Add custom stringify support

Author: TrySound

README.md

@@ -207,10 +207,12 @@ If the `quantity` argument cannot be parsed as a number, returns `false`.
 the unit. Instead, you should pass it single quantities only. Parse `1px solid black`, then pass it
 the stringified `1px` node (a `word` node) to parse the number and unit.
 
-### valueParser.stringify(nodes)
+### valueParser.stringify(nodes[, custom])
 
 Stringifies a node or array of nodes.
 
+The `custom` function is called for each `node`; return a string to override the default behaviour.
+
 ### valueParser.walk(nodes, callback[, bubble])
 
 Walks each provided node, recursively walking all descendent nodes within functions.

lib/stringify.js

@@ -1,9 +1,12 @@
-function stringifyNode(node) {
+function stringifyNode(node, custom) {
     var type = node.type;
     var value = node.value;
     var buf;
+    var customResult;
 
-    if (type === 'word' || type === 'space') {
+    if (custom && (customResult = custom(node)) !== undefined) {
+        return customResult;
+    } else if (type === 'word' || type === 'space') {
         return value;
     } else if (type === 'string') {
         buf = node.quote || '';
@@ -22,17 +25,17 @@ function stringifyNode(node) {
     return value;
 }
 
-function stringify(nodes) {
+function stringify(nodes, custom) {
     var result, i;
 
     if (Array.isArray(nodes)) {
         result = '';
         for (i = nodes.length - 1; ~i; i -= 1) {
-            result = stringifyNode(nodes[i]) + result;
+            result = stringifyNode(nodes[i], custom) + result;
         }
         return result;
     }
-    return stringifyNode(nodes);
+    return stringifyNode(nodes, custom);
 }
 
 module.exports = stringify;

package.json

@@ -22,7 +22,8 @@
       "max-len": 0,
       "no-bitwise": 0,
       "complexity": 0,
-      "no-use-before-define": 0
+      "no-use-before-define": 0,
+      "consistent-return": 0
     }
   },
   "author": "Bogdan Chadkin <trysound@yandex.ru>",

test/stringify.js

@@ -34,14 +34,34 @@ var tests = [
 ];
 
 test('Stringify', function (t) {
-    t.plan(tests.length + 1);
+    t.plan(tests.length + 3);
 
     tests.forEach(function (opts) {
         t.equal(stringify(parse(opts.fixture)), opts.fixture, opts.message);
     });
 
     var tokens = parse(' rgba(12,  54, 65 ) ');
-    tokens[1].type = 'word';
 
+    t.equal(stringify(tokens, function (node) {
+        if (node.type === 'function') {
+            return node.value + '[' + [
+                node.nodes[0].value,
+                node.nodes[2].value,
+                node.nodes[4].value
+            ].join(',') + ']';
+        }
+    }), ' rgba[12,54,65] ');
+
+    t.equal(stringify(tokens[1], function (node) {
+        if (node.type === 'function') {
+            return node.value + '[' + [
+                node.nodes[0].value,
+                node.nodes[2].value,
+                node.nodes[4].value
+            ].join(',') + ']';
+        }
+    }), 'rgba[12,54,65]');
+
+    tokens[1].type = 'word';
     t.equal(stringify(tokens), ' rgba ', 'Shouldn\'t process nodes of work type');
 });