feat: Exit the process with 0 (success) if no files were found and --succeed-with-no-files was requested

Fixes #20.

Author: prantlf

README.md

@@ -160,6 +160,7 @@ Usage: `jsonlint [options] [--] [<file, directory, pattern> ...]`
     --enforce-double-quotes      surrounds all strings with double quotes
     --enforce-single-quotes      surrounds all strings with single quotes
     --trim-trailing-commas       omit trailing commas from objects and arrays
+    --succeed-with-no-files      succeed (exit code 0) if no files were found
     -v, --version                output the version number
     -h, --help                   display help for command
 

lib/cli.js

@@ -57,6 +57,7 @@ Options:
   --enforce-double-quotes      surrounds all strings with double quotes
   --enforce-single-quotes      surrounds all strings with single quotes
   --trim-trailing-commas       omit trailing commas from objects and arrays
+  --succeed-with-no-files      succeed (exit code 0) if no files were found
   -v, --version                output the version number
   -h, --help                   display help for command
 
@@ -208,6 +209,9 @@ for (let i = 2, l = argv.length; i < l; ++i) {
         case 'trim-trailing-commas':
           params.trimTrailingCommas = flag
           return
+        case 'succeed-with-no-files':
+          params.succeedWithNoFiles = flag
+          return
         case 'v': case 'version':
           console.log(require('../package.json').version)
           process.exit(0)
@@ -532,7 +536,7 @@ function processPatterns (patterns) {
   const files = sync(patterns, { onlyFiles: true })
   if (!files.length) {
     console.error('no files found')
-    process.exit(1)
+    process.exit(params.succeedWithNoFiles ? 0 : 1)
   }
   for (const file of files) {
     try {