fix(service): Handle responses with no headers (#438)

* Handle responses with no headers

* Address PR suggestions

* Update changelog

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## wdio-intercept-service changelog
 
 ### [ [>](https://github.com/webdriverio-community/wdio-intercept-service/tree/v.next) ] v.next / <DATE>
-
+- Handle responses with no headers (thanks @dragosMC91)
 
 ### [ [>](https://github.com/webdriverio-community/wdio-intercept-service/tree/v4.3.0) ] 4.3.0 / 17.10.2022
 - Fix header-parsing code to be RFC-compliant (thanks @jbebe)

index.js

@@ -328,6 +328,11 @@ class WebdriverAjax {
           body: parseBody(req.body),
           statusCode: req.statusCode,
         };
+        if (!req.headers) {
+          console.warn(
+            `${transformed.method} request to ${req.url} (HTTP ${req.statusCode}) had no response headers!`
+          );
+        }
       }
       return transformed;
     }
@@ -344,6 +349,9 @@ class WebdriverAjax {
     // (best effort compliance with RFC)
     function parseResponseHeaders(rawHeader) {
       const headers = {};
+      if (!rawHeader) {
+        return headers;
+      }
       const lines = rawHeader.trim().split(/(?:\r?\n)+/);
       for (const line of lines) {
         const parts = line.split(/(?<=^[^:]*):/);

test/spec/plugin_test.js

@@ -347,6 +347,27 @@ describe('webdriverajax', function testSuite() {
       });
     }
 
+    it('can parse responses with empty headers', async function () {
+      // test is disabled on firefox since the mock service only works on chrome
+      if (browser.capabilities.browserName === 'firefox') {
+        this.skip();
+      }
+      await browser.url('/post.html');
+      const mock = await browser.mock('**' + '/post*');
+      mock.respond(
+        {},
+        {
+          fetchResponse: false,
+          headers: () => ({}),
+        }
+      );
+      await browser.setupInterceptor();
+      await $('#buttonform').click();
+      mock.restore();
+      const requests = await browser.getRequests();
+      assert.deepEqual(requests[0].response.headers, {});
+    });
+
     it('can get initialised inside an iframe', async function () {
       await browser.url('/frame.html');
       await browser.setupInterceptor();