Implement parser name "auto" and choose that for unkown parsers

Author: Ruben Bridgewater

README.md

@@ -30,7 +30,7 @@ new Parser(options);
 * `returnError`: *function*; mandatory
 * `returnFatalError`: *function*; optional, defaults to the returnError function
 * `returnBuffers`: *boolean*; optional, defaults to false
-* `name`: *javascript|hiredis*; optional, defaults to hiredis and falls back to the js parser if not available or if the stringNumbers option is choosen
+* `name`: *'javascript'|'hiredis'|'auto'|null*; optional, defaults to hiredis and falls back to the js parser if not available or if the stringNumbers option is choosen. Setting this to 'auto' or null is going to automatically determine what parser is available and chooses that one.
 * `stringNumbers`: *boolean*; optional, defaults to false. This is only available for the javascript parser at the moment!
 
 ### Example
@@ -55,8 +55,9 @@ var parser = new Parser({
     },
     returnFatalError: function (err) {
         lib.returnFatalError(err);
-    }
-}); // This returns either a hiredis or the js parser instance depending on what's available
+    },
+    name: 'auto' // This returns either the hiredis or the js parser instance depending on what's available
+});
 
 Library.prototype.streamHandler = function () {
     this.stream.on('data', function (buffer) {

changelog.md

@@ -1,3 +1,10 @@
+## v.1.3.0 - 27 Mar, 2016
+
+Features
+
+-  Added `auto` as parser name option to check what parser is available
+-  Non existing requested parsers falls back into auto mode instead of always choosing the JS parser
+
 ## v.1.2.0 - 27 Mar, 2016
 
 Features

lib/parser.js

@@ -20,20 +20,19 @@ function Parser (options) {
         throw new Error('Please provide all return functions while initiating the parser');
     }
 
-    /* istanbul ignore if: hiredis should always be installed while testing */
     if (options.name === 'hiredis') {
+        /* istanbul ignore if: hiredis should always be installed while testing */
         if (!parsers.hiredis) {
             msg = 'You explicitly required the hiredis parser but hiredis is not installed. The JS parser is going to be returned instead.';
         } else if (options.stringNumbers) {
             msg = 'You explicitly required the hiredis parser in combination with the stringNumbers option. Only the JS parser can handle that and is choosen instead.';
         }
-    } else if (options.name && !parsers[options.name]) {
-        msg = 'The requested parser "' + options.name + '" is unkown and the JS parser is choosen instead.';
+    } else if (options.name && !parsers[options.name] && options.name !== 'auto') {
+        msg = 'The requested parser "' + options.name + '" is unkown and the default parser is choosen instead.';
     }
 
     if (msg) {
         console.warn(new Error(msg).stack.replace('Error: ', 'Warning: '));
-        options.name = 'javascript';
     }
 
     options.name = options.name || 'hiredis';

test/parsers.spec.js

@@ -23,6 +23,24 @@ describe('parsers', function () {
             assert.strictEqual(parser.name, 'hiredis');
         });
 
+        it('auto parser', function () {
+            var parser = new Parser({
+                returnReply: returnReply,
+                returnError: returnError,
+                name: 'auto'
+            });
+            assert.strictEqual(parser.name, 'hiredis');
+        });
+
+        it('auto parser v2', function () {
+            var parser = new Parser({
+                returnReply: returnReply,
+                returnError: returnError,
+                name: null
+            });
+            assert.strictEqual(parser.name, 'hiredis');
+        });
+
         it('fail for missing options', function () {
             assert.throws(function() {
                 new Parser({
@@ -42,13 +60,14 @@ describe('parsers', function () {
                 str += data;
                 return '';
             });
-            new Parser({
+            var parser = new Parser({
                 returnReply: returnReply,
                 returnError: returnError,
                 name: 'something_unknown'
             });
             unhookIntercept();
-            assert(/^Warning: The requested parser "something_unknown" is unkown and the JS parser is choosen instead\.\n +at new Parser/.test(str), str);
+            assert.strictEqual(parser.name, 'hiredis');
+            assert(/^Warning: The requested parser "something_unknown" is unkown and the default parser is choosen instead\.\n +at new Parser/.test(str), str);
         });
 
         it('hiredis and stringNumbers', function () {
@@ -57,13 +76,14 @@ describe('parsers', function () {
                 str += data;
                 return '';
             });
-            new Parser({
+            var parser = new Parser({
                 returnReply: returnReply,
                 returnError: returnError,
                 name: 'hiredis',
                 stringNumbers: true
             });
             unhookIntercept();
+            assert.strictEqual(parser.name, 'javascript');
             assert(/^Warning: You explicitly required the hiredis parser in combination with the stringNumbers option. .+.\.\n +at new Parser/.test(str), str);
         });