fix(context): return values for isPrerender and isClient (#1537)

* fix(context): return values for isPrerender and isClient

* Update context.ts

* Update context.spec.tsx

Author: simonhaenisch

src/runtime/context.ts

@@ -9,8 +9,10 @@ export const getContext = (_elm: HTMLElement, context: string) => {
     return win;
   } else if (context === 'document') {
     return doc;
-  } else if (context === 'isServer') {
+  } else if (context === 'isServer' || context === 'isPrerender') {
     return BUILD.hydrateServerSide;
+  } else if (context === 'isClient') {
+    return !BUILD.hydrateServerSide;
   } else if (context === 'resourcesUrl' || context === 'publicPath') {
     return getAssetPath('.');
   } else if (context === 'queue') {

src/runtime/test/context.spec.tsx

@@ -13,6 +13,8 @@ describe('context', () => {
       @Prop({ context: 'window' }) win: Window;
       @Prop({ context: 'document' }) doc: Document;
       @Prop({ context: 'isServer' }) isServer: boolean;
+      @Prop({ context: 'isPrerender' }) isPrerender: boolean;
+      @Prop({ context: 'isClient' }) isClient: boolean;
       @Prop({ context: 'resourcesUrl' }) resourcesUrl: string;
       @Prop({ context: 'publicPath' }) publicPath: string;
       @Prop({ context: 'queue' }) queue: QueueApi;
@@ -24,6 +26,9 @@ describe('context', () => {
 
     expect(rootInstance.win).toEqual(win);
     expect(rootInstance.doc).toEqual(doc);
+    expect(rootInstance.isServer).toEqual(false);
+    expect(rootInstance.isPrerender).toEqual(false);
+    expect(rootInstance.isClient).toEqual(true);
     expect(rootInstance.resourcesUrl).toEqual('/');
     expect(rootInstance.publicPath).toEqual('/');
     expect(rootInstance.queue.write).toEqual(writeTask);