Add support for .markdownlintignore file (fixes #61).

Author: DavidAnson

README.md

@@ -36,17 +36,28 @@ With shells like Bash, it may be necessary to quote globs so they are not interp
 For example, `--ignore *.md` would be expanded by Bash to `--ignore a.md b.md ...` before invoking `markdownlint-cli`, causing it to ignore only the first file because `--ignore` takes a single parameter (though it can be used multiple times).
 Quoting the glob like `--ignore '*.md'` passes it through unexpanded and ignores the set of files.
 
-#### Examples
+#### Globbing examples
 
 To lint all Markdown files in a Node.js project (excluding dependencies), the following commands might be used:
 
 Windows CMD: `markdownlint **/*.md --ignore node_modules`
 
 Linux Bash: `markdownlint '**/*.md' --ignore node_modules`
 
+### Ignoring files
+
+If present in the current folder, a `.markdownlintignore` file will be used to ignore files and /or directories according to the rules for [gitignore][gitignore].
+
+The order of operations is:
+
+- Enumerate files/directories/globs on the command line
+- Apply exclusions from `.markdownlintignore`
+- Apply exclusions from `-i`/`--ignore` option(s)
+
 ### Fixing errors
 
-When the `--fix` option is specified, `markdownlint-cli` tries to apply all fixes reported by the active rules and reports any errors that remain. Because this option makes changes to the input files, it is good to make a backup first or work with files under source control so any unwanted changes can be undone.
+When the `--fix` option is specified, `markdownlint-cli` tries to apply all fixes reported by the active rules and reports any errors that remain.
+Because this option makes changes to the input files, it is good to make a backup first or work with files under source control so any unwanted changes can be undone.
 
 > Because not all rules include fix information when reporting errors, fixes may overlap, and not all errors are fixable, `--fix` will not usually address all errors.
 
@@ -70,12 +81,16 @@ The example of configuration file:
 
 See [test configuration file][test-config] or [style folder][style-folder] for more examples.
 
-CLI argument `--config` is not mandatory. If it is not provided, `markdownlint-cli` looks for file `.markdownlint.json`/`.markdownlint.yaml`/`.markdownlint.yml` in current folder, or for file `.markdownlintrc` in current or all upper folders. The algorithm is described in details on [rc package page][rc-standards]. If `--config` argument is provided, the file must be valid JSON, JSONC, or YAML.
+CLI argument `--config` is not mandatory.
+If it is not provided, `markdownlint-cli` looks for file `.markdownlint.json`/`.markdownlint.yaml`/`.markdownlint.yml` in current folder, or for file `.markdownlintrc` in current or all upper folders.
+The algorithm is described in details on [rc package page][rc-standards].
+If `--config` argument is provided, the file must be valid JSON, JSONC, or YAML.
 
 ## Related
 
 - [markdownlint][markdownlint] - API for this module
 - [glob][glob] - Pattern matching implementation
+- [ignore][ignore] - `.markdownlintignore` implementation
 
 ## License
 
@@ -95,3 +110,5 @@ MIT © Igor Shubovych
 [rc-standards]: https://www.npmjs.com/package/rc#standards
 [glob]: https://github.com/isaacs/node-glob
 [globprimer]: https://github.com/isaacs/node-glob/blob/master/README.md#glob-primer
+[ignore]: https://github.com/kaelzhang/node-ignore
+[gitignore]: https://git-scm.com/docs/gitignore

markdownlint.js

@@ -12,6 +12,7 @@ const jsoncParser = require('jsonc-parser');
 const differenceWith = require('lodash.differencewith');
 const flatten = require('lodash.flatten');
 const extend = require('deep-extend');
+const ignore = require('ignore');
 const markdownlint = require('markdownlint');
 const markdownlintRuleHelpers = require('markdownlint-rule-helpers');
 const rc = require('rc');
@@ -29,6 +30,7 @@ const projectConfigFiles = [
   '.markdownlint.yml'
 ];
 const configFileParsers = [jsoncParse, jsYaml.safeLoad];
+const fsOptions = {encoding: 'utf8'};
 
 function readConfiguration(args) {
   let config = rc('markdownlint', {});
@@ -214,7 +216,16 @@ function loadCustomRules(rules) {
   }));
 }
 
-const files = prepareFileList(program.args, ['md', 'markdown']);
+const markdownlintIgnore = '.markdownlintignore';
+let ignoreFilter = () => true;
+if (fs.existsSync(markdownlintIgnore)) {
+  const ignoreText = fs.readFileSync(markdownlintIgnore, fsOptions);
+  const ignoreInstance = ignore().add(ignoreText);
+  ignoreFilter = fileInfo => !ignoreInstance.ignores(fileInfo.original);
+}
+
+const files = prepareFileList(program.args, ['md', 'markdown'])
+  .filter(ignoreFilter);
 const ignores = prepareFileList(program.ignore, ['md', 'markdown'], files);
 const customRules = loadCustomRules(program.rules);
 const diff = differenceWith(files, ignores, function (a, b) {
@@ -242,7 +253,6 @@ function lintAndPrint(stdin, files) {
       ...lintOptions,
       resultVersion: 3
     };
-    const fsOptions = {encoding: 'utf8'};
     files.forEach(file => {
       fixOptions.files = [file];
       const fixResult = markdownlint.sync(fixOptions);

package.json

@@ -41,6 +41,7 @@
     "deep-extend": "~0.5.1",
     "get-stdin": "~5.0.1",
     "glob": "~7.1.2",
+    "ignore": "~5.1.4",
     "js-yaml": "~3.13.1",
     "jsonc-parser": "~2.2.0",
     "lodash.differencewith": "~4.5.0",

test/markdownlintignore/.markdownlintignore

@@ -0,0 +1,6 @@
+# comment followed by blank line
+
+# star-star pattern with trailing space
+**/*.markdown 
+# negated star pattern
+!subd*/incorrect.markdown

test/markdownlintignore/correct.md

@@ -0,0 +1 @@
+# header

test/markdownlintignore/incorrect.markdown

@@ -0,0 +1 @@
+# header

test/markdownlintignore/incorrect.md

@@ -0,0 +1 @@
+# header

test/markdownlintignore/subdir/incorrect.markdown

@@ -0,0 +1 @@
+# header

test/test.js

@@ -106,7 +106,7 @@ test('glob linting works with failing files', async t => {
     t.fail();
   } catch (error) {
     t.deepEqual(error.stdout, '');
-    t.deepEqual(error.stderr.match(errorPattern).length, 16);
+    t.deepEqual(error.stderr.match(errorPattern).length, 17);
   }
 });
 
@@ -166,7 +166,7 @@ test('glob linting with failing files has fewer errors when ignored by dir', asy
     t.fail();
   } catch (error) {
     t.deepEqual(error.stdout, '');
-    t.deepEqual(error.stderr.match(errorPattern).length, 8);
+    t.deepEqual(error.stderr.match(errorPattern).length, 9);
   }
 });
 
@@ -178,7 +178,7 @@ test('glob linting with failing files has fewer errors when ignored by dir and a
     t.fail();
   } catch (error) {
     t.deepEqual(error.stdout, '');
-    t.deepEqual(error.stderr.match(errorPattern).length, 8);
+    t.deepEqual(error.stderr.match(errorPattern).length, 9);
   }
 });
 
@@ -626,3 +626,22 @@ test('fixing errors with a glob yields fewer errors', async t => {
     fs.unlinkSync(fixSubFileC);
   }
 });
+
+test('.markdownlintignore is applied correctly', async t => {
+  try {
+    await execa(
+      path.resolve('..', 'markdownlint.js'), ['.'], {
+        cwd: path.join(__dirname, 'markdownlintignore'),
+        stripFinalNewline: false
+      });
+    t.fail();
+  } catch (error) {
+    const expected = [
+      'incorrect.md:1 MD047/single-trailing-newline Files should end with a single newline character',
+      'subdir/incorrect.markdown:1 MD047/single-trailing-newline Files should end with a single newline character',
+      ''
+    ].join('\n');
+    t.deepEqual(error.stdout, '');
+    t.deepEqual(error.stderr, expected);
+  }
+});