Added support for passing Regex into CLI (#14)

* Added support for passing Regex into CLI

This will allow for passing the `from`/`to` parameters as regex in the format `\match\g` through the CLI. If pattern does not match a Regex it will fall back to passing through as a `String`.

* - Fixed style inconsistencies
- Added -isRegex parameter to explicitly state ‘from’ parameter is a regex
- Removed regex support from ‘to’ parameter

* Replaced -isRegex with —isRegex and moved to the end of the param list

* Added line and sample syntax for CLI in README

README.md

@@ -95,14 +95,16 @@ catch (error) {
 Via CLI:
 
 ```sh
-replace-in-file from to some/file.js,some/**/glob.js
+replace-in-file from to some/file.js,some/**/glob.js [--isRegex]
 ```
 
 The options `allowEmptyPaths` and `encoding` are supported in the CLI.
 In addition, the CLI supports the `verbose` option to list the changed files.
 
 Multiple files or globs can be replaced by providing a comma separated list.
 
+A regular expression may be used for the `from` parameter by specifying the `--isRegex` option.
+
 ## License
 (MIT License)
 

bin/cli.js

@@ -15,14 +15,27 @@ if (argv._.length < 3) {
 }
 
 //Collect main arguments
-const from = argv._.shift();
+let from = argv._.shift();
 const to = argv._.shift();
 
 //Single star globs already get expanded in the command line
 const files = argv._.reduce((files, file) => {
   return files.concat(file.split(','));
 }, []);
 
+// If the --isRegex flag is passed, send the 'from' parameter
+// to the lib as a RegExp object
+if (argv.isRegex) {
+  const flags = from.replace(/.*\/([gimy]*)$/, '$1');
+  const pattern = from.replace(new RegExp(`^/(.*?)/${flags}$`), '$1');
+  try {
+    from = new RegExp(pattern, flags);
+  }
+  catch (error) {
+    console.error('Could not create RegExp from \'from\' parameter', error);
+  }
+}
+
 //Log
 console.log(`Replacing '${from}' with '${to}'`);