Change GeoJSON geometry when tag suggests area feature

app/screens/Features/AddFeatureDetail.js

@@ -26,13 +26,13 @@ import { getParentPreset } from '../../utils/get-parent-preset'
 import { colors } from '../../style/variables'
 import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view'
 import { modes } from '../../utils/map-modes'
+import { osmTagSuggestingArea } from '../../utils/osm-tag-suggesting-area'
 
 const FieldsList = styled.FlatList`
 `
 const ScrollView = styled.ScrollView`
   background-color: white
 `
-
 class EditFeatureDetail extends React.Component {
   static navigationOptions = ({ navigation }) => {
     return {
@@ -151,7 +151,7 @@ class EditFeatureDetail extends React.Component {
     feature.properties = this.getFeatureProperties()
 
     // call addFeature action with feature
-    this.props.addFeature(feature, comment)
+    this.props.addFeature(this.setGeometryFromTags(feature), comment)
 
     // call action to attempt to upload the edit
     this.props.uploadEdits([feature.id])
@@ -170,6 +170,42 @@ class EditFeatureDetail extends React.Component {
     return _omitBy(props, prop => !prop)
   }
 
+  setGeometryFromTags (feature) {
+    const { geometry } = feature
+
+    // Do not update feature of type 'Point'
+    if (geometry.type === 'Point') return feature
+
+    // Check for area tags
+    const tags = _omit(feature.properties, ['id', 'version', 'ndrefs'])
+    const areaTags = osmTagSuggestingArea(tags)
+
+    // Area tags were found and feature is LineString, change to Polygon
+    if (areaTags && geometry.type === 'LineString') {
+      return {
+        ...feature,
+        geometry: {
+          type: 'Polygon',
+          coordinates: [geometry.coordinates]
+        }
+      }
+    }
+
+    // Area tags were NOT found and feature is Polygon, change to LineString
+    if (!areaTags && feature.type === 'Polygon') {
+      return {
+        ...feature,
+        geometry: {
+          type: 'LineString',
+          coordinates: geometry.coordinates[0]
+        }
+      }
+    }
+
+    // Feature type should consistent with tags, return unchanged
+    return feature
+  }
+
   willBlur () {
     this.resetState()
   }

app/utils/osm-tag-suggesting-area.js

@@ -0,0 +1,98 @@
+import { presets as allPresets } from '../presets/presets.json'
+import presetsObjectToArray from './object-to-array'
+
+// This module is based on the approach of iD editor:
+// https://github.com/openstreetmap/iD/blob/7b09b6c0dcd193af04926727b820f346a1d86ca8/modules/osm/tags.js#L17
+
+const presetsArray = presetsObjectToArray(allPresets)
+
+/**
+ * Create a reference object with tags suggesting an area
+ */
+function getAreaTags () {
+  // The ignore list is for keys that imply lines. (We always add `area=yes` for exceptions)
+  const ignore = [
+    'barrier',
+    'highway',
+    'footway',
+    'railway',
+    'junction',
+    'type'
+  ]
+  let areaKeys = {}
+
+  // ignore name-suggestion-index and deprecated presets
+  const presets = presetsArray.filter((p) => !p.suggestion && !p.replacement)
+
+  // keeplist
+  presets.forEach((p) => {
+    let key
+    for (key in p.tags) break // pick the first tag
+    if (!key) return
+    if (ignore.indexOf(key) !== -1) return
+
+    if (p.geometry.indexOf('area') !== -1) {
+      // probably an area..
+      areaKeys[key] = areaKeys[key] || {}
+    }
+  })
+
+  // discardlist
+  presets.forEach((p) => {
+    let key
+    for (key in p.addTags) {
+      // examine all addTags to get a better sense of what can be tagged on lines - #6800
+      const value = p.addTags[key]
+      if (
+        key in areaKeys && // probably an area...
+        p.geometry.indexOf('line') !== -1 && // but sometimes a line
+        value !== '*'
+      ) {
+        areaKeys[key][value] = true
+      }
+    }
+  })
+
+  return areaKeys
+}
+
+// Init object on load
+const osmAreaKeys = getAreaTags()
+
+/**
+ * Identifies if a set of tags suggests an area feature and returns associated
+ * tags.
+ */
+export function osmTagSuggestingArea (tags) {
+  if (tags.area === 'yes') return { area: 'yes' }
+  if (tags.area === 'no') return null
+
+  // `highway` and `railway` are typically linear features, but there
+  // are a few exceptions that should be treated as areas, even in the
+  // absence of a proper `area=yes` or `areaKeys` tag.. see #4194
+  var lineKeys = {
+    highway: {
+      rest_area: true,
+      services: true
+    },
+    railway: {
+      roundhouse: true,
+      station: true,
+      traverser: true,
+      turntable: true,
+      wash: true
+    }
+  }
+  var returnTags = {}
+  for (var key in tags) {
+    if (key in osmAreaKeys && !(tags[key] in osmAreaKeys[key])) {
+      returnTags[key] = tags[key]
+      return returnTags
+    }
+    if (key in lineKeys && tags[key] in lineKeys[key]) {
+      returnTags[key] = tags[key]
+      return returnTags
+    }
+  }
+  return null
+}