Merge pull request #9 from deltamualpha/master

Don't attempt to parse a file if the key already exists in the metadata, even if the file is missing

lib/index.js

@@ -36,19 +36,21 @@ function plugin(opts){
       var file = opts[key];
       var ext = extname(file);
       if (!~exts.indexOf(ext)) throw new Error('unsupported metadata type "' + ext + '"');
-      if (!files[file]) throw new Error('file "' + file + '" not found');
+      if (!metadata[key] || files[file]) {
+        if (!files[file]) throw new Error('file "' + file + '" not found');
 
-      var parse = parsers[ext];
-      var str = files[file].contents.toString();
-      delete files[file];
+        var parse = parsers[ext];
+        var str = files[file].contents.toString();
+        delete files[file];
 
-      try {
-        var data = parse(str);
-      } catch (e) {
-        return done(new Error('malformed data in "' + file + '"'));
-      }
+        try {
+          var data = parse(str);
+        } catch (e) {
+          return done(new Error('malformed data in "' + file + '"'));
+        }
 
-      metadata[key] = data;
+        metadata[key] = data;
+      }
     }
 
     done();

test/fixtures/duplicate/src/data.json

@@ -0,0 +1,3 @@
+{
+  "string": "string"
+}

test/fixtures/duplicate/src/data2.json

@@ -0,0 +1,3 @@
+{
+  "string": "string2"
+}

test/index.js

@@ -25,6 +25,30 @@ describe('metalsmith-metadata', function(){
     });
   });
 
+  it('should not parse a file if the key already exists in the metadata', function(done){
+    var m = Metalsmith('test/fixtures/json')
+      .use(metadata({ file: 'data.json' }))
+      .use(metadata({ file: 'missing.json' }));
+    m.build(function(err){
+      if (err) return done(err);
+      assert.deepEqual(m.metadata().file, { string: 'string' });
+      assert(!exists('test/fixtures/json/build'));
+      done();
+    });
+  });
+
+  it('should parse a file even if the key exists if the file is in the bundle', function(done){
+    var m = Metalsmith('test/fixtures/duplicate')
+      .use(metadata({ file: 'data.json' }))
+      .use(metadata({ file: 'data2.json' }));
+    m.build(function(err){
+      if (err) return done(err);
+      assert.deepEqual(m.metadata().file, { string: 'string2' });
+      assert(!exists('test/fixtures/json/build'));
+      done();
+    });
+  });
+
   it('should parse YAML', function(done){
     var m = Metalsmith('test/fixtures/yaml').use(metadata({ file: 'data.yaml' }));
     m.build(function(err){