📦 Added support for FeatureCollections

* Added support for converting FeatureCollections to GEOMETRYCOLLECTIONS
* Added protection for converting GeoJSON features
* Added option to parse WKT as Features and embed properties

.eslintrc.json

@@ -195,7 +195,7 @@
     "object-curly-newline": "off",
     "object-curly-spacing": "error",
     "object-property-newline": "error",
-    "object-shorthand": "off",
+    "object-shorthand": "error",
     "one-var": "off",
     "one-var-declaration-per-line": "error",
     "operator-assignment": ["error", "always"],

README.md

@@ -6,8 +6,10 @@
 
 - [WktParserHelper](#WktParserHelper)
   - [new WktParserHelper()](#new_WktParserHelper_new)
-  - [.convertPolygonToWK(GeoJSON, [type])](#WktParserHelper.convertPolygonToWK) ⇒ <code>string</code> \| <code>Buffer</code>
-  - [.parseFromWK(item)](#WktParserHelper.parseFromWK) ⇒ <code>object</code>
+  - ~~[.convertPolygonToWK()](#WktParserHelper.convertPolygonToWK)~~
+  - [.convertToWK(GeoJSON, [type])](#WktParserHelper.convertToWK) ⇒ <code>string</code> \| <code>Buffer</code>
+  - [.parseFromWK(item, [asFeature], [properties])](#WktParserHelper.parseFromWK) ⇒ <code>object</code>
+  - [.convertFeatureCollection(GeoJSON)](#WktParserHelper.convertFeatureCollection) ⇒ <code>string</code>
 
 <a name="new_WktParserHelper_new"></a>
 
@@ -17,27 +19,51 @@ WktParserHelper class
 
 <a name="WktParserHelper.convertPolygonToWK"></a>
 
-### WktParserHelper.convertPolygonToWK(GeoJSON, [type]) ⇒ <code>string</code> \| <code>Buffer</code>
+### ~~WktParserHelper.convertPolygonToWK()~~
+
+**_Deprecated_**
 
 Converts GeoJSON to Wkt or Wkb
 
 **Kind**: static method of [<code>WktParserHelper</code>](#WktParserHelper)  
-**Returns**: <code>string</code> \| <code>Buffer</code> - WKT or WKT
+<a name="WktParserHelper.convertToWK"></a>
+
+### WktParserHelper.convertToWK(GeoJSON, [type]) ⇒ <code>string</code> \| <code>Buffer</code>
+
+Converts GeoJSON to WKT or WKB
+
+**Kind**: static method of [<code>WktParserHelper</code>](#WktParserHelper)  
+**Returns**: <code>string</code> \| <code>Buffer</code> - WKT or WKB
 
 | Param   | Type                                                         | Default                      | Description                      |
 | ------- | ------------------------------------------------------------ | ---------------------------- | -------------------------------- |
-| GeoJSON | <code>object</code>                                          |                              | GeoJSON to convert to WKT or WKB |
+| GeoJSON | <code>Object</code>                                          |                              | GeoJSON to convert to WKT or WKB |
 | [type]  | <code>&#x27;wkt&#x27;</code> \| <code>&#x27;wkb&#x27;</code> | <code>&#x27;wkt&#x27;</code> |                                  |
 
 <a name="WktParserHelper.parseFromWK"></a>
 
-### WktParserHelper.parseFromWK(item) ⇒ <code>object</code>
+### WktParserHelper.parseFromWK(item, [asFeature], [properties]) ⇒ <code>object</code>
 
 Parses from WKT or WKB
 
 **Kind**: static method of [<code>WktParserHelper</code>](#WktParserHelper)  
 **Returns**: <code>object</code> - GeoJSON
 
-| Param | Type                                       | Description                      |
-| ----- | ------------------------------------------ | -------------------------------- |
-| item  | <code>string</code> \| <code>Buffer</code> | WKT or WKB to convert to GeoJSON |
+| Param        | Type                                       | Default            | Description                                   |
+| ------------ | ------------------------------------------ | ------------------ | --------------------------------------------- |
+| item         | <code>string</code> \| <code>Buffer</code> |                    | WKT or WKB to convert to GeoJSON              |
+| [asFeature]  | <code>boolean</code>                       | <code>false</code> |                                               |
+| [properties] | <code>object</code>                        | <code>{}</code>    | Properties to embed resulting GeoJSON feature |
+
+<a name="WktParserHelper.convertFeatureCollection"></a>
+
+### WktParserHelper.convertFeatureCollection(GeoJSON) ⇒ <code>string</code>
+
+Converts GeoJSON FeatureCollection to WKT GEOMETRYCOLLECTION
+
+**Kind**: static method of [<code>WktParserHelper</code>](#WktParserHelper)  
+**Returns**: <code>string</code> - WKT or WKT
+
+| Param   | Type                | Description                                 |
+| ------- | ------------------- | ------------------------------------------- |
+| GeoJSON | <code>Object</code> | GeoJSON FeatureCollection to convert to WKT |

index.js

@@ -11,13 +11,25 @@ class WktParserHelper {
    * Converts GeoJSON to Wkt or Wkb
    *
    * @static
-   * @param {object} GeoJSON GeoJSON to convert to WKT or WKB
+   * @deprecated Use convertToWK instead
+   * @memberof WktParserHelper
+   */
+  static convertPolygonToWK() {
+    throw new Error('method is deprecated, use convertToWK instead');
+  }
+
+  /**
+   * Converts GeoJSON to WKT or WKB
+   *
+   * @static
+   * @param {{type: string}} GeoJSON GeoJSON to convert to WKT or WKB
    * @param {'wkt'|'wkb'} [type='wkt']
-   * @returns {string|Buffer} WKT or WKT
+   * @returns {string|Buffer} WKT or WKB
    * @memberof WktParserHelper
    */
-  static convertPolygonToWK(GeoJSON, type = 'wkt') {
-    const parsed = wkx.Geometry.parseGeoJSON(GeoJSON);
+  static convertToWK(GeoJSON, type = 'wkt') {
+    const toParse = GeoJSON.type === 'Feature' ? GeoJSON.geometry : GeoJSON;
+    const parsed = wkx.Geometry.parseGeoJSON(toParse);
     return type === 'wkt' ? parsed.toWkt() : parsed.toWkb();
   }
 
@@ -26,11 +38,37 @@ class WktParserHelper {
    *
    * @static
    * @param {string|Buffer} item WKT or WKB to convert to GeoJSON
+   * @param {boolean} [asFeature=false]
+   * @param {object} [properties={}] Properties to embed resulting GeoJSON feature
    * @returns {object} GeoJSON
    * @memberof WktParserHelper
    */
-  static parseFromWK(item) {
-    return wkx.Geometry.parse(item).toGeoJSON();
+  static parseFromWK(item, asFeature = false, properties = {}) {
+    const GeoJSON = wkx.Geometry.parse(item).toGeoJSON();
+    return asFeature
+      ? {
+          type: 'Feature',
+          geometry: GeoJSON,
+          properties,
+        }
+      : GeoJSON;
+  }
+
+  /**
+   * Converts GeoJSON FeatureCollection to WKT GEOMETRYCOLLECTION
+   *
+   * @static
+   * @param {{type: 'FeatureCollection', features: object[]}} GeoJSON GeoJSON FeatureCollection to convert to WKT
+   * @returns {string} WKT or WKT
+   * @memberof WktParserHelper
+   */
+  static convertFeatureCollection(GeoJSON) {
+    if (GeoJSON.type !== 'FeatureCollection') {
+      throw new Error('GeoJSON is not a FeatureCollection');
+    }
+    return `GEOMETRYCOLLECTION(${GeoJSON.features
+      .map((d) => WktParserHelper.convertToWK(d))
+      .join(',')})`;
   }
 }
 

index.test.js

@@ -0,0 +1,57 @@
+const WktParser = require('./index');
+
+// TEST VARIABLES
+
+const TEST_FEATURE = {
+  type: 'Feature',
+  properties: {},
+  geometry: {
+    type: 'Polygon',
+    coordinates: [
+      [
+        [-3.706512451171875, 40.420074462890625],
+        [-3.70513916015625, 40.420074462890625],
+        [-3.70513916015625, 40.42144775390625],
+        [-3.706512451171875, 40.42144775390625],
+        [-3.706512451171875, 40.420074462890625],
+      ],
+    ],
+  },
+};
+
+const TEST_FEATURE_WITH_PROPERTIES = Object.assign(TEST_FEATURE, {
+  properties: {
+    test: 'Test',
+  },
+});
+
+const TEST_FEATURE_AS_WKT =
+  'POLYGON((-3.706512451171875 40.420074462890625,-3.70513916015625 40.420074462890625,-3.70513916015625 40.42144775390625,-3.706512451171875 40.42144775390625,-3.706512451171875 40.420074462890625))';
+
+const TEST_FEATURE_COLLECTION = {
+  type: 'FeatureCollection',
+  features: [TEST_FEATURE, TEST_FEATURE],
+};
+
+const TEST_FEATURE_COLLECTION_AS_WKT =
+  'GEOMETRYCOLLECTION(POLYGON((-3.706512451171875 40.420074462890625,-3.70513916015625 40.420074462890625,-3.70513916015625 40.42144775390625,-3.706512451171875 40.42144775390625,-3.706512451171875 40.420074462890625)),POLYGON((-3.706512451171875 40.420074462890625,-3.70513916015625 40.420074462890625,-3.70513916015625 40.42144775390625,-3.706512451171875 40.42144775390625,-3.706512451171875 40.420074462890625)))';
+
+// TESTS
+
+test('Same GeoJSON should always return same WKT', () => {
+  expect(WktParser.convertToWK(TEST_FEATURE)).toBe(TEST_FEATURE_AS_WKT);
+});
+
+test('Same WKT should always return same Geometry', () => {
+  expect(WktParser.parseFromWK(TEST_FEATURE_AS_WKT)).toStrictEqual(TEST_FEATURE.geometry);
+});
+
+test('Same WKT should always return same Feature, with desired properties embedded', () => {
+  expect(WktParser.parseFromWK(TEST_FEATURE_AS_WKT, true, {
+      test: 'Test',
+    })).toStrictEqual(TEST_FEATURE_WITH_PROPERTIES);
+});
+
+test('Same GeoJSON FeatureCollection should always return same wkt GEOMETRYCOLLECTION', () => {
+  expect(WktParser.convertFeatureCollection(TEST_FEATURE_COLLECTION)).toBe(TEST_FEATURE_COLLECTION_AS_WKT);
+});

package.json

@@ -1,11 +1,12 @@
 {
   "name": "wkt-parser-helper",
-  "version": "1.0.0",
+  "version": "2.0.0",
   "keywords": [
     "wkt",
     "wkb",
     "geojson",
-    "parser"
+    "parser",
+    "FeatureCollection"
   ],
   "description": "Module to help parse GeoJSONs to WKT and back",
   "main": "index.js",
@@ -16,6 +17,11 @@
     "wkx": "^0.4.8"
   },
   "devDependencies": {
-    "eslint": "^5.4"
+    "eslint": "^5.4",
+    "jest": "^25.1.0"
+  },
+  "scripts": {
+    "test": "jest",
+    "prepublish": "jest"
   }
 }