Object {
+  "compileErrors": 0,
+  "ignored": 0,
+  "killed": 2,
+  "mutationScore": 100,
+  "mutationScoreBasedOnCoveredCode": 100,
+  "noCoverage": 0,
+  "pending": 0,
+  "runtimeErrors": 0,
+  "survived": 0,
+  "timeout": 0,
+  "totalCovered": 2,
+  "totalDetected": 2,
+  "totalInvalid": 0,
+  "totalMutants": 2,
+  "totalUndetected": 0,
+  "totalValid": 2,
+}
+`;

packages/instrumenter/src/util/syntax-helpers.ts

@@ -16,9 +16,10 @@ const { types, traverse, parse } = babel;
  * Returns syntax for the header if JS/TS files
  */
 export const instrumentationBabelHeader = deepFreeze(
+  // `globalThis` implementation is based on core-js's implementation. See https://github.com/stryker-mutator/stryker-js/issues/4035
   parse(
     `function ${STRYKER_NAMESPACE_HELPER}(){
-  var g = new Function("return this")();
+  var g = typeof globalThis === 'object' && globalThis && globalThis.Math === Math && globalThis || new Function("return this")();
   var ns = g.${ID.NAMESPACE} || (g.${ID.NAMESPACE} = {});
   if (ns.${ID.ACTIVE_MUTANT} === undefined && g.process && g.process.env && g.process.env.${ID.ACTIVE_MUTANT_ENV_VARIABLE}) {
     ns.${ID.ACTIVE_MUTANT} = g.process.env.${ID.ACTIVE_MUTANT_ENV_VARIABLE};