Initial commit.

flock_test.go

@@ -0,0 +1,111 @@
+package flock
+
+import (
+	"errors"
+	"os"
+	"testing"
+	"time"
+)
+
+func TestLock_basic(t *testing.T) {
+	const path = "/tmp/fsutil-test-lock"
+
+	f, err := Lock(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// locked is closed once the goroutine acquires the lock.
+	locked := make(chan struct{})
+	go func() {
+		f2, err := Lock(path) // blocks until f is unlocked
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		close(locked)
+		Unlock(f2)
+	}()
+
+	// Goroutine should be blocked while we hold the lock.
+	select {
+	case <-locked:
+		t.Fatal("goroutine acquired lock while we hold it")
+	case <-time.After(50 * time.Millisecond):
+	}
+
+	Unlock(f)
+
+	// Now the goroutine should unblock and acquire the lock.
+	select {
+	case <-locked:
+	case <-time.After(time.Second):
+		t.Fatal("goroutine never acquired lock after release")
+	}
+}
+
+func TestLock_badPath(t *testing.T) {
+	_, err := Lock("./dne/file.lock")
+	if err == nil {
+		t.Fatal("expected error for bad path")
+	}
+}
+
+func TestTryLock(t *testing.T) {
+	const path = "/tmp/fsutil-test-lock"
+
+	f, err := TryLock(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer Unlock(f)
+
+	// While f holds the lock, TryLock should return ErrLocked.
+	_, err = TryLock(path)
+	if !errors.Is(err, ErrLocked) {
+		t.Fatalf("expected ErrLocked, got %v", err)
+	}
+
+	// After unlocking, TryLock should succeed.
+	if err := Unlock(f); err != nil {
+		t.Fatal(err)
+	}
+
+	f2, err := TryLock(path)
+	if err != nil {
+		t.Fatalf("expected lock after unlock, got %v", err)
+	}
+	Unlock(f2)
+}
+
+func TestTryLockFile(t *testing.T) {
+	const path = "/tmp/fsutil-test-lockfile"
+
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR, 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+
+	if err := TryLockFile(f); err != nil {
+		t.Fatal(err)
+	}
+
+	f2, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR, 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f2.Close()
+
+	if err := TryLockFile(f2); !errors.Is(err, ErrLocked) {
+		t.Fatalf("expected ErrLocked, got %v", err)
+	}
+
+	if err := Unlock(f); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := TryLockFile(f2); err != nil {
+		t.Fatalf("expected lock after unlock, got %v", err)
+	}
+}