Add --enable and --disable CLI flags (fixes #214)

README.md

@@ -26,19 +26,20 @@ markdownlint --help
   MarkdownLint Command Line Interface
 
   Options:
-
-    -h, --help                                  output usage information
     -V, --version                               output the version number
     -c, --config [configFile]                   configuration file (JSON, JSONC, JS, or YAML)
     -d, --dot                                   include files/folders with a dot (for example `.github`)
     -f, --fix                                   fix basic errors (does not work with STDIN)
-    -i, --ignore [file|directory|glob]          file(s) to ignore/exclude
+    -i, --ignore [file|directory|glob]          file(s) to ignore/exclude (default: [])
     -j, --json                                  write issues in json format
     -o, --output [outputFile]                   write issues to file (no console)
     -p, --ignore-path [file]                    path to file with ignore pattern(s)
     -q, --quiet                                 do not write issues to STDOUT
-    -r, --rules  [file|directory|glob|package]  custom rule files
+    -r, --rules  [file|directory|glob|package]  include custom rule files (default: [])
     -s, --stdin                                 read from STDIN (does not work with files)
+    --enable [rules...]                         Enable certain rules, e.g. --enable MD013 MD041
+    --disable [rules...]                        Disable certain rules, e.g. --disable MD013 MD041
+    -h, --help                                  display help for command
 ```
 
 ### Globbing
@@ -101,6 +102,9 @@ If the `--config` argument is provided, the file must be valid JSON, JSONC, JS,
 JS configuration files contain JavaScript code, must have the `.js` extension, and must export (via `module.exports = ...`) a configuration object of the form shown above.
 A JS configuration file may internally `require` one or more npm packages as a way of reusing configuration across projects.
 
+`--enable` and `--disable` override configuration files; if a configuration file disables `MD002` and you pass `--enable MD002`, it will be enabled.
+If a rule is passed to both `--enable` and `--disable`, it will be disabled.
+
 > JS configuration files must be provided via the `--config` argument; they are not automatically loaded because running untrusted code is a security concern.
 
 ## Exit codes

markdownlint.js

@@ -216,8 +216,10 @@ program
   .option('-o, --output [outputFile]', 'write issues to file (no console)')
   .option('-p, --ignore-path [file]', 'path to file with ignore pattern(s)')
   .option('-q, --quiet', 'do not write issues to STDOUT')
-  .option('-r, --rules  [file|directory|glob|package]', 'custom rule files', concatArray, [])
-  .option('-s, --stdin', 'read from STDIN (does not work with files)');
+  .option('-r, --rules  [file|directory|glob|package]', 'include custom rule files', concatArray, [])
+  .option('-s, --stdin', 'read from STDIN (does not work with files)')
+  .option('--enable [rules...]', 'Enable certain rules, e.g. --enable MD013 MD041')
+  .option('--disable [rules...]', 'Disable certain rules, e.g. --disable MD013 MD041');
 
 program.parse(process.argv);
 
@@ -291,6 +293,16 @@ const diff = differenceWith(files, ignores, function (a, b) {
 function lintAndPrint(stdin, files) {
   files = files || [];
   const config = readConfiguration(options.config);
+
+  for (const rule of options.enable || []) {
+    // leave default values in place if rule is an object
+    if (!config[rule]) {
+      config[rule] = true;
+    }
+  }
+  for (const rule of options.disable || []) {
+    config[rule] = false;
+  }
   const lintOptions = {
     config,
     customRules,

test/default-false-config.yml

@@ -0,0 +1 @@
+default: false

test/test.js

@@ -851,3 +851,72 @@ test('with --quiet option does not print to stdout or stderr', async t => {
     t.is(error.exitCode, 1)
   }
 });
+
+test('--enable flag', async t => {
+  try {
+    await execa('../markdownlint.js',
+      ['--enable', 'MD002', '--config', 'default-false-config.yml', 'incorrect.md'],
+      {stripFinalNewline: false});
+    t.fail();
+  } catch (error) {
+    t.is(error.stdout, '');
+    t.is(error.stderr, 'incorrect.md:1 MD002/first-heading-h1/first-header-h1 First heading should be a top-level heading [Expected: h1; Actual: h2]\n');
+    t.is(error.exitCode, 1)
+  }
+});
+
+test('--enable flag does not modify already enabled rules', async t => {
+  try {
+    await execa('../markdownlint.js',
+      ['--enable', 'MD043', '--config', 'md043-config.yaml', 'correct.md'],
+      {stripFinalNewline: false});
+    t.fail();
+  } catch (error) {
+    t.is(error.stdout, '');
+    t.is(error.stderr, 'correct.md:1 MD043/required-headings/required-headers Required heading structure [Expected: # First; Actual: # header]\n');
+    t.is(error.exitCode, 1)
+  }
+});
+
+test('--enable flag accepts rule alias', async t => {
+  try {
+    await execa('../markdownlint.js',
+      ['--enable', 'first-header-h1', '--config', 'default-false-config.yml', 'incorrect.md'],
+      {stripFinalNewline: false});
+    t.fail();
+  } catch (error) {
+    t.is(error.stdout, '');
+    t.is(error.stderr, 'incorrect.md:1 MD002/first-heading-h1/first-header-h1 First heading should be a top-level heading [Expected: h1; Actual: h2]\n');
+    t.is(error.exitCode, 1)
+  }
+});
+
+test('--disable flag', async t => {
+  const result = await execa('../markdownlint.js',
+  ['--disable', 'MD002', 'MD014', 'MD022', 'MD041', '--', 'incorrect.md'],
+  {stripFinalNewline: false});
+
+  t.is(result.stdout, '');
+  t.is(result.stderr, '');
+  t.is(result.exitCode, 0)
+
+  try {
+    await execa('../markdownlint.js',
+      ['--disable', 'MD014', 'MD014', 'MD022', '--', 'incorrect.md'],
+      {stripFinalNewline: false});
+    t.fail();
+  } catch (error) {
+    t.is(error.stdout, '');
+    t.is(error.stderr, 'incorrect.md:1 MD041/first-line-heading/first-line-h1 First line in a file should be a top-level heading [Context: "## header 2"]\n');
+    t.is(error.exitCode, 1)
+  }
+});
+
+test('--disable flag overrides --enable flag', async t => {
+  const result = await execa('../markdownlint.js',
+    ['--disable', 'MD002', '--enable', 'MD002', '--config', 'default-false-config.yml', 'incorrect.md'],
+    {stripFinalNewline: false});
+  t.is(result.stdout, '');
+  t.is(result.stderr, '');
+  t.is(result.exitCode, 0)
+});