Add split-by-example support for Playwright

internal/command/request_param.go

@@ -26,8 +26,8 @@ func createRequestParam(ctx context.Context, cfg *config.Config, files []string,
 		})
 	}
 
-	// Splitting files by example is only supported for rspec, cucumber, and pytest runners
-	if runner.Name() != "RSpec" && runner.Name() != "Cucumber" && runner.Name() != "pytest" {
+	// Splitting files by example is only supported for rspec, cucumber, pytest, and playwright runners
+	if runner.Name() != "RSpec" && runner.Name() != "Cucumber" && runner.Name() != "pytest" && runner.Name() != "Playwright" {
 		params := api.TestPlanParams{
 			Identifier:     cfg.Identifier,
 			Parallelism:    cfg.Parallelism,

internal/command/run_test.go

@@ -753,7 +753,7 @@ func TestCreateRequestParams_NonRSpec(t *testing.T) {
 	defer svr.Close()
 
 	runners := []TestRunner{
-		runner.Jest{}, runner.Playwright{}, runner.Cypress{},
+		runner.Jest{}, runner.Cypress{},
 	}
 
 	for _, r := range runners {

internal/runner/playwright.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"slices"
+	"strings"
 
 	"github.com/buildkite/test-engine-client/internal/debug"
 	"github.com/buildkite/test-engine-client/internal/plan"
@@ -162,8 +163,77 @@ func (p Playwright) GetFiles() ([]string, error) {
 	return files, nil
 }
 
+// GetExamples returns an array of test examples within the given files.
 func (p Playwright) GetExamples(files []string) ([]plan.TestCase, error) {
-	return nil, fmt.Errorf("not supported in Playwright")
+	if len(files) == 0 {
+		return []plan.TestCase{}, nil
+	}
+
+	cmdName, cmdArgs, err := p.commandNameAndArgs(p.TestCommand, files)
+	if err != nil {
+		return []plan.TestCase{}, err
+	}
+
+	cmdArgs = append(cmdArgs, "--list", "--reporter=json")
+
+	debug.Printf("Running `%s %s` to list tests", cmdName, strings.Join(cmdArgs, " "))
+
+	// We use Output() instead of CombinedOutput() because the JSON reporter
+	// outputs to stdout, and mixing stderr would corrupt the JSON.
+	output, err := exec.Command(cmdName, cmdArgs...).Output()
+	if err != nil {
+		// Include stderr in error message for debugging
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			return []plan.TestCase{}, fmt.Errorf("failed to list playwright tests: %s", exitErr.Stderr)
+		}
+		return []plan.TestCase{}, fmt.Errorf("failed to list playwright tests: %w", err)
+	}
+
+	var report PlaywrightReport
+	if err := json.Unmarshal(output, &report); err != nil {
+		return []plan.TestCase{}, fmt.Errorf("failed to parse playwright test list output: %s", err)
+	}
+
+	var testCases []plan.TestCase
+	for _, suite := range report.Suites {
+		testCases = append(testCases, p.getTestCasesFromSuite(suite, suite.Title)...)
+	}
+
+	return testCases, nil
+}
+
+// getTestCasesFromSuite recursively traverses the Playwright report suite and returns all test cases.
+// Playwright's report format is a tree structure, where each suite can contain multiple specs and sub-suites.
+func (p Playwright) getTestCasesFromSuite(suite PlaywrightReportSuite, suiteName string) []plan.TestCase {
+	var testCases []plan.TestCase
+
+	for _, spec := range suite.Specs {
+		testCases = append(testCases, mapSpecToTestCase(spec, suiteName))
+	}
+
+	for _, subSuite := range suite.Suites {
+		testCases = append(testCases, p.getTestCasesFromSuite(subSuite, fmt.Sprintf("%s %s", suiteName, subSuite.Title))...)
+	}
+
+	return testCases
+}
+
+// mapSpecToTestCase converts a Playwright spec to a plan.TestCase.
+// The scope has to match with the scope generated by Buildkite test collector.
+// In Buildkite test collector, the scope is generated using Playwright built-in reporter function, titlePath().
+// titlePath function returns an array of suite's title from the root suite down to the current test,
+// which is then joined with a space separator to form the scope.
+// For more details, see:
+// [Buildkite Test Collector - Playwright implementation](https://github.com/buildkite/test-collector-javascript/blob/42b803a618a15a07edf0169038ef4b5eba88f98d/playwright/reporter.js#L47)
+// [Playwright titlePath implementation](https://github.com/microsoft/playwright/blob/523e50088a7f982dd96aacdb260dfbd1189159b1/packages/playwright/src/common/test.ts#L126)
+// [Playwright suite structure](https://playwright.dev/docs/api/class-suite)
+func mapSpecToTestCase(spec PlaywrightSpec, suiteName string) plan.TestCase {
+	projectName := spec.Tests[0].ProjectName
+	return plan.TestCase{
+		Name:  spec.Title,
+		Path:  fmt.Sprintf("%s:%d", spec.File, spec.Line),
+		Scope: fmt.Sprintf(" %s %s %s", projectName, suiteName, spec.Title),
+	}
 }
 
 type PlaywrightTest struct {

internal/runner/playwright_test.go

@@ -266,3 +266,69 @@ func TestPlaywrightGetFiles(t *testing.T) {
 		t.Errorf("Playwright.GetFiles() diff (-got +want):\n%s", diff)
 	}
 }
+
+func TestPlaywrightGetExamples(t *testing.T) {
+	changeCwd(t, "./testdata/playwright")
+
+	playwright := NewPlaywright(RunnerConfig{
+		// Use npx directly because yarn adds prefix output to stdout that corrupts JSON parsing
+		TestCommand: "npx playwright test",
+	})
+
+	files := []string{"tests/example.spec.js"}
+	got, err := playwright.GetExamples(files)
+	if err != nil {
+		t.Fatalf("Playwright.GetExamples(%v) error = %v", files, err)
+	}
+
+	// example.spec.js has 2 tests in a "home page" describe block.
+	// With 2 projects (chromium, firefox), we expect 4 test cases.
+	want := []plan.TestCase{
+		{
+			Name:  "has title",
+			Path:  "example.spec.js:4",
+			Scope: " chromium example.spec.js home page has title",
+		},
+		{
+			Name:  "has title",
+			Path:  "example.spec.js:4",
+			Scope: " firefox example.spec.js home page has title",
+		},
+		{
+			Name:  "says hello",
+			Path:  "example.spec.js:10",
+			Scope: " chromium example.spec.js home page says hello",
+		},
+		{
+			Name:  "says hello",
+			Path:  "example.spec.js:10",
+			Scope: " firefox example.spec.js home page says hello",
+		},
+	}
+
+	// Sort both slices by scope for consistent comparison
+	sorter := cmp.Transformer("Sort", func(in []plan.TestCase) []plan.TestCase {
+		out := append([]plan.TestCase(nil), in...)
+		slices.SortFunc(out, func(a, b plan.TestCase) int {
+			return strings.Compare(a.Scope, b.Scope)
+		})
+		return out
+	})
+
+	if diff := cmp.Diff(got, want, sorter); diff != "" {
+		t.Errorf("Playwright.GetExamples(%v) diff (-got +want):\n%s", files, diff)
+	}
+}
+
+func TestPlaywrightGetExamples_EmptyFiles(t *testing.T) {
+	playwright := NewPlaywright(RunnerConfig{})
+
+	got, err := playwright.GetExamples([]string{})
+	if err != nil {
+		t.Errorf("Playwright.GetExamples([]) error = %v", err)
+	}
+
+	if len(got) != 0 {
+		t.Errorf("Playwright.GetExamples([]) = %v, want empty slice", got)
+	}
+}