export DefaultSpatialReference definition (#2410)

* export DefaultSpatialReference definition

* spec

* fix

* fix spec

Author: deyihu

src/index.ts

@@ -35,7 +35,7 @@ Map.VERSION = version;
 export { Map };
 
 export { MapTool, DrawTool, AreaTool, DistanceTool } from './map/tool/index';
-export { default as SpatialReference } from './map/spatial-reference/SpatialReference';
+export { default as SpatialReference, getDefaultSpatialReference } from './map/spatial-reference/SpatialReference';
 // import './map/spatial-reference/SpatialReference.Arc';
 // import './map/spatial-reference/SpatialReference.WMTS';
 

src/map/spatial-reference/SpatialReference.ts

@@ -441,3 +441,8 @@ export default class SpatialReference {
         return this._pyramid;
     }
 }
+
+
+export function getDefaultSpatialReference(): Record<string, SpatialReferenceType> {
+    return JSON.parse(JSON.stringify(DefaultSpatialReference));
+}

test/map/spatial-reference/SpatialRefDefaultSpec.js

@@ -0,0 +1,22 @@
+describe('SpatialReference.Default', function () {
+
+    it('get default SpatialReference', function (done) {
+        const sps = maptalks.getDefaultSpatialReference();
+        const epsgs = ['EPSG:3857', 'EPSG:4326', 'BAIDU', 'IDENTITY', 'PRESET-VT-3857', 'PRESET-VT-4326', 'EPSG:4490', 'PRESET-3857-512', 'PRESET-4326-512', 'PRESET-4490-512'];
+        epsgs.forEach(key => {
+            expect(sps).to.have.property(key);
+            const value = sps[key];
+            expect(value).to.have.property('fullExtent');
+            expect(value).to.have.property('projection');
+            expect(value).to.have.property('resolutions');
+
+            expect(value.projection).to.be.a('string');
+            expect(value.resolutions).to.be.a('array');
+            expect(value.fullExtent).to.be.a('object');
+ 
+        });
+        done();
+
+    });
+
+});