Add core to inject k6 object into window

common/browser_context.go

@@ -66,9 +66,13 @@ func NewBrowserContext(
 	}
 
 	rt := b.vu.Runtime()
+	k6Obj := rt.ToValue(js.K6ObjectScript)
 	wv := rt.ToValue(js.WebVitalIIFEScript)
 	wvi := rt.ToValue(js.WebVitalInitScript)
 
+	if err := b.AddInitScript(k6Obj, nil); err != nil {
+		return nil, fmt.Errorf("adding k6 object to new browser context: %w", err)
+	}
 	if err := b.AddInitScript(wv, nil); err != nil {
 		return nil, fmt.Errorf("adding web vital script to new browser context: %w", err)
 	}

common/browser_context_test.go

@@ -27,18 +27,22 @@ func TestNewBrowserContext(t *testing.T) {
 
 		webVitalIIFEScriptFound := false
 		webVitalInitScriptFound := false
+		k6ObjScriptFound := false
 		for _, script := range bc.evaluateOnNewDocumentSources {
 			switch script {
 			case js.WebVitalIIFEScript:
 				webVitalIIFEScriptFound = true
 			case js.WebVitalInitScript:
 				webVitalInitScriptFound = true
+			case js.K6ObjectScript:
+				k6ObjScriptFound = true
 			default:
-				assert.Fail(t, "script is neither WebVitalIIFEScript nor WebVitalInitScript")
+				assert.Fail(t, "script is neither WebVitalIIFEScript, WebVitalInitScript, nor k6ObjScript")
 			}
 		}
 
 		assert.True(t, webVitalIIFEScriptFound, "WebVitalIIFEScript was not initialized in the context")
 		assert.True(t, webVitalInitScriptFound, "WebVitalInitScript was not initialized in the context")
+		assert.True(t, k6ObjScriptFound, "k6ObjScript was not initialized in the context")
 	})
 }

common/js/web_vital.go → common/js/embedded_scripts.go

@@ -17,3 +17,10 @@ var WebVitalIIFEScript string
 //
 //go:embed web_vital_init.js
 var WebVitalInitScript string
+
+// K6ObjectScript is used to propagate
+// information to other libraries about
+// the current user session.
+//
+//go:embed k6_object.js
+var K6ObjectScript string

common/js/k6_object.js

@@ -0,0 +1 @@
+window.k6 = {};

tests/browser_context_test.go

@@ -432,3 +432,18 @@ func TestBrowserContextCookies(t *testing.T) {
 		})
 	}
 }
+
+func TestK6Object(t *testing.T) {
+	b := newTestBrowser(t, withFileServer())
+	p := b.NewPage(nil)
+
+	url := b.staticURL("empty.html")
+	r, err := p.Goto(url, nil)
+	require.NoError(t, err)
+	require.NotNil(t, r)
+
+	k6Obj := p.Evaluate(b.toGojaValue(`() => window.k6`))
+	k6ObjGoja := b.toGojaValue(k6Obj)
+
+	assert.False(t, k6ObjGoja.Equals(goja.Null()))
+}