[v14.x] build: pin build-docs workflow to Node.js 14

[richardlau]

The build-docs workflow runs tests which means it is sensitive to
globals and can fail if the node running the test has a different
set of globals to that expected by test/common.

e.g failure on current v14.x-staging
https://github.com/nodejs/node/runs/4301335343?check_suite_focus=true

=== release test-apilinks ===
Path: doctool/test-apilinks
Error: --- stderr ---
node:assert:171
  throw err;
  ^

AssertionError [ERR_ASSERTION]: Unexpected global(s) found: performance
    at process.<anonymous> (/home/runner/work/node/node/test/common/index.js:302:14)
    at process.emit (node:events:402:35) {
  generatedMessage: false,
  code: 'ERR_ASSERTION',
  actual: undefined,
  expected: undefined,
  operator: 'fail'
}
Command: /opt/hostedtoolcache/node/16.13.0/x64/bin/node /home/runner/work/node/node/test/doctool/test-apilinks.mjs

compare to

node/test/common/index.js

Lines 253 to 262 in 0682370

	let knownGlobals = [
	clearImmediate,
	clearInterval,
	clearTimeout,
	global,
	setImmediate,
	setInterval,
	setTimeout,
	queueMicrotask,
	];

[aduh95]

Another solution would be to backport those checks:

node/test/common/index.js

Lines 279 to 301 in d0fa1e9

	if (global.AbortController)
	knownGlobals.push(global.AbortController);
	if (global.gc) {
	knownGlobals.push(global.gc);
	}
	if (global.performance) {
	knownGlobals.push(global.performance);
	}
	if (global.PerformanceMark) {
	knownGlobals.push(global.PerformanceMark);
	}
	if (global.PerformanceMeasure) {
	knownGlobals.push(global.PerformanceMeasure);
	}
	// TODO(@ethan-arrowood): Similar to previous checks, this can be temporary
	// until v16.x is EOL. Once all supported versions have structuredClone we
	// can add this to the list above instead.
	if (global.structuredClone) {
	knownGlobals.push(global.structuredClone);
	}

[richardlau]

Another solution would be to backport those checks:

node/test/common/index.js

Lines 279 to 301 in d0fa1e9

	if (global.AbortController)
	knownGlobals.push(global.AbortController);
	if (global.gc) {
	knownGlobals.push(global.gc);
	}
	if (global.performance) {
	knownGlobals.push(global.performance);
	}
	if (global.PerformanceMark) {
	knownGlobals.push(global.PerformanceMark);
	}
	if (global.PerformanceMeasure) {
	knownGlobals.push(global.PerformanceMeasure);
	}
	// TODO(@ethan-arrowood): Similar to previous checks, this can be temporary
	// until v16.x is EOL. Once all supported versions have structuredClone we
	// can add this to the list above instead.
	if (global.structuredClone) {
	knownGlobals.push(global.structuredClone);
	}

I don't think we'd want to allow accidentally introducing new globals into LTS though.

[github-actions]

Fast-track has been requested by @richardlau. Please 👍 to approve.

[richardlau]

Landed in fb0af94

[Trott]

Probably would be good to include a comment so people don't update it to lts/* subsequently.

[Trott]

Oh, wait, this is on the 14.x-staging branch. Yeah, that (probably) doesn't need a comment.

[richardlau]

I'm undecided about whether to land something similar on later release lines or master. At least 14 is in maintenance which means we have no plans to introduce new globals.