make SignalCancelError wrap context.Canceled

.gitignore

@@ -1,6 +1,8 @@
 .vscode
 
+*.out
+
+coverage
 playground
 
-*.out
 

Taskfile.yml

@@ -0,0 +1,23 @@
+version: "3"
+
+tasks:
+  coverage:
+    cmds:
+      - rm -rf ./coverage && mkdir ./coverage
+      - go test -v -p 1 -count 1 -race -test.gocoverdir=./coverage -cover  ./...
+      - go tool covdata percent -i=./coverage
+      - go tool covdata textfmt -i ./coverage -o ./coverage/results.out
+      - '{{if eq .CLI_ARGS "html"}} go tool cover -html ./coverage/results.out{{end}}'
+
+  lint:
+    cmds:
+      - golangci-lint run ./...
+
+
+  # Ironically the task runner is itself a dev dependency of the project.
+  # To install it run the following command:
+  #
+  # go install github.com/go-task/task/v3/cmd/task@latest
+  install-dev-deps:
+    cmds:
+      - go install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.54.2

signal.go

@@ -53,6 +53,10 @@ func (err SignalCancelError) Error() string {
 	return fmt.Sprintf("%v: received signal: %s", context.Canceled, err.Signal)
 }
 
+func (SignalCancelError) Unwrap() error {
+	return context.Canceled
+}
+
 func SignalCause(ctx context.Context) os.Signal {
 	if sigErr := (SignalCancelError{}); errors.As(context.Cause(ctx), &sigErr) {
 		return sigErr.Signal

signal_test.go

@@ -22,7 +22,16 @@ func TestWithCancelation(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, file.Close())
 
-	isCoverage := slices.ContainsFunc(os.Args, func(arg string) bool { return strings.HasPrefix(arg, "-test.gocoverdir=") })
+	coverDir := func() string {
+		args := append([]string{}, os.Args...)
+		slices.Reverse(args)
+		for _, arg := range args {
+			if dir, ok := strings.CutPrefix(arg, "-test.gocoverdir="); ok {
+				return dir
+			}
+		}
+		return ""
+	}()
 
 	build := func() *exec.Cmd {
 		args := []string{
@@ -31,8 +40,8 @@ func TestWithCancelation(t *testing.T) {
 			"-o", file.Name(),
 		}
 
-		if isCoverage {
-			args = append(args, "-coverpkg=./...")
+		if coverDir != "" {
+			args = append(args, "-cover", "-coverpkg=./...")
 		}
 
 		args = append(args, "./acceptance")
@@ -44,7 +53,8 @@ func TestWithCancelation(t *testing.T) {
 
 	acceptanceCMD := func() (cmd *exec.Cmd, stdout *bytes.Buffer) {
 		cmd = exec.Command(file.Name())
-		cmd.Env = append(cmd.Env, os.Environ()...)
+		// cmd.Env = append(cmd.Env, os.Environ()...)
+		cmd.Env = append(cmd.Env, "GOCOVERDIR="+coverDir)
 
 		stdout = new(bytes.Buffer)
 		cmd.Stdout = stdout
@@ -123,6 +133,11 @@ func TestSignalCause(t *testing.T) {
 	}
 }
 
+func TestSignalErrorIsCanceled(t *testing.T) {
+	var e error = xcontext.SignalCancelError{Signal: syscall.SIGTERM}
+	require.True(t, errors.Is(e, context.Canceled))
+}
+
 func CommandStandardIO(name string, args ...string) *exec.Cmd {
 	cmd := exec.Command(name, args...)
 	cmd.Stdout = os.Stdout