* [jsfm] fix when the key of trackby is zero

src/js-framework/lib/__test__/assets/repeat-watch.input

@@ -0,0 +1,59 @@
+define('@weex-component/04f1048c50eca3454bc70de93d3213d4', function(require, exports, module) {
+
+    ;
+    module.exports = {
+        data: function() {
+            return {
+                list: [{
+                    text: 1
+                }, {
+                    text: 2
+                }],
+                more: [{
+                    text: 3
+                }]
+            }
+        },
+        ready: function() {
+            for (var i = 0; i < this.more.length; i++) {
+                this.list.push(this.more[i]);
+            }
+            this._app.updateActions()
+        }
+
+    }
+
+
+    ;
+    module.exports.style = {}
+
+    ;
+    module.exports.template = {
+        "type": "list",
+        "children": [{
+            "type": "cell",
+            "append": "tree",
+            "repeat": function() {
+                return this.list
+            },
+            "children": [{
+                "type": "text",
+                "style": {
+                    "height": 600
+                },
+                "attr": {
+                    "value": function() {
+                        return this.text
+                    }
+                }
+            }]
+        }]
+    }
+
+    ;
+})
+
+// require module
+bootstrap('@weex-component/04f1048c50eca3454bc70de93d3213d4', {
+    "transformerVersion": "0.3.1"
+})

src/js-framework/lib/__test__/assets/repeat-watch.output

@@ -0,0 +1,46 @@
+{
+    "type": "list",
+    "children": [{
+        "type": "cell",
+        "attr": {
+            "append": "tree"
+        },
+        "children": [{
+            "type": "text",
+            "attr": {
+                "value": 1
+            },
+            "style": {
+                "height": 600
+            }
+        }]
+    }, {
+        "type": "cell",
+        "attr": {
+            "append": "tree"
+        },
+        "children": [{
+            "type": "text",
+            "attr": {
+                "value": 2
+            },
+            "style": {
+                "height": 600
+            }
+        }]
+    }, {
+        "type": "cell",
+        "attr": {
+            "append": "tree"
+        },
+        "children": [{
+            "type": "text",
+            "attr": {
+                "value": 3
+            },
+            "style": {
+                "height": 600
+            }
+        }]
+    }]
+}

src/js-framework/lib/__test__/test.js

@@ -529,6 +529,22 @@ describe('test input and output', function () {
     delete allDocs[name]
   })
 
+  it('repeat-watch case', function () {
+    var name = 'repeat-watch'
+    var inputCode = readInput(name)
+    var outputCode = readOutput(name)
+    var doc = new Document(name)
+    allDocs[name] = doc
+
+    framework.createInstance(name, inputCode)
+    var expected = eval('(' + outputCode + ')')
+    var actual = doc.toJSON()
+    expect(actual).eql(expected)
+
+    framework.destroyInstance(name)
+    delete allDocs[name]
+  })
+
   it('if-refresh case', function () {
     var name = 'if-refresh'
     var inputCode = readInput(name)

src/js-framework/lib/vm/compiler.js

@@ -412,7 +412,8 @@ export function _bindRepeat(target, fragBlock, info) {
       const reusedMap = {}
       data.forEach((item, index) => {
         const key = trackBy ? item[trackBy] : index
-        if (!key) {
+        /* istanbul ignore if */
+        if (key == null || key === '') {
           return
         }
         trackMap[key] = item