test: add concurrent read test

Author: changkun

.github/workflows/clipboard.yml

@@ -33,7 +33,7 @@ jobs:
     - uses: actions/setup-go@v2
       with:
         stable: 'false'
-        go-version: '1.16.0-rc1'
+        go-version: '1.16.0'
 
     - name: TestLinux
       run: |

clipboard_test.go

@@ -99,6 +99,26 @@ func TestClipboardMultipleWrites(t *testing.T) {
 	}
 }
 
+func TestClipboardConcurrentRead(t *testing.T) {
+	// 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)
+	go func() {
+		defer func() {
+			done <- true
+		}()
+		clipboard.Read(clipboard.FmtText)
+	}()
+	go func() {
+		defer func() {
+			done <- true
+		}()
+		clipboard.Read(clipboard.FmtImage)
+	}()
+	<-done
+	<-done
+}
+
 func BenchmarkClipboard(b *testing.B) {
 
 	b.Run("text", func(b *testing.B) {