Convert spec URLs test to linter unit (mdn#16522)

Co-authored-by: Philip Jägenstedt <philip@foolip.org>

test/linter/index.js

@@ -11,6 +11,7 @@ import testLinks from './test-links.js';
 import testNotes from './test-notes.js';
 import testPrefix from './test-prefix.js';
 import testSchema from './test-schema.js';
+import testSpecURLs from './test-spec-urls.js';
 import testStatus from './test-status.js';
 import testStyle from './test-style.js';
 import testVersions from './test-versions.js';
@@ -24,6 +25,7 @@ export default new Linters([
   testNotes,
   testPrefix,
   testSchema,
+  testSpecURLs,
   testStatus,
   testStyle,
   testVersions,

test/linter/test-spec-urls.js

@@ -0,0 +1,91 @@
+/* This file is a part of @mdn/browser-compat-data
+ * See LICENSE file for more information. */
+
+import chalk from 'chalk-template';
+
+import specData from 'browser-specs' assert { type: 'json' };
+
+/*
+ * Before adding an exception, open an issue with https://github.com/w3c/browser-specs to
+ * see if a spec should be added there instead.
+ * When adding an exception here, provide a reason and indicate how the exception can be removed.
+ */
+const specsExceptions = [
+  // Remove once https://github.com/whatwg/html/pull/6715 is resolved
+  'https://wicg.github.io/controls-list/',
+
+  // Remove once Window.{clearImmediate,setImmediate} are irrelevant and removed
+  'https://w3c.github.io/setImmediate/',
+
+  // Remove if supported in browser-specs https://github.com/w3c/browser-specs/issues/339
+  'https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-digest-headers-05',
+  'https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-expect-ct-08',
+
+  // Exception for April Fools' joke for "418 I'm a teapot"
+  'https://www.rfc-editor.org/rfc/rfc2324',
+
+  // Unfortunately this doesn't produce a rendered spec, so it isn't in browser-specs
+  // Remove if it is in the main ECMA spec
+  'https://github.com/tc39/proposal-regexp-legacy-features/',
+
+  // For the 'shared' flag in WebAssembly.Memory
+  // Remove if this spec will be merged with the main WebAssembly spec
+  'https://webassembly.github.io/threads/js-api/',
+
+  // Not really a browser feature, thus not in browser-specs
+  // Remove if it is in the main ECMA spec
+  'https://tc39.es/proposal-hashbang/out.html',
+
+  // Remove if https://github.com/w3c/webrtc-extensions/issues/108 is closed
+  'https://w3c.github.io/webrtc-extensions/',
+
+  // Remove if https://github.com/w3c/mathml/issues/216 is resolved
+  'https://w3c.github.io/mathml/',
+];
+
+const allowedSpecURLs = [
+  ...specData.map((spec) => spec.url),
+  ...specData.map((spec) => spec.nightly.url),
+  ...specData.map((spec) => spec.series.nightlyUrl),
+  ...specsExceptions,
+];
+
+/**
+ * @typedef {import('../../types').Identifier} Identifier
+ * @typedef {import('../utils').Logger} Logger
+ */
+
+/**
+ * Process the data for spec URL errors
+ *
+ * @param {Identifier} data The data to test
+ * @param {Logger} logger The logger to output errors to
+ * @returns {void}
+ */
+function processData(data, logger) {
+  if (!data.spec_url) {
+    return;
+  }
+
+  const featureSpecURLs = Array.isArray(data.spec_url)
+    ? data.spec_url
+    : [data.spec_url];
+
+  for (const specURL of featureSpecURLs) {
+    if (!allowedSpecURLs.some((prefix) => specURL.startsWith(prefix))) {
+      logger.error(
+        chalk`Invalid specification URL found: {bold ${specURL}}. Try a more current specification URL and/or check if the specification URL is listed in https://github.com/w3c/browser-specs.`,
+      );
+    }
+  }
+}
+
+export default {
+  name: 'Spec URLs',
+  description:
+    'Ensure the spec_url values match spec URLs in w3c/browser-specs (or defined exceptions)',
+  scope: 'feature',
+  check(logger, { data }) {
+    processData(data, logger);
+  },
+};