feat: add "AllowEmptyTargets" option (#173)

Author: mrmlnc

docs/cli.md

@@ -84,3 +84,7 @@ $ npmPkgJsonLint . --ignorePath .gitignore
 ## `--maxWarnings` (alias `-mw`)
 
 Max number of warnings that are allowed before an error is thrown. By default, npm-package-json-lint allows `10000000`.
+
+## `--allowEmptyTargets`
+
+Do not throw an error when a list of targets is empty.

src/cli.js

@@ -26,6 +26,7 @@ const cli = meow(
         --configFile, -c File path of .npmpackagejsonlintrc.json
         --ignorePath, -i Path to a file containing patterns that describe files to ignore. The path can be absolute or relative to process.cwd(). By default, npm-package-json-lint looks for .npmpackagejsonlintignore in process.cwd().
         --maxWarnings, -mw Maximum number of warnings that can be detected before an error is thrown.
+        --allowEmptyTargets Do not throw an error when a list of targets is empty.
 
       Examples
         $ npmPkgJsonLint --version
@@ -67,6 +68,10 @@ const cli = meow(
         type: 'number',
         alias: 'mw',
         default: 10000000
+      },
+      allowEmptyTargets: {
+        type: 'boolean',
+        default: false
       }
     }
   }
@@ -83,7 +88,10 @@ debug(`patterns: ${patterns}`);
 if (patterns.length === noPatternsProvided) {
   debug(`No lint targets provided`);
   console.log(chalk.red.bold('No lint targets provided'));
-  process.exit(exitCodes.oneMissingTarget);
+
+  const exitCode = cli.flags.allowEmptyTargets ? exitCodes.zeroClean : exitCodes.oneMissingTarget;
+
+  process.exit(exitCode);
 }
 
 try {

test/integration/cli.test.js

@@ -52,6 +52,7 @@ describe('cli Integration Tests', () => {
     --configFile, -c File path of .npmpackagejsonlintrc.json
     --ignorePath, -i Path to a file containing patterns that describe files to ignore. The path can be absolute or relative to process.cwd(). By default, npm-package-json-lint looks for .npmpackagejsonlintignore in process.cwd().
     --maxWarnings, -mw Maximum number of warnings that can be detected before an error is thrown.
+    --allowEmptyTargets Do not throw an error when a list of targets is empty.
 
   Examples
     $ npmPkgJsonLint --version
@@ -98,6 +99,15 @@ describe('cli Integration Tests', () => {
       expect(cli.stderr.toString()).toStrictEqual('');
       expect(cli.status).toStrictEqual(oneMissingTargets);
     });
+
+    test('should exit with zero code when an empty targets is allowed', () => {
+      const cli = spawnSync(relativePathToCli, ['--allowEmptyTargets'], {env});
+      const expected = 'No lint targets provided\n';
+
+      expect(cli.stdout.toString()).toStrictEqual(expected);
+      expect(cli.stderr.toString()).toStrictEqual('');
+      expect(cli.status).toStrictEqual(zeroClean);
+    });
   });
 
   describe('when the cli is run without quiet', () => {