Stop using module.createRequire (problematic under webpack), incorporate and export resolveModule helper from markdownlint-cli2.

Author: DavidAnson

Diff for: .gitignore

@@ -4,6 +4,7 @@ demo/markdownlint-browser.js
 demo/markdownlint-browser.min.js
 node_modules
 !test/node_modules
+!test/rules/node_modules
 npm-debug.log
 test-repos
 .DS_Store

Diff for: lib/defer-require.cjs

@@ -0,0 +1,16 @@
+// @ts-check
+
+"use strict";
+
+/**
+ * Calls require for markdownit.cjs. Used to synchronously defer loading because module.createRequire is buggy under webpack (https://github.com/webpack/webpack/issues/16724).
+ *
+ * @returns {any} Exported module content.
+ */
+function requireMarkdownItCjs() {
+  return require("./markdownit.cjs");
+}
+
+module.exports = {
+  requireMarkdownItCjs
+};

Diff for: lib/exports.d.mts

@@ -1,3 +1,4 @@
+export { resolveModule } from "./resolve-module.cjs";
 export type Configuration = import("./markdownlint.mjs").Configuration;
 export type ConfigurationParser = import("./markdownlint.mjs").ConfigurationParser;
 export type ConfigurationStrict = import("./markdownlint.mjs").ConfigurationStrict;

Diff for: lib/exports.mjs

@@ -1,6 +1,7 @@
 // @ts-check
 
 export { applyFix, applyFixes, getVersion } from "./markdownlint.mjs";
+export { resolveModule } from "./resolve-module.cjs";
 
 /** @typedef {import("./markdownlint.mjs").Configuration} Configuration */
 /** @typedef {import("./markdownlint.mjs").ConfigurationParser} ConfigurationParser */

Diff for: lib/markdownlint.mjs

@@ -1,10 +1,11 @@
 // @ts-check
 
 // @ts-ignore
-import { fs as nodeFs, module, os, path } from "#node-imports";
-const dynamicRequire = module.createRequire(import.meta.url);
+import { fs as nodeFs, os, path } from "#node-imports";
 import { initialize as cacheInitialize } from "./cache.mjs";
 import { version } from "./constants.mjs";
+import { requireMarkdownItCjs } from "./defer-require.cjs";
+import { resolveModule } from "./resolve-module.cjs";
 import rules from "./rules.mjs";
 import { parse as micromarkParse } from "./micromark-parse.mjs";
 import * as helpers from "../helpers/helpers.cjs";
@@ -501,7 +502,7 @@ function lintContent(
   // Parse content into lines and get markdown-it tokens
   const lines = content.split(helpers.newLineRe);
   const markdownitTokens = needMarkdownItTokens ?
-    dynamicRequire("./markdownit.cjs").getMarkdownItTokens(markdownItPlugins, preClearedContent, lines) :
+    requireMarkdownItCjs().getMarkdownItTokens(markdownItPlugins, preClearedContent, lines) :
     [];
   // Create (frozen) parameters for rules
   /** @type {MarkdownParsers} */
@@ -1010,10 +1011,10 @@ function resolveConfigExtends(configFile, referenceId, fs, callback) {
     if (err) {
       // Not a file, try require.resolve
       try {
-        return callback(null, dynamicRequire.resolve(
-          referenceId,
-          { "paths": [ configFileDirname ] }
-        ));
+        return callback(
+          null,
+          resolveModule(referenceId, [ configFileDirname ])
+        );
       } catch {
         // Unable to resolve, use resolvedExtendsFile
       }
@@ -1041,10 +1042,7 @@ function resolveConfigExtendsSync(configFile, referenceId, fs) {
     // Not a file, try require.resolve
   }
   try {
-    return dynamicRequire.resolve(
-      referenceId,
-      { "paths": [ configFileDirname ] }
-    );
+    return resolveModule(referenceId, [ configFileDirname ]);
   } catch {
     // Unable to resolve, return resolvedExtendsFile
   }

Diff for: lib/node-imports-browser-module.cjs

@@ -12,8 +12,6 @@ export const fs = {
   "readFileSync": throwForSync
 };
 
-export { default as module } from "./node-imports-browser-module.cjs";
-
 export const os = {};
 
 export const path = {

Diff for: lib/node-imports-browser.mjs

@@ -3,9 +3,6 @@
 import { access, accessSync, readFile, readFileSync } from "node:fs";
 export const fs = { access, accessSync, readFile, readFileSync };
 
-import { createRequire } from "node:module";
-export const module = { createRequire };
-
 import { EOL, homedir } from "node:os";
 export const os = { EOL, homedir };
 

Diff for: lib/node-imports-node.mjs

@@ -0,0 +1,52 @@
+// @ts-check
+
+"use strict";
+
+// @ts-ignore
+// eslint-disable-next-line camelcase, no-inline-comments, no-undef
+const nativeRequire = (typeof __non_webpack_require__ === "undefined") ? require : /* c8 ignore next */ __non_webpack_require__;
+// Captures the native require implementation (even under webpack).
+
+/**
+ * @typedef RequireResolveOptions
+ * @property {string[]} [paths] Additional paths to resolve from.
+ */
+
+/**
+ * @callback RequireResolve
+ * @param {string} id Module name or path.
+ * @param {RequireResolveOptions} options Options to apply.
+ * @returns {string} Resolved module path.
+ */
+
+/**
+ * Resolves modules according to Node's resolution rules.
+ *
+ * @param {RequireResolve} resolve Node-like require.resolve implementation.
+ * @param {string} id Module name or path.
+ * @param {string[]} [paths] Additional paths to resolve from.
+ * @returns {string} Resolved module path.
+ */
+const resolveModuleCustomResolve = (resolve, id, paths = []) => {
+  // resolve.paths is sometimes not present under webpack or VS Code
+  // @ts-ignore
+  const resolvePaths = resolve.paths?.("") || [];
+  const allPaths = [ ...paths, ...resolvePaths ];
+  return resolve(id, { "paths": allPaths });
+};
+
+/**
+ * Resolves modules according to Node's resolution rules.
+ *
+ * @param {string} id Module name or path.
+ * @param {string[]} [paths] Additional paths to resolve from.
+ * @returns {string} Resolved module path.
+ */
+const resolveModule = (id, paths) => (
+  resolveModuleCustomResolve(nativeRequire.resolve, id, paths)
+);
+
+module.exports = {
+  resolveModule,
+  resolveModuleCustomResolve
+};

Diff for: lib/resolve-module.cjs

@@ -0,0 +1,34 @@
+export type RequireResolveOptions = {
+    /**
+     * Additional paths to resolve from.
+     */
+    paths?: string[];
+};
+export type RequireResolve = (id: string, options: RequireResolveOptions) => string;
+/**
+ * Resolves modules according to Node's resolution rules.
+ *
+ * @param {string} id Module name or path.
+ * @param {string[]} [paths] Additional paths to resolve from.
+ * @returns {string} Resolved module path.
+ */
+export function resolveModule(id: string, paths?: string[]): string;
+/**
+ * @typedef RequireResolveOptions
+ * @property {string[]} [paths] Additional paths to resolve from.
+ */
+/**
+ * @callback RequireResolve
+ * @param {string} id Module name or path.
+ * @param {RequireResolveOptions} options Options to apply.
+ * @returns {string} Resolved module path.
+ */
+/**
+ * Resolves modules according to Node's resolution rules.
+ *
+ * @param {RequireResolve} resolve Node-like require.resolve implementation.
+ * @param {string} id Module name or path.
+ * @param {string[]} [paths] Additional paths to resolve from.
+ * @returns {string} Resolved module path.
+ */
+export function resolveModuleCustomResolve(resolve: RequireResolve, id: string, paths?: string[]): string;

Diff for: lib/resolve-module.d.cts

@@ -36,7 +36,7 @@
     "build-config": "npm run build-config-schema && npm run build-config-example",
     "build-config-example": "node schema/build-config-example.mjs",
     "build-config-schema": "node schema/build-config-schema.mjs",
-    "build-declaration": "tsc --allowJs --checkJs --declaration --emitDeclarationOnly --module nodenext --outDir dts --rootDir . --target es2015 lib/exports.mjs lib/exports-async.mjs lib/exports-promise.mjs lib/exports-sync.mjs lib/markdownlint.mjs && node scripts/index.mjs copy dts/lib/exports.d.mts lib/exports.d.mts && node scripts/index.mjs copy dts/lib/exports-async.d.mts lib/exports-async.d.mts && node scripts/index.mjs copy dts/lib/exports-promise.d.mts lib/exports-promise.d.mts && node scripts/index.mjs copy dts/lib/exports-sync.d.mts lib/exports-sync.d.mts && node scripts/index.mjs copy dts/lib/markdownlint.d.mts lib/markdownlint.d.mts && node scripts/index.mjs remove dts",
+    "build-declaration": "tsc --allowJs --checkJs --declaration --emitDeclarationOnly --module nodenext --outDir dts --rootDir . --target es2015 lib/exports.mjs lib/exports-async.mjs lib/exports-promise.mjs lib/exports-sync.mjs lib/markdownlint.mjs lib/resolve-module.cjs && node scripts/index.mjs copy dts/lib/exports.d.mts lib/exports.d.mts && node scripts/index.mjs copy dts/lib/exports-async.d.mts lib/exports-async.d.mts && node scripts/index.mjs copy dts/lib/exports-promise.d.mts lib/exports-promise.d.mts && node scripts/index.mjs copy dts/lib/exports-sync.d.mts lib/exports-sync.d.mts && node scripts/index.mjs copy dts/lib/markdownlint.d.mts lib/markdownlint.d.mts && node scripts/index.mjs copy dts/lib/resolve-module.d.cts lib/resolve-module.d.cts && node scripts/index.mjs remove dts",
     "build-demo": "node scripts/index.mjs copy node_modules/markdown-it/dist/markdown-it.min.js demo/markdown-it.min.js && cd demo && webpack --no-stats",
     "build-docs": "node doc-build/build-rules.mjs",
     "build-example": "npm install --no-save --ignore-scripts grunt grunt-cli gulp through2",
@@ -59,7 +59,7 @@
     "lint-test-repos": "ava --timeout=10m test/markdownlint-test-repos-*.mjs",
     "serial-config-docs": "npm run build-config && npm run build-docs",
     "serial-declaration-demo": "npm run build-declaration && npm-run-all --continue-on-error --parallel build-demo test-declaration",
-    "test": "ava --timeout=30s test/markdownlint-test.mjs test/markdownlint-test-config.mjs test/markdownlint-test-custom-rules.mjs test/markdownlint-test-fixes.mjs test/markdownlint-test-helpers.mjs test/markdownlint-test-micromark.mjs test/markdownlint-test-result-object.mjs test/markdownlint-test-scenarios.mjs helpers/test.cjs",
+    "test": "ava --timeout=30s test/markdownlint-test.mjs test/markdownlint-test-config.mjs test/markdownlint-test-custom-rules.mjs test/markdownlint-test-fixes.mjs test/markdownlint-test-helpers.mjs test/markdownlint-test-micromark.mjs test/markdownlint-test-result-object.mjs test/markdownlint-test-scenarios.mjs test/resolve-module-test.mjs helpers/test.cjs",
     "test-cover": "c8 --100 npm test",
     "test-declaration": "cd example/typescript && tsc --module commonjs && tsc --module nodenext && node type-check.js",
     "test-extra": "ava --timeout=10m test/markdownlint-test-extra-parse.mjs test/markdownlint-test-extra-type.mjs",

Diff for: package.json

@@ -0,0 +1,147 @@
+// @ts-check
+
+import test from "ava";
+import path from "node:path";
+import { __dirname as getDirname } from "./esm-helpers.mjs";
+import { resolveModule, resolveModuleCustomResolve } from "../lib/resolve-module.cjs";
+
+import { createRequire } from "node:module";
+const require = createRequire(import.meta.url);
+// eslint-disable-next-line no-underscore-dangle
+const __dirname = getDirname(import.meta);
+
+test("built-in module", (t) => {
+  t.plan(1);
+  t.deepEqual(
+    resolveModule("node:fs"),
+    require.resolve("node:fs")
+  );
+});
+
+test("locally-installed module", (t) => {
+  t.plan(1);
+  t.deepEqual(
+    resolveModule("micromark"),
+    require.resolve("micromark")
+  );
+});
+
+test("absolute path to module", (t) => {
+  t.plan(1);
+  const absolute =
+    path.resolve(
+      __dirname,
+      "./rules/node_modules/markdownlint-rule-sample-commonjs"
+    );
+  t.deepEqual(
+    resolveModule(absolute),
+    require.resolve(absolute)
+  );
+});
+
+test("relative (to __dirname) path to module", (t) => {
+  t.plan(1);
+  t.deepEqual(
+    resolveModule(
+      "./rules/node_modules/markdownlint-rule-sample-module",
+      // __dirname is needed because require.resolve is relative to this
+      // file while resolveModule is relative to resolve-module.cjs
+      [ __dirname ]
+    ),
+    require.resolve(
+      "./rules/node_modules/markdownlint-rule-sample-module"
+    )
+  );
+});
+
+test("module in alternate node_modules", (t) => {
+  t.plan(3);
+  t.throws(
+    () => require.resolve("markdownlint-rule-sample-commonjs"),
+    { "code": "MODULE_NOT_FOUND" }
+  );
+  t.throws(
+    () => resolveModule("markdownlint-rule-sample-commonjs"),
+    { "code": "MODULE_NOT_FOUND" }
+  );
+  t.deepEqual(
+    resolveModule(
+      "markdownlint-rule-sample-commonjs",
+      [ path.join(__dirname, "rules") ]
+    ),
+    require.resolve(
+      "markdownlint-rule-sample-commonjs",
+      { "paths": [ path.join(__dirname, "rules") ] }
+    )
+  );
+});
+
+test("module local, relative, and in alternate node_modules (same paths)", (t) => {
+  t.plan(3);
+  const paths = [
+    __dirname,
+    path.join(__dirname, "rules")
+  ];
+  t.deepEqual(
+    resolveModule(
+      "micromark",
+      paths
+    ),
+    require.resolve(
+      "micromark",
+      { paths }
+    )
+  );
+  t.deepEqual(
+    resolveModule(
+      "./rules/node_modules/markdownlint-rule-sample-commonjs",
+      paths
+    ),
+    require.resolve(
+      "./rules/node_modules/markdownlint-rule-sample-commonjs",
+      { paths }
+    )
+  );
+  t.deepEqual(
+    resolveModule(
+      "markdownlint-rule-sample-commonjs",
+      paths
+    ),
+    require.resolve(
+      "markdownlint-rule-sample-commonjs",
+      { paths }
+    )
+  );
+});
+
+test("custom resolve implementation", (t) => {
+  t.plan(1);
+  const expected =
+    require.resolve("./rules/node_modules/markdownlint-rule-sample-module");
+  const customResolve = (id, options) => require.resolve(id, options);
+  customResolve.paths = (request) => require.resolve.paths(request);
+  t.deepEqual(
+    resolveModuleCustomResolve(
+      customResolve,
+      "./rules/node_modules/markdownlint-rule-sample-module",
+      [ __dirname ]
+    ),
+    expected
+  );
+});
+
+test("custom resolve implementation, missing paths", (t) => {
+  t.plan(1);
+  const expected =
+    require.resolve("./rules/node_modules/markdownlint-rule-sample-commonjs");
+  const customResolve = (id, options) => require.resolve(id, options);
+  t.deepEqual(
+    resolveModuleCustomResolve(
+      // @ts-ignore
+      customResolve,
+      "./rules/node_modules/markdownlint-rule-sample-commonjs",
+      [ __dirname ]
+    ),
+    expected
+  );
+});