1 files changed, 87 insertions, 0 deletions
diff --git a/internal/hexaiaction/action_handler_test.go b/internal/hexaiaction/action_handler_test.go
new file mode 100644
index 0000000..1d811fe
--- /dev/null
+++ b/internal/hexaiaction/action_handler_test.go
@@ -0,0 +1,87 @@
+package hexaiaction
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"codeberg.org/snonux/hexai/internal/appconfig"
+)
+
+func TestActionHandlers_AreSelfRegistered(t *testing.T) {
+	handlers := codeActionHandlers()
+	for _, kind := range []ActionKind{
+		ActionSkip,
+		ActionRewrite,
+		ActionDiagnostics,
+		ActionDocument,
+		ActionGoTest,
+		ActionSimplify,
+		ActionFixTypos,
+		ActionCustom,
+		ActionCustomPrompt,
+	} {
+		if _, ok := handlers[kind]; !ok {
+			t.Fatalf("expected handler for %q", kind)
+		}
+	}
+}
+
+func TestActionHandlers_SnapshotDoesNotMutateRegistry(t *testing.T) {
+	handlers := codeActionHandlers()
+	delete(handlers, ActionSkip)
+	if _, ok := lookupActionHandler(ActionSkip); !ok {
+		t.Fatal("mutating handler snapshot changed registry")
+	}
+}
+
+func TestExecuteAction_UnknownFallsBackToSelection(t *testing.T) {
+	cfg := appconfig.App{}
+	parts := InputParts{Selection: "original"}
+	out, err := executeAction(context.Background(), ActionKind("missing"), parts, &cfg, fakeDoer{"ignored"}, nil, nil)
+	if err != nil {
+		t.Fatalf("executeAction: %v", err)
+	}
+	if out != "original" {
+		t.Fatalf("expected fallback selection, got %q", out)
+	}
+}
+
+func TestActionHandlerRegistryRejectsInvalidRegistrations(t *testing.T) {
+	tests := map[string]func(*actionHandlerRegistry){
+		"empty kind": func(registry *actionHandlerRegistry) {
+			registry.register("", actionHandlerFunc(handleSkipAction))
+		},
+		"nil handler": func(registry *actionHandlerRegistry) {
+			registry.register(ActionKind("nil"), nil)
+		},
+		"duplicate kind": func(registry *actionHandlerRegistry) {
+			registry.register(ActionKind("dup"), actionHandlerFunc(handleSkipAction))
+			registry.register(ActionKind("dup"), actionHandlerFunc(handleSkipAction))
+		},
+	}
+
+	for name, run := range tests {
+		t.Run(name, func(t *testing.T) {
+			defer func() {
+				if recovered := recover(); recovered == nil {
+					t.Fatal("expected panic")
+				}
+			}()
+			run(newActionHandlerRegistry())
+		})
+	}
+}
+
+func TestActionHandlerRegistryNilPanicNamesKind(t *testing.T) {
+	defer func() {
+		recovered := recover()
+		if recovered == nil {
+			t.Fatal("expected panic")
+		}
+		if !strings.Contains(recovered.(string), "custom") {
+			t.Fatalf("expected panic to name kind, got %v", recovered)
+		}
+	}()
+	newActionHandlerRegistry().register(ActionCustom, nil)
+}