From e785e42dbb0947bf3d510db6a3ccfea21416813c Mon Sep 17 00:00:00 2001
From: David Anson <david@dlaa.me>
Date: Sun, 28 Jan 2024 05:11:48 +0000
Subject: [PATCH] Make scoped custom rule package identifiers work with the
 --rules parameter (fixes #449).

---
 .gitignore                                        |  1 +
 markdownlint.js                                   |  2 +-
 .../node_modules/@scoped/custom-rule/package.json |  6 ++++++
 .../@scoped/custom-rule/scoped-rule.cjs           | 10 ++++++++++
 test/custom-rules/scoped-package/scoped-test.md   |  1 +
 test/test.js                                      | 15 +++++++++++++++
 6 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/package.json
 create mode 100644 test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/scoped-rule.cjs
 create mode 100644 test/custom-rules/scoped-package/scoped-test.md

diff --git a/.gitignore b/.gitignore
index 5658f8a4f..99e24c745 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,6 +28,7 @@ build/Release
 node_modules
 # Keep it for test
 !test/custom-rules/relative-to-cwd/node_modules
+!test/custom-rules/scoped-package/node_modules
 
 # Optional npm cache directory
 .npm
diff --git a/markdownlint.js b/markdownlint.js
index 708a3b78e..46b3cb8bb 100755
--- a/markdownlint.js
+++ b/markdownlint.js
@@ -199,7 +199,7 @@ program.parse(process.argv);
 
 function tryResolvePath(filepath) {
   try {
-    if (path.basename(filepath) === filepath && path.extname(filepath) === '') {
+    if ((path.basename(filepath) === filepath || filepath.startsWith('@')) && path.extname(filepath) === '') {
       // Looks like a package name, resolve it relative to cwd
       // Get list of directories, where requested module can be.
       let paths = Module._nodeModulePaths(processCwd);
diff --git a/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/package.json b/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/package.json
new file mode 100644
index 000000000..0925b0159
--- /dev/null
+++ b/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "markdownlint-cli-test-scoped-package-rule",
+  "main": "./scoped-rule.cjs",
+  "version": "0.0.1",
+  "private": true
+}
diff --git a/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/scoped-rule.cjs b/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/scoped-rule.cjs
new file mode 100644
index 000000000..e92d49ae8
--- /dev/null
+++ b/test/custom-rules/scoped-package/node_modules/@scoped/custom-rule/scoped-rule.cjs
@@ -0,0 +1,10 @@
+module.exports = {
+  names: ['scoped-rule'],
+  description: 'Scoped rule',
+  tags: ['test'],
+  function: (_, onError) => {
+    onError({
+      lineNumber: 1
+    });
+  }
+};
diff --git a/test/custom-rules/scoped-package/scoped-test.md b/test/custom-rules/scoped-package/scoped-test.md
new file mode 100644
index 000000000..07d82ef3a
--- /dev/null
+++ b/test/custom-rules/scoped-package/scoped-test.md
@@ -0,0 +1 @@
+# Scoped Test
diff --git a/test/test.js b/test/test.js
index 8253c25f8..682385908 100644
--- a/test/test.js
+++ b/test/test.js
@@ -535,6 +535,21 @@ test('Custom rule from node_modules package loaded relative to cwd', async t =>
   }
 });
 
+test('Custom rule with scoped package name via --rules', async t => {
+  try {
+    await execa(path.resolve('..', 'markdownlint.js'), ['--rules', '@scoped/custom-rule', 'scoped-test.md'], {
+      cwd: path.join(__dirname, 'custom-rules', 'scoped-package'),
+      stripFinalNewline: false
+    });
+    t.fail();
+  } catch (error) {
+    const expected = ['scoped-test.md:1 scoped-rule Scoped rule', ''].join('\n');
+    t.is(error.stdout, '');
+    t.is(error.stderr, expected);
+    t.is(error.exitCode, 1);
+  }
+});
+
 test('Custom rule from package loaded', async t => {
   try {
     const input = '# Input\n';