test: add fixtures module

[matthewmeyer]

Replaced common.fixturesDir with usage of the common.fixtures module

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows [commit guidelines]

Affected core subsystem(s)

test

[tniessen]

CI: https://ci.nodejs.org/job/node-test-pull-request/10424/

[tniessen]

New linter CI: https://ci.nodejs.org/job/node-test-linter/12257/

[tniessen]

Landed in b1506f7, thank you for your contribution! 🎉

[eugeneo]

b1506f7 fails on my local Ubuntu setup:

node/test/parallel/test-require-resolve.js
module.js:507
    throw err;
    ^

Error: Cannot find module '(absolute path to my local code)/node/test/fixtures/a'

I verified locally that rolling it back fixes regression.

[tniessen]

@eugeneo Does this fix your problem?

index 27fb3f71f7..77f07b394f 100644
--- test/parallel/test-require-resolve.js
+++ test/parallel/test-require-resolve.js
@@ -26,7 +26,7 @@ const assert = require('assert');

 assert.strictEqual(
   fixtures.path('a.js').toLowerCase(),
-  require.resolve(fixtures.path('a').toLowerCase()));
+  require.resolve(fixtures.path('a')).toLowerCase());
 assert.strictEqual(
   fixtures.path('a.js').toLowerCase(),
   require.resolve(fixtures.path('a')).toLowerCase());

[bnoordhuis]

Seems there were not one but two regressions, see #16357 and #16486.