vendor tsgo

tools/tsgo/internal/testutil/baseline/testmain.go

@@ -0,0 +1,103 @@
+package baseline
+
+import (
+	"bufio"
+	"fmt"
+	"hash/fnv"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/collections"
+)
+
+var (
+	// recordedBaselines tracks all baseline file paths that were written during the test run.
+	recordedBaselines collections.SyncSet[string]
+
+	// trackingInitialized is set to true when Track() is called.
+	trackingInitialized bool
+
+	// trackingDir is the directory where tracking files should be written.
+	// If non-empty, baseline tracking is enabled.
+	// Set by Herebyfile.mjs when running full test suites with tracking enabled.
+	trackingDir = os.Getenv("TSGO_BASELINE_TRACKING_DIR")
+)
+
+// Track sets up baseline tracking and returns a cleanup function that writes the tracking file.
+// It should be called from TestMain using defer:
+//
+//	func TestMain(m *testing.M) {
+//	    defer baseline.Track()()
+//	    m.Run()
+//	}
+func Track() func() {
+	trackingInitialized = true
+
+	if trackingDir == "" {
+		return func() {}
+	}
+
+	// Hash the entire call stack to create a unique filename per calling package.
+	// This must be done in Track(), not in the deferred cleanup, because
+	// the deferred function's call stack won't include the caller's info.
+	var pcs [32]uintptr
+	n := runtime.Callers(2, pcs[:]) // Skip Track and runtime.Callers
+	h := fnv.New64a()
+	frames := runtime.CallersFrames(pcs[:n])
+	for {
+		frame, more := frames.Next()
+		h.Write([]byte(frame.File))
+		if !more {
+			break
+		}
+	}
+	trackingPath := filepath.Join(trackingDir, fmt.Sprintf("%016x.txt", h.Sum64()))
+
+	return func() {
+		// After tests complete, write the recorded baselines
+		writeRecordedBaselines(trackingPath)
+	}
+}
+
+// recordBaseline adds a baseline file path to the recorded set.
+// The path should be relative to the baselines/reference directory.
+func recordBaseline(t testing.TB, relativePath string) {
+	if trackingDir != "" {
+		if !trackingInitialized {
+			t.Error("baseline: package uses baselines but TestMain did not call baseline.Track(). " +
+				"Please add a TestMain function with: defer baseline.Track()()")
+			return
+		}
+		recordedBaselines.Add(relativePath)
+	}
+}
+
+// writeRecordedBaselines writes the list of recorded baseline files to a tracking file.
+func writeRecordedBaselines(trackingPath string) {
+	if recordedBaselines.Size() == 0 {
+		return
+	}
+
+	if err := doWriteRecordedBaselines(trackingPath); err != nil {
+		fmt.Fprintf(os.Stderr, "baseline: failed to write tracking file %s: %v\n", trackingPath, err)
+		os.Exit(1)
+	}
+}
+
+func doWriteRecordedBaselines(trackingPath string) error {
+	f, err := os.Create(trackingPath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	w := bufio.NewWriter(f)
+	for baseline := range recordedBaselines.Keys() {
+		if _, err := fmt.Fprintln(w, baseline); err != nil {
+			return err
+		}
+	}
+	return w.Flush()
+}