Remove duplicated features from popups (#41)

src/components/map/FeaturePropertyPopup.jsx

@@ -23,7 +23,7 @@ function renderProperties(feature) {
 
 function renderFeature(feature) {
   return <div key={feature.id}>
-    <div className="maputnik-popup-layer-id">{feature.layer['source-layer']}</div>
+    <div className="maputnik-popup-layer-id">{feature.layer['source-layer']}{feature.inspectModeCounter && <span> × {feature.inspectModeCounter}</span>}</div>
     <InputBlock key={"property-type"} label={"$type"}>
       <StringInput value={feature.geometry.type} style={{backgroundColor: 'transparent'}} />
     </InputBlock>
@@ -31,13 +31,36 @@ function renderFeature(feature) {
   </div>
 }
 
+function removeDuplicatedFeatures(features) {
+  let uniqueFeatures = [];
+
+  features.forEach(feature => {
+    const featureIndex = uniqueFeatures.findIndex(feature2 => {
+      return feature.layer['source-layer'] === feature2.layer['source-layer'] 
+        && JSON.stringify(feature.properties) === JSON.stringify(feature2.properties)
+    })
+
+    if(featureIndex === -1) {
+      uniqueFeatures.push(feature)
+    } else {
+      if(uniqueFeatures[featureIndex].hasOwnProperty('counter')) {
+        uniqueFeatures[featureIndex].inspectModeCounter++
+      } else {
+        uniqueFeatures[featureIndex].inspectModeCounter = 2
+      }
+    }
+  })
+
+  return uniqueFeatures
+}
+
 class FeaturePropertyPopup extends React.Component {
   static propTypes = {
     features: PropTypes.array
   }
 
   render() {
-    const features = this.props.features
+    const features = removeDuplicatedFeatures(this.props.features)
     return <div className="maputnik-feature-property-popup">
       {features.map(renderFeature)}
     </div>