all: panic when cgo is disabled (for darwin and linux)

Fixes #11

.github/workflows/clipboard.yml

@@ -51,8 +51,20 @@ jobs:
 
     - name: Build
       run: |
-        go build
+        go build -o gclip cmd/gclip/main.go
+        go build -o gclip-gui cmd/gclip-gui/main.go
 
-    - name: Run Tests
+    - name: Run Tests with CGO_ENABLED=1
+      if: ${{ runner.os == 'Linux' || runner.os == 'macOS'}}
       run: |
-        go test -v -covermode=atomic ./...
+        CGO_ENABLED=1 go test -v -covermode=atomic .
+
+    - name: Run Tests with CGO_ENABLED=0
+      if: ${{ runner.os == 'Linux' || runner.os == 'macOS'}}
+      run: |
+        CGO_ENABLED=0 go test -v -covermode=atomic .
+
+    - name: Run Tests on Windows
+      if: ${{ runner.os == 'Windows'}}
+      run: |
+        go test -v -covermode=atomic .

clipboard_linux.go

@@ -41,7 +41,7 @@ import (
 
 const errmsg = `Failed to initialize the X11 display, and the clipboard package
 will not work properly. Install the following dependency may help:
- 
+
 	apt install -y libx11-dev
 
 If the clipboard package is in an environment without a frame buffer,
@@ -85,8 +85,6 @@ func readc(t string) ([]byte, error) {
 	}
 	defer C.free(unsafe.Pointer(data))
 	switch {
-	case n < 0:
-		return nil, errUnavailable
 	case n == 0:
 		return nil, nil
 	default:
@@ -153,7 +151,7 @@ func watch(ctx context.Context, t Format) <-chan []byte {
 				if b == nil {
 					continue
 				}
-				if bytes.Compare(last, b) != 0 {
+				if !bytes.Equal(last, b) {
 					recv <- b
 					last = b
 				}

clipboard_nocgo.go

@@ -0,0 +1,21 @@
+//go:build !windows && !cgo
+
+package clipboard
+
+import "context"
+
+func read(t Format) (buf []byte, err error) {
+	panic("clipboard: cannot use when CGO_ENABLED=0")
+}
+
+func readc(t string) ([]byte, error) {
+	panic("clipboard: cannot use when CGO_ENABLED=0")
+}
+
+func write(t Format, buf []byte) (<-chan struct{}, error) {
+	panic("clipboard: cannot use when CGO_ENABLED=0")
+}
+
+func watch(ctx context.Context, t Format) <-chan []byte {
+	panic("clipboard: cannot use when CGO_ENABLED=0")
+}

clipboard_test.go

@@ -12,6 +12,7 @@ import (
 	"image/png"
 	"os"
 	"reflect"
+	"runtime"
 	"testing"
 	"time"
 
@@ -23,6 +24,12 @@ func init() {
 }
 
 func TestClipboard(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "0" {
+			t.Skip("CGO_ENABLED is set to 0")
+		}
+	}
+
 	t.Run("image", func(t *testing.T) {
 		data, err := os.ReadFile("tests/testdata/clipboard.png")
 		if err != nil {
@@ -92,6 +99,12 @@ func TestClipboard(t *testing.T) {
 }
 
 func TestClipboardMultipleWrites(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "0" {
+			t.Skip("CGO_ENABLED is set to 0")
+		}
+	}
+
 	data, err := os.ReadFile("tests/testdata/clipboard.png")
 	if err != nil {
 		t.Fatalf("failed to read gold file: %v", err)
@@ -133,6 +146,12 @@ func TestClipboardMultipleWrites(t *testing.T) {
 }
 
 func TestClipboardConcurrentRead(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "0" {
+			t.Skip("CGO_ENABLED is set to 0")
+		}
+	}
+
 	// This test check that concurrent read/write to the clipboard does
 	// not cause crashes on some specific platform, such as macOS.
 	done := make(chan bool, 2)
@@ -153,6 +172,12 @@ func TestClipboardConcurrentRead(t *testing.T) {
 }
 
 func TestClipboardWriteEmpty(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "0" {
+			t.Skip("CGO_ENABLED is set to 0")
+		}
+	}
+
 	chg1 := clipboard.Write(clipboard.FmtText, nil)
 	if got := clipboard.Read(clipboard.FmtText); got != nil {
 		t.Fatalf("write nil to clipboard should read nil, got: %v", string(got))
@@ -166,6 +191,12 @@ func TestClipboardWriteEmpty(t *testing.T) {
 }
 
 func TestClipboardWatch(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "0" {
+			t.Skip("CGO_ENABLED is set to 0")
+		}
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*2)
 	defer cancel()
 
@@ -202,7 +233,7 @@ func TestClipboardWatch(t *testing.T) {
 				}
 				return
 			}
-			if bytes.Compare(data, want) != 0 {
+			if !bytes.Equal(data, want) {
 				t.Fatalf("received data from watch mismatch, want: %v, got %v", string(want), string(data))
 			}
 			lastRead = data
@@ -211,7 +242,6 @@ func TestClipboardWatch(t *testing.T) {
 }
 
 func BenchmarkClipboard(b *testing.B) {
-
 	b.Run("text", func(b *testing.B) {
 		data := []byte("golang.design/x/clipboard")
 
@@ -223,3 +253,45 @@ func BenchmarkClipboard(b *testing.B) {
 		}
 	})
 }
+
+func TestClipboardNoCgo(t *testing.T) {
+	if val, ok := os.LookupEnv("CGO_ENABLED"); ok && val == "1" {
+		t.Skip("CGO_ENABLED is set to 1")
+	}
+	if runtime.GOOS == "windows" {
+		t.Skip("Windows should always be tested")
+	}
+
+	t.Run("Read", func(t *testing.T) {
+		defer func() {
+			if r := recover(); r != nil {
+				return
+			}
+			t.Fatalf("expect to fail when CGO_ENABLED=0")
+		}()
+
+		clipboard.Read(clipboard.FmtText)
+	})
+
+	t.Run("Write", func(t *testing.T) {
+		defer func() {
+			if r := recover(); r != nil {
+				return
+			}
+			t.Fatalf("expect to fail when CGO_ENABLED=0")
+		}()
+
+		clipboard.Write(clipboard.FmtText, []byte("dummy"))
+	})
+
+	t.Run("Watch", func(t *testing.T) {
+		defer func() {
+			if r := recover(); r != nil {
+				return
+			}
+			t.Fatalf("expect to fail when CGO_ENABLED=0")
+		}()
+
+		clipboard.Watch(context.TODO(), clipboard.FmtText)
+	})
+}

example_test.go

@@ -4,6 +4,8 @@
 //
 // Written by Changkun Ou <changkun.de>
 
+//go:build cgo
+
 package clipboard_test
 
 import (
@@ -20,7 +22,7 @@ func ExampleWrite() {
 }
 
 func ExampleRead() {
-	fmt.Printf(string(clipboard.Read(clipboard.FmtText)))
+	fmt.Println(string(clipboard.Read(clipboard.FmtText)))
 	// Output:
 	// Hello, 世界
 }
@@ -33,7 +35,7 @@ func ExampleWatch() {
 	go func(ctx context.Context) {
 		clipboard.Write(clipboard.FmtText, []byte("你好，world"))
 	}(ctx)
-	fmt.Printf(string(<-changed))
+	fmt.Println(string(<-changed))
 	// Output:
 	// 你好，world
 }