Update context waits for start

src/index.test.ts

@@ -48,7 +48,7 @@ test('Should perform an initial fetch as POST', async () => {
     };
     const client = new UnleashClient(config);
     await client.start();
-    
+
     const request = getTypeSafeRequest(fetchMock, 0);
     const body = JSON.parse(request.body as string);
 
@@ -65,7 +65,7 @@ test('Should perform an initial fetch as GET', async () => {
     };
     const client = new UnleashClient(config);
     await client.start();
-    
+
     const request = getTypeSafeRequest(fetchMock, 0);
 
     expect(request.method).toBe('GET');
@@ -852,6 +852,27 @@ test('Should update context fields on request', async () => {
     expect(url.searchParams.get('environment')).toEqual('prod');
 });
 
+test('Updating context should wait on asynchronous start', async () => {
+    fetchMock.mockResponses(
+        [JSON.stringify(data), { status: 200 }],
+        [JSON.stringify(data), { status: 200 }]
+    );
+    const config: IConfig = {
+        url: 'http://localhost/test',
+        clientKey: '12',
+        appName: 'web',
+        environment: 'prod',
+    };
+    const client = new UnleashClient(config);
+
+    client.start();
+    await client.updateContext({
+        userId: '123'
+    });
+
+    expect(fetchMock).toBeCalledTimes(2);
+});
+
 test('Should not replace sessionId when updating context', async () => {
     fetchMock.mockResponses(
         [JSON.stringify(data), { status: 200 }],

src/index.ts

@@ -210,7 +210,7 @@ export class UnleashClient extends TinyEmitter {
         const toggle = this.toggles.find((t) => t.name === toggleName);
         const enabled = toggle?.enabled || false;
         const variant = toggle ? toggle.variant : defaultVariant;
-        
+
         this.metrics.count(toggleName, true);
         if (toggle?.impressionData || this.impressionDataAll) {
             const event = this.eventsHandler.createImpressionEvent(
@@ -240,9 +240,21 @@ export class UnleashClient extends TinyEmitter {
             sessionId: this.context.sessionId,
         };
         this.context = { ...staticContext, ...context };
+
         if (this.timerRef) {
             await this.fetchToggles();
         }
+        else {
+            await new Promise<void>(resolve => {
+                const listener = () => {
+                    this.fetchToggles().then(() => {
+                        this.off(EVENTS.READY, listener);
+                        resolve();
+                    });
+                };
+                this.once(EVENTS.READY, listener);
+            });
+        }
     }
 
     public getContext() {
@@ -344,7 +356,7 @@ export class UnleashClient extends TinyEmitter {
                 const url = isPOST ? this.url : urlWithContextAsQuery(this.url, this.context);
                 const method = isPOST ? 'POST' : 'GET';
                 const body = isPOST ? JSON.stringify({context: this.context}) : undefined;
-                
+
                 const response = await this.fetch(url.toString(), {
                     method,
                     cache: 'no-cache',