Convert markdownlint library to an ECMAScript module, replace markdownlint-micromark with micromark, stop publishing (large) markdownlint-browser.js, see https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c for guidance.

test/markdownlint-test-repos.mjs

@@ -0,0 +1,64 @@
+// @ts-check
+
+import path from "node:path";
+const { join } = path.posix;
+import { globby } from "globby";
+import jsoncParser from "jsonc-parser";
+import jsYaml from "js-yaml";
+import library from "../lib/markdownlint.mjs";
+const { markdownlint, readConfig } = library.promises;
+import { markdownlintParallel } from "./markdownlint-test-parallel.mjs";
+
+/**
+ * Lints a test repository.
+ *
+ * @param {Object} t Test instance.
+ * @param {string[]} globPatterns Array of files to in/exclude.
+ * @param {string} configPath Path to config file.
+ * @param {boolean} [parallel] True to lint in parallel.
+ * @returns {Promise} Test result.
+ */
+export function lintTestRepo(t, globPatterns, configPath, parallel) {
+  t.plan(1);
+  const jsoncParse = (json) => {
+    const config = jsoncParser.parse(json, [], { "allowTrailingComma": true });
+    return config.config || config;
+  };
+  const yamlParse = (yaml) => jsYaml.load(yaml);
+  return Promise.all([
+    globby(globPatterns),
+    readConfig(configPath, [ jsoncParse, yamlParse ])
+  ]).then((globbyAndReadConfigResults) => {
+    const [ files, rawConfig ] = globbyAndReadConfigResults;
+    // eslint-disable-next-line no-console
+    console.log(`${t.title}: Linting ${files.length} files...`);
+    const config = Object.fromEntries(
+      Object.entries(rawConfig)
+        .map(([ k, v ]) => [
+          k.replace(/header/, "heading"),
+          v
+        ])
+    );
+    return (parallel ? markdownlintParallel : markdownlint)({
+      files,
+      config
+    }).then((results) => {
+      const resultsString = results.toString();
+      t.snapshot(
+        resultsString,
+        "Expected linting violations"
+      );
+    });
+  });
+}
+
+/**
+ * Excludes a list of globs.
+ *
+ * @param {string} rootDir Root directory for globs.
+ * @param {...string} globs Globs to exclude.
+ * @returns {string[]} Array of excluded globs.
+ */
+export function excludeGlobs(rootDir, ...globs) {
+  return globs.map((glob) => "!" + join(rootDir, glob));
+}