From a9a3140a8db9e46442bf921ea18fb34a55247871 Mon Sep 17 00:00:00 2001
From: Bertrand Marron <bertrand.marron@gmail.com>
Date: Tue, 19 Jun 2018 15:57:22 +0200
Subject: [PATCH] Stop mutating props in map component

---
 components/centered-map/enhance-map-data.js | 68 +++++++++++++++++++++
 components/centered-map/map.js              | 40 +++---------
 2 files changed, 76 insertions(+), 32 deletions(-)
 create mode 100644 components/centered-map/enhance-map-data.js

diff --git a/components/centered-map/enhance-map-data.js b/components/centered-map/enhance-map-data.js
new file mode 100644
index 000000000..00c3e6ec2
--- /dev/null
+++ b/components/centered-map/enhance-map-data.js
@@ -0,0 +1,68 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+import hoist from 'hoist-non-react-statics'
+import computeBbox from '@turf/bbox'
+import flip from '@turf/flip'
+
+import {isBboxFlipped, flipBbox} from '../../lib/geo/bbox'
+
+export default uniqueFeatureId => Map => hoist(class extends React.PureComponent {
+  static propTypes = {
+    frozen: PropTypes.bool,
+    extent: PropTypes.object,
+    data: PropTypes.shape({
+      features: PropTypes.arrayOf(PropTypes.shape({
+        properties: PropTypes.object.isRequired
+      }))
+    }).isRequired
+  }
+
+  static defaultProps = {
+    frozen: false,
+    extent: null
+  }
+
+  render() {
+    const {data, extent, frozen, ...otherProps} = this.props
+
+    let transformed = false
+    let transformedData = data
+
+    let bbox = computeBbox(transformedData)
+    if (extent) {
+      if (isBboxFlipped(bbox, computeBbox(extent))) {
+        transformed = true
+        transformedData = flip(data, {mutate: false})
+        bbox = flipBbox(bbox)
+      }
+    }
+
+    if (!frozen && uniqueFeatureId) {
+      // We’re adding a unique property to all features
+      // so that we can easily identify them later.
+
+      if (transformedData.features) {
+        if (!transformed) {
+          transformedData = {...transformedData}
+        }
+
+        transformedData.features = transformedData.features.map((feature, index) => ({
+          ...feature,
+          properties: {
+            ...feature.properties,
+            [uniqueFeatureId]: index
+          }
+        }))
+      }
+    }
+
+    return (
+      <Map
+        data={transformedData}
+        frozen={frozen}
+        bbox={bbox}
+        {...otherProps}
+      />
+    )
+  }
+}, Map)
diff --git a/components/centered-map/map.js b/components/centered-map/map.js
index d962d1198..c517a2b63 100644
--- a/components/centered-map/map.js
+++ b/components/centered-map/map.js
@@ -1,12 +1,9 @@
 import React from 'react'
 import PropTypes from 'prop-types'
 import mapboxgl from 'mapbox-gl'
-import bbox from '@turf/bbox'
-import flip from '@turf/flip'
-
 import mapStyle from 'mapbox-gl/dist/mapbox-gl.css'
 
-import {isBboxFlipped, flipBbox} from '../../lib/geo/bbox'
+import enhanceMapData from './enhance-map-data'
 
 import Feature from './feature'
 
@@ -15,13 +12,8 @@ const UNIQUE_FEATURE_ID = '$GDV_UNIQUE_FEATURE_ID$'
 class CenteredMap extends React.Component {
   static propTypes = {
     data: PropTypes.object.isRequired,
-    extent: PropTypes.object,
-    frozen: PropTypes.bool
-  }
-
-  static defaultProps = {
-    extent: null,
-    frozen: false
+    bbox: PropTypes.array.isRequired,
+    frozen: PropTypes.bool.isRequired
   }
 
   state = {
@@ -31,27 +23,9 @@ class CenteredMap extends React.Component {
   constructor(props) {
     super(props)
 
-    this.bbox = bbox(props.data)
-    if (props.extent) {
-      if (isBboxFlipped(this.bbox, bbox(props.extent))) {
-        // Even though we should never mutate a component’s props,
-        // flipped coordinates should also never appear.
-        // We’re mutating the `data` prop here (and it is faster).
-
-        flip(props.data, {mutate: true})
-        this.bbox = flipBbox(this.bbox)
-      }
-    }
-
     this.handlers = []
 
     if (!props.frozen) {
-      if (props.data.features) {
-        props.data.features.forEach((feature, index) => {
-          feature.properties[UNIQUE_FEATURE_ID] = index
-        })
-      }
-
       for (const layer of ['point', 'polygon-fill', 'line']) {
         this.handlers.push({
           event: 'mousemove',
@@ -67,7 +41,7 @@ class CenteredMap extends React.Component {
   }
 
   componentDidMount() {
-    const {frozen} = this.props
+    const {frozen, bbox} = this.props
 
     this.map = new mapboxgl.Map({
       container: this.mapContainer,
@@ -77,7 +51,7 @@ class CenteredMap extends React.Component {
 
     this.map.once('load', this.onLoad)
 
-    this.map.fitBounds(this.bbox, {
+    this.map.fitBounds(bbox, {
       padding: 30,
       linear: true,
       duration: 0
@@ -282,4 +256,6 @@ class CenteredMap extends React.Component {
   }
 }
 
-export default CenteredMap
+export default enhanceMapData(UNIQUE_FEATURE_ID)(
+  CenteredMap
+)