Handle text API responses

spec/src/modules/tracker.js

@@ -8143,6 +8143,33 @@ describe('ConstructorIO - Tracker', () => {
       });
     });
 
+    it('Should receive an error message when rate limited (429)', (done) => {
+      // Create a mock response for 429 error
+      fetchSpy = sinon.spy(() => Promise.resolve({
+        ok: false,
+        status: 429,
+        statusText: 'Too Many Requests',
+        headers: new Map([['content-type', 'text/plain']]),
+        text: () => Promise.resolve('Too many requests'),
+      }));
+
+      const { tracker } = new ConstructorIO({
+        apiKey: testApiKey,
+        fetch: fetchSpy,
+      });
+
+      tracker.trackInputFocus(userParameters);
+
+      tracker.on('error', (response) => {
+        expect(response).to.have.property('url');
+        expect(response).to.have.property('method');
+        expect(response).to.have.property('message');
+        expect(response.message).to.not.be.undefined;
+        expect(response.message).to.equal('Too many requests');
+        done();
+      });
+    });
+
     it('Should receive an error message when making a request to an invalid endpoint', (done) => {
       const { tracker } = new ConstructorIO({
         apiKey: testApiKey,

src/modules/tracker.js

@@ -139,6 +139,7 @@ function send(url, userParameters, networkParameters, method = 'GET', body = {})
 
   if (request) {
     const instance = this;
+    const emitError = helpers.getEmitError(instance, { url, method });
 
     request.then((response) => {
       // Request was successful, and returned a 2XX status code
@@ -152,26 +153,25 @@ function send(url, userParameters, networkParameters, method = 'GET', body = {})
 
       // Request was successful, but returned a non-2XX status code
       else {
-        response.json().then((json) => {
-          instance.eventemitter.emit('error', {
-            url,
-            method,
-            message: json && json.message,
+        const contentType = response.headers.get('Content-Type') || '';
+
+        if (contentType.includes('application/json')) {
+          response.json().then((json) => {
+            emitError(json && json.message);
+          }).catch((error) => {
+            emitError(error.type);
           });
-        }).catch((error) => {
-          instance.eventemitter.emit('error', {
-            url,
-            method,
-            message: error.type,
+        } else {
+          // If not JSON, fallback to text
+          response.text().then((text) => {
+            emitError(text || 'Unknown error message');
+          }).catch((error) => {
+            emitError(`Error reading text: ${error.message}`);
           });
-        });
+        }
       }
     }).catch((error) => {
-      instance.eventemitter.emit('error', {
-        url,
-        method,
-        message: error.toString(),
-      });
+      emitError(error.toString());
     });
   }
 }

src/utils/helpers.js

@@ -134,6 +134,12 @@ const utils = {
 
     return url;
   },
+
+  getEmitError(instance, { url, method }) {
+    return function emitError(message) {
+      instance.eventemitter.emit('error', { url, method, message });
+    };
+  },
 };
 
 module.exports = utils;