Align shared debug help and completion

completion_query_test.go

@@ -120,3 +120,51 @@ func TestCompletionQueryDiscovery(t *testing.T) {
 		t.Fatalf("discovery outcome=%#v reply=%q", outcome, output.String())
 	}
 }
+
+func TestSharedDebugHelpAndCompletion(t *testing.T) {
+	var factories, setters, checks, handlers int
+	command := NewCommand(CommandSpec[struct{}]{
+		Name:       "run",
+		NewInput:   func() struct{} { factories++; return struct{}{} },
+		Flags:      []Flag[struct{}]{BoolFlag(FlagMeta{Name: "debug", Short: "d", Usage: "application tracing", Required: true, Completion: CompleteChoices(CompletionChoice{Value: "true"}, CompletionChoice{Value: "trace"})}, true, func(*struct{}, Supplied[bool]) { setters++ })},
+		CheckInput: func(struct{}) error { checks++; return nil },
+		Run:        func(Invocation, struct{}) Outcome { handlers++; return Success() },
+	})
+	app, err := New(Identity{Name: "example"}, command, Completion("example"), Alias("shortcut", "run"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, args := range [][]string{{"run", "--help"}, {"help", "run"}, {"shortcut", "--help"}, {"help", "shortcut"}, {"run", "--unknown"}, {"shortcut", "--unknown"}} {
+		var output, diagnostic bytes.Buffer
+		result := app.Execute(context.Background(), args, Streams{Out: &output, Err: &diagnostic})
+		text := output.String() + diagnostic.String()
+		if strings.Count(text, "--debug") != 1 || !strings.Contains(text, "-d") || !strings.Contains(text, "application tracing") || !strings.Contains(text, "application input defaults to true") || !strings.Contains(text, "required") || !strings.Contains(text, "default: false") {
+			t.Fatalf("%v: outcome=%#v text=%q", args, result, text)
+		}
+	}
+	for _, tc := range []struct {
+		args  []string
+		want  string
+		count int
+	}{
+		{[]string{"__complete", "run", "--deb"}, "--debug", 1},
+		{[]string{"__complete", "run", "-"}, "\n-d\t", 1},
+		{[]string{"__complete", "run", "--debug=tr"}, "trace", 1},
+		{[]string{"__complete", "run", "-d=tr"}, "trace", 1},
+	} {
+		var output bytes.Buffer
+		result := app.Execute(context.Background(), tc.args, Streams{Out: &output, Err: io.Discard})
+		if result.Kind != OutcomeSuccess || strings.Count(output.String(), tc.want) != tc.count {
+			t.Fatalf("%v: %#v %q", tc.args, result, output.String())
+		}
+	}
+	if factories != 0 || setters != 0 || checks != 0 || handlers != 0 {
+		t.Fatalf("callbacks: %d %d %d %d", factories, setters, checks, handlers)
+	}
+	if result := app.Execute(context.Background(), []string{"run", "--debug=invalid", "--help"}, Streams{Out: io.Discard, Err: io.Discard}); result.Kind != OutcomeUsage {
+		t.Fatalf("help skipped boolean validation: %#v", result)
+	}
+	if result := app.Execute(context.Background(), []string{"run", "--debug=trace"}, Streams{Out: io.Discard, Err: io.Discard}); result.Kind != OutcomeUsage {
+		t.Fatalf("suggestion bypassed boolean parsing: %#v", result)
+	}
+}