Add testRunId to the k6 object

We can now add the testRunId to the k6 object which is injected into
the page, allowing external apps to work with the k6 object, while also
allowing them to link back to the test run id.

browser/mapping.go

@@ -1008,7 +1008,7 @@ func mapBrowser(vu moduleVU) mapping { //nolint:funlen
 				return nil, err //nolint:wrapcheck
 			}
 
-			if err := initBrowserContext(bctx); err != nil {
+			if err := initBrowserContext(bctx, vu.testRunID); err != nil {
 				return nil, err
 			}
 
@@ -1039,7 +1039,7 @@ func mapBrowser(vu moduleVU) mapping { //nolint:funlen
 				return nil, err //nolint:wrapcheck
 			}
 
-			if err := initBrowserContext(b.Context()); err != nil {
+			if err := initBrowserContext(b.Context(), vu.testRunID); err != nil {
 				return nil, err
 			}
 
@@ -1048,12 +1048,14 @@ func mapBrowser(vu moduleVU) mapping { //nolint:funlen
 	}
 }
 
-func initBrowserContext(bctx *common.BrowserContext) error {
+func initBrowserContext(bctx *common.BrowserContext, testRunID string) error {
 	// Setting a k6 object which will contain k6 specific metadata
 	// on the current test run. This allows external applications
 	// (such as Grafana Faro) to identify that the session is a k6
 	// automated one and not one driven by a real person.
-	if err := bctx.AddInitScript("window.k6 = {}"); err != nil {
+	if err := bctx.AddInitScript(
+		fmt.Sprintf(`window.k6 = { testRunId: %q }`, testRunID),
+	); err != nil {
 		return fmt.Errorf("adding k6 object to new browser context: %w", err)
 	}
 

tests/browser_context_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/grafana/xk6-browser/common"
+	"github.com/grafana/xk6-browser/env"
 )
 
 func TestBrowserContextAddCookies(t *testing.T) {
@@ -627,17 +628,53 @@ func TestBrowserContextClearCookies(t *testing.T) {
 func TestK6Object(t *testing.T) {
 	t.Parallel()
 
-	_, rt, _, cleanUp := startIteration(t)
-	defer cleanUp()
+	tests := []struct {
+		name      string
+		testRunID string
+		want      string
+	}{
+		{
+			name: "empty_testRunId",
+			want: `{"testRunId":""}`,
+		},
+		{
+			name:      "with_testRunId",
+			testRunID: "123456",
+			want:      `{"testRunId":"123456"}`,
+		},
+	}
 
-	got, err := rt.RunString(`
-		const p = browser.newPage()
-		p.goto("about:blank")
-		const o = p.evaluate(() => window.k6)
-		JSON.stringify(o)
-	`)
-	require.NoError(t, err)
-	assert.Equal(t, "{}", got.String())
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			_, rt, _, cleanUp := startIteration(t, env.ConstLookup(env.K6TestRunID, tt.testRunID))
+			defer cleanUp()
+
+			// First test with browser.newPage
+			got, err := rt.RunString(`
+				const p = browser.newPage()
+				p.goto("about:blank")
+				const o = p.evaluate(() => window.k6)
+				JSON.stringify(o)
+			`)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got.String())
+
+			// Now test with with browser.newContext
+			got, err = rt.RunString(`
+				browser.closeContext()
+				const c = browser.newContext()
+				const p2 = c.newPage()
+				p2.goto("about:blank")
+				const o2 = p2.evaluate(() => window.k6)
+				JSON.stringify(o2)
+			`)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, got.String())
+		})
+	}
 }
 
 func TestBrowserContextTimeout(t *testing.T) {