ensure tests are forced to install and use most recent ts-node tarball and cannot accidentally use project-root nor outdated tarball

Author: cspotcode

ava.config.cjs

@@ -0,0 +1,39 @@
+const expect = require('expect');
+const { createRequire } = require('module');
+
+module.exports = {
+  files: ['dist/test/**/*.spec.js'],
+  failWithoutAssertions: false,
+  environmentVariables: {
+    ts_node_install_lock: `id-${Math.floor(Math.random() * 10e9)}`,
+    // Force jest expect() errors to generate colorized strings, makes output more readable.
+    // Delete the env var within ava processes via `require` option below.
+    // This avoids passing it to spawned processes under test, which would negatively affect
+    // their behavior.
+    FORCE_COLOR: '3',
+  },
+  require: ['./src/test/remove-env-var-force-color.js'],
+  timeout: '300s',
+  concurrency: 1,
+};
+
+{
+  /*
+   * Tests *must* install and use our most recent ts-node tarball.
+   * We must prevent them from accidentally require-ing a different version of
+   * ts-node, from either node_modules or tests/node_modules
+   */
+
+  const { rmSync, existsSync } = require('fs-extra');
+  const { resolve } = require('path');
+
+  remove(resolve(__dirname, 'node_modules/ts-node'));
+  remove(resolve(__dirname, 'tests/node_modules/ts-node'));
+
+  // Prove that we did it correctly
+  expect(() => {createRequire(resolve(__dirname, 'tests/foo.js')).resolve('ts-node')}).toThrow();
+
+  function remove(p) {
+    if(existsSync(p)) rmSync(p, {recursive: true})
+  }
+}

ava.config.js

@@ -127,6 +127,7 @@
     "axios": "^0.21.1",
     "chai": "^4.0.1",
     "expect": "^27.0.2",
+    "fs-extra": "^10.0.1",
     "get-stream": "^6.0.0",
     "lodash": "^4.17.15",
     "ntypescript": "^1.201507091536.1",