From 12f1c31a0decb867f91f31ffb0cadf34ce9f0673 Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Mon, 12 Feb 2024 23:33:51 +0100
Subject: [PATCH] chore(tests): use separate envs for each tests (#371)

---
 tests/Disable.test.ts          |  27 ++--
 tests/Enable.test.ts           |  35 ++---
 tests/Up.test.ts               |   1 +
 tests/Use.test.ts              |   1 +
 tests/main.test.ts             | 240 ++++++++++++++-------------------
 tests/npmRegistryUtils.test.ts |  15 +--
 tests/setupTests.js            |  56 ++++----
 7 files changed, 166 insertions(+), 209 deletions(-)

diff --git a/tests/Disable.test.ts b/tests/Disable.test.ts
index 9c93f9d7b..682a6817c 100644
--- a/tests/Disable.test.ts
+++ b/tests/Disable.test.ts
@@ -12,6 +12,7 @@ import {runCli}                               from './_runCli';
 const engine = new Engine();
 
 beforeEach(async () => {
+  // `process.env` is reset after each tests in setupTests.js.
   process.env.COREPACK_HOME = npath.fromPortablePath(await xfs.mktempPromise());
 });
 
@@ -26,15 +27,10 @@ describe(`DisableCommand`, () => {
           for (const variant of getBinaryNames(binName))
             await makeBin(cwd, variant as Filename, {ignorePlatform: true});
 
-      const PATH = process.env.PATH;
-      try {
-        process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${PATH}`;
-        await expect(runCli(cwd, [`disable`])).resolves.toMatchObject({
-          exitCode: 0,
-        });
-      } finally {
-        process.env.PATH = PATH;
-      }
+      process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${process.env.PATH}`;
+      await expect(runCli(cwd, [`disable`])).resolves.toMatchObject({
+        exitCode: 0,
+      });
 
       const sortedEntries = xfs.readdirPromise(cwd).then(entries => {
         return entries.sort();
@@ -84,15 +80,10 @@ describe(`DisableCommand`, () => {
       const dontRemoveBin = await makeBin(cwd, `dont-remove` as Filename);
       binNames.add(ppath.basename(dontRemoveBin));
 
-      const PATH = process.env.PATH;
-      try {
-        process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${PATH}`;
-        await expect(runCli(cwd, [`disable`, `yarn`])).resolves.toMatchObject({
-          exitCode: 0,
-        });
-      } finally {
-        process.env.PATH = PATH;
-      }
+      process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${process.env.PATH}`;
+      await expect(runCli(cwd, [`disable`, `yarn`])).resolves.toMatchObject({
+        exitCode: 0,
+      });
 
       for (const variant of getBinaryNames(`yarn`))
         binNames.delete(variant);
diff --git a/tests/Enable.test.ts b/tests/Enable.test.ts
index ce9a8a9e3..b0f4e168f 100644
--- a/tests/Enable.test.ts
+++ b/tests/Enable.test.ts
@@ -12,6 +12,7 @@ import {runCli}                                                         from './
 const engine = new Engine();
 
 beforeEach(async () => {
+  // `process.env` is reset after each tests in setupTests.js.
   process.env.COREPACK_HOME = npath.fromPortablePath(await xfs.mktempPromise());
   process.env.COREPACK_DEFAULT_TO_LATEST = `0`;
 });
@@ -21,17 +22,12 @@ describe(`EnableCommand`, () => {
     await xfs.mktempPromise(async cwd => {
       const corepackBin = await makeBin(cwd, `corepack` as Filename);
 
-      const PATH = process.env.PATH;
-      try {
-        process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${PATH}`;
-        await expect(runCli(cwd, [`enable`])).resolves.toMatchObject({
-          stdout: ``,
-          stderr: ``,
-          exitCode: 0,
-        });
-      } finally {
-        process.env.PATH = PATH;
-      }
+      process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${process.env.PATH}`;
+      await expect(runCli(cwd, [`enable`])).resolves.toMatchObject({
+        stdout: ``,
+        stderr: ``,
+        exitCode: 0,
+      });
 
       const sortedEntries = xfs.readdirPromise(cwd).then(entries => {
         return entries.sort();
@@ -73,17 +69,12 @@ describe(`EnableCommand`, () => {
     await xfs.mktempPromise(async cwd => {
       const corepackBin = await makeBin(cwd, `corepack` as Filename);
 
-      const PATH = process.env.PATH;
-      try {
-        process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${PATH}`;
-        await expect(runCli(cwd, [`enable`, `yarn`])).resolves.toMatchObject({
-          stdout: ``,
-          stderr: ``,
-          exitCode: 0,
-        });
-      } finally {
-        process.env.PATH = PATH;
-      }
+      process.env.PATH = `${npath.fromPortablePath(cwd)}${delimiter}${process.env.PATH}`;
+      await expect(runCli(cwd, [`enable`, `yarn`])).resolves.toMatchObject({
+        stdout: ``,
+        stderr: ``,
+        exitCode: 0,
+      });
 
       const sortedEntries = xfs.readdirPromise(cwd).then(entries => {
         return entries.sort();
diff --git a/tests/Up.test.ts b/tests/Up.test.ts
index 1c78afdc5..c1c094f43 100644
--- a/tests/Up.test.ts
+++ b/tests/Up.test.ts
@@ -5,6 +5,7 @@ import process                            from 'node:process';
 import {runCli}                           from './_runCli';
 
 beforeEach(async () => {
+  // `process.env` is reset after each tests in setupTests.js.
   process.env.COREPACK_HOME = npath.fromPortablePath(await xfs.mktempPromise());
   process.env.COREPACK_DEFAULT_TO_LATEST = `0`;
 });
diff --git a/tests/Use.test.ts b/tests/Use.test.ts
index 10deef19e..8c91fa217 100644
--- a/tests/Use.test.ts
+++ b/tests/Use.test.ts
@@ -5,6 +5,7 @@ import process                            from 'node:process';
 import {runCli}                           from './_runCli';
 
 beforeEach(async () => {
+  // `process.env` is reset after each tests in setupTests.js.
   process.env.COREPACK_HOME = npath.fromPortablePath(await xfs.mktempPromise());
   process.env.COREPACK_DEFAULT_TO_LATEST = `0`;
 });
diff --git a/tests/main.test.ts b/tests/main.test.ts
index c54fb1f5d..ec05db235 100644
--- a/tests/main.test.ts
+++ b/tests/main.test.ts
@@ -9,6 +9,7 @@ import {runCli}                                    from './_runCli';
 
 
 beforeEach(async () => {
+  // `process.env` is reset after each tests in setupTests.js.
   process.env.COREPACK_HOME = npath.fromPortablePath(await xfs.mktempPromise());
   process.env.COREPACK_DEFAULT_TO_LATEST = `0`;
 });
@@ -344,15 +345,11 @@ it(`should allow to call "corepack install" without arguments within a configure
     // Disable the network to make sure we don't succeed by accident
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-    try {
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `1.0.0\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_NETWORK;
-    }
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `1.0.0\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
@@ -372,21 +369,16 @@ it(`should refuse to run a different package manager within a configured project
     // Disable strict checking to workaround the UsageError.
     process.env.COREPACK_ENABLE_STRICT = `0`;
 
-    try {
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `1.0.0\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-      await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_STRICT;
-      delete process.env.FORCE_COLOR;
-    }
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `1.0.0\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
+    await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
@@ -398,20 +390,16 @@ it(`should always use fallback version when project spec env is disabled`, async
     });
     process.env.COREPACK_ENABLE_PROJECT_SPEC = `0`;
 
-    try {
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.yarn.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-      await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_PROJECT_SPEC;
-    }
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.yarn.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
+    await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
@@ -428,48 +416,40 @@ it(`should allow to call "corepack install -g --all" to prepare all package mana
 
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-    try {
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.yarn.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.yarn.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.pnpm.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await expect(runCli(cwd, [`npm`, `--version`])).resolves.toMatchObject({
-        stdout: `${config.definitions.npm.default.split(`+`, 1)[0]}\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_NETWORK;
-    }
+    await expect(runCli(cwd, [`npm`, `--version`])).resolves.toMatchObject({
+      stdout: `${config.definitions.npm.default.split(`+`, 1)[0]}\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
 it(`should support disabling the network accesses from the environment`, async () => {
   process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-  try {
-    await xfs.mktempPromise(async cwd => {
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `yarn@2.2.2`,
-      });
+  await xfs.mktempPromise(async cwd => {
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `yarn@2.2.2`,
+    });
 
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: expect.stringContaining(`Network access disabled by the environment`),
-        stderr: ``,
-        exitCode: 1,
-      });
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: expect.stringContaining(`Network access disabled by the environment`),
+      stderr: ``,
+      exitCode: 1,
     });
-  } finally {
-    delete process.env.COREPACK_ENABLE_NETWORK;
-  }
+  });
 });
 
 it(`should support hydrating package managers from cached archives`, async () => {
@@ -485,24 +465,20 @@ it(`should support hydrating package managers from cached archives`, async () =>
     // Disable the network to make sure we don't succeed by accident
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-    try {
-      await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `yarn@2.2.2`,
-      });
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `yarn@2.2.2`,
+    });
 
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `2.2.2\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_NETWORK;
-    }
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `2.2.2\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
@@ -522,24 +498,20 @@ it(`should support hydrating package managers if cache folder was removed`, asyn
     // Disable the network to make sure we don't succeed by accident
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-    try {
-      await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `yarn@2.2.2`,
-      });
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `yarn@2.2.2`,
+    });
 
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `2.2.2\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_NETWORK;
-    }
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `2.2.2\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 });
 
@@ -556,34 +528,30 @@ it(`should support hydrating multiple package managers from cached archives`, as
     // Disable the network to make sure we don't succeed by accident
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
-    try {
-      await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`install`, `-g`, `corepack.tgz`])).resolves.toMatchObject({
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `yarn@2.2.2`,
-      });
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `yarn@2.2.2`,
+    });
 
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        stdout: `2.2.2\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: `2.2.2\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
 
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `pnpm@5.8.0`,
-      });
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `pnpm@5.8.0`,
+    });
 
-      await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
-        stdout: `5.8.0\n`,
-        stderr: ``,
-        exitCode: 0,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_NETWORK;
-    }
+    await expect(runCli(cwd, [`pnpm`, `--version`])).resolves.toMatchObject({
+      stdout: `5.8.0\n`,
+      stderr: ``,
+      exitCode: 0,
+    });
   });
 }, 180_000);
 
@@ -741,17 +709,13 @@ it(`should support package managers in ESM format`, async () => {
 it(`should show a warning on stderr before downloading when enable`, async() => {
   await xfs.mktempPromise(async cwd => {
     process.env.COREPACK_ENABLE_DOWNLOAD_PROMPT = `1`;
-    try {
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
-        packageManager: `yarn@3.0.0`,
-      });
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        exitCode: 0,
-        stdout: `3.0.0\n`,
-        stderr: `Corepack is about to download https://repo.yarnpkg.com/3.0.0/packages/yarnpkg-cli/bin/yarn.js.\n`,
-      });
-    } finally {
-      delete process.env.COREPACK_ENABLE_DOWNLOAD_PROMPT;
-    }
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      packageManager: `yarn@3.0.0`,
+    });
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      exitCode: 0,
+      stdout: `3.0.0\n`,
+      stderr: `Corepack is about to download https://repo.yarnpkg.com/3.0.0/packages/yarnpkg-cli/bin/yarn.js.\n`,
+    });
   });
 });
diff --git a/tests/npmRegistryUtils.test.ts b/tests/npmRegistryUtils.test.ts
index 1ee82a635..69dc0b582 100644
--- a/tests/npmRegistryUtils.test.ts
+++ b/tests/npmRegistryUtils.test.ts
@@ -1,4 +1,4 @@
-import {jest, describe, beforeEach, afterEach, it, expect}      from '@jest/globals';
+import {jest, describe, beforeEach, it, expect}                 from '@jest/globals';
 import {Buffer}                                                 from 'node:buffer';
 import process                                                  from 'node:process';
 
@@ -8,18 +8,12 @@ import {DEFAULT_HEADERS, DEFAULT_NPM_REGISTRY_URL, fetchAsJson} from '../sources
 jest.mock(`../sources/httpUtils`);
 
 describe(`npm registry utils fetchAsJson`, () => {
-  const OLD_ENV = process.env;
-
   beforeEach(() => {
-    process.env = {...OLD_ENV}; // Make a copy
     jest.resetAllMocks();
   });
 
-  afterEach(() => {
-    process.env = OLD_ENV; // Restore old environment
-  });
-
   it(`throw usage error if COREPACK_ENABLE_NETWORK env is set to 0`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_ENABLE_NETWORK = `0`;
 
     await expect(fetchAsJson(`package-name`)).rejects.toThrowError();
@@ -33,6 +27,7 @@ describe(`npm registry utils fetchAsJson`, () => {
   });
 
   it(`loads from custom COREPACK_NPM_REGISTRY if set`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_NPM_REGISTRY = `https://registry.example.org`;
     await fetchAsJson(`package-name`);
 
@@ -41,6 +36,7 @@ describe(`npm registry utils fetchAsJson`, () => {
   });
 
   it(`adds authorization header with bearer token if COREPACK_NPM_TOKEN is set`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_NPM_TOKEN = `foo`;
 
     await fetchAsJson(`package-name`);
@@ -53,6 +49,7 @@ describe(`npm registry utils fetchAsJson`, () => {
   });
 
   it(`only adds authorization header with bearer token if COREPACK_NPM_TOKEN and COREPACK_NPM_USERNAME are set`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_NPM_TOKEN = `foo`;
     process.env.COREPACK_NPM_USERNAME = `bar`;
     process.env.COREPACK_NPM_PASSWORD = `foobar`;
@@ -68,6 +65,7 @@ describe(`npm registry utils fetchAsJson`, () => {
 
 
   it(`adds authorization header with basic auth if COREPACK_NPM_USERNAME and COREPACK_NPM_PASSWORD are set`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_NPM_USERNAME = `foo`;
     process.env.COREPACK_NPM_PASSWORD = `bar`;
 
@@ -83,6 +81,7 @@ describe(`npm registry utils fetchAsJson`, () => {
   });
 
   it(`does not add authorization header if COREPACK_NPM_USERNAME is set and COREPACK_NPM_PASSWORD is not.`, async () => {
+    // `process.env` is reset after each tests in setupTests.js.
     process.env.COREPACK_NPM_USERNAME = `foo`;
 
     await fetchAsJson(`package-name`);
diff --git a/tests/setupTests.js b/tests/setupTests.js
index fdf59307c..cf8ca57f9 100644
--- a/tests/setupTests.js
+++ b/tests/setupTests.js
@@ -1,43 +1,53 @@
 /* global jest, expect, beforeEach, afterAll */
 
 const crypto = require(`crypto`);
+const process = require(`process`);
 
 jest.retryTimes(2, {logErrorsBeforeRetry: true});
 
+const OLD_ENV = process.env;
+const {
+  // To ensure we test the default behavior, we must remove these env vars
+  // in case the local machine already set these values.
+  COREPACK_DEFAULT_TO_LATEST,
+  COREPACK_ENABLE_NETWORK,
+  COREPACK_ENABLE_PROJECT_SPEC,
+  COREPACK_ENABLE_STRICT,
+  COREPACK_HOME,
+  COREPACK_NPM_REGISTRY,
+  COREPACK_NPM_TOKEN,
+  COREPACK_NPM_USERNAME,
+  FORCE_COLOR,
+  // We save the rest to put it into `process.env` for tests.
+  ...processEnv
+} = process.env;
+
 switch (process.env.NOCK_ENV || ``) {
   case `record`:
   case `replay`:
     beforeEach(() => {
-      // To ensure we test the default behavior, we must remove these env vars
-      // in case the local machine already set these values.
-      delete process.env.COREPACK_DEFAULT_TO_LATEST;
-      delete process.env.COREPACK_ENABLE_NETWORK;
-      delete process.env.COREPACK_ENABLE_PROJECT_SPEC;
-      delete process.env.COREPACK_ENABLE_STRICT;
-      delete process.env.COREPACK_HOME;
-      delete process.env.COREPACK_NPM_REGISTRY;
-      delete process.env.COREPACK_NPM_TOKEN;
-      delete process.env.COREPACK_NPM_USERNAME;
-      delete process.env.FORCE_COLOR;
-
-      process.env.RUN_CLI_ID = 0;
-      process.env.NOCK_FILE_NAME = crypto
-        .createHash(`md5`)
-        .update(expect.getState().currentTestName)
-        .digest(`base64url`);
-    });
-
-    afterAll(() => {
-      delete process.env.RUN_CLI_ID;
-      delete process.env.NOCK_FILE_NAME;
+      process.env = {
+        ...processEnv,
+        RUN_CLI_ID: `0`,
+        NOCK_FILE_NAME: crypto
+          .createHash(`md5`)
+          .update(expect.getState().currentTestName)
+          .digest(`base64url`),
+      };
     });
     break;
 
   case ``: {
-    // Nothing
+    beforeEach(() => {
+      process.env = {...processEnv};
+    });
   } break;
 
   default: {
     throw new Error(`Invalid NOCK_ENV variable`);
   }
 }
+
+afterAll(() => {
+  process.env = OLD_ENV;
+});