1 files changed, 279 insertions, 0 deletions
diff --git a/internal/runtimeconfig/store_test.go b/internal/runtimeconfig/store_test.go
index 168d2cd..906d7f6 100644
--- a/internal/runtimeconfig/store_test.go
+++ b/internal/runtimeconfig/store_test.go
@@ -97,6 +97,285 @@ func TestStoreReloadLogsSummary(t *testing.T) {
 	}
 }
 
+func TestSubscribe_NilListener(t *testing.T) {
+	store := New(appconfig.App{})
+	unsub := store.Subscribe(nil)
+	// Should return a no-op unsubscribe without panicking.
+	unsub()
+}
+
+func TestSubscribe_ReceivesUpdates(t *testing.T) {
+	store := New(appconfig.App{MaxTokens: 100})
+
+	var gotOld, gotNew appconfig.App
+	callCount := 0
+	unsub := store.Subscribe(func(old, new appconfig.App) {
+		gotOld = old
+		gotNew = new
+		callCount++
+	})
+
+	store.Set(appconfig.App{MaxTokens: 200})
+	if callCount != 1 {
+		t.Fatalf("expected listener called once, got %d", callCount)
+	}
+	if gotOld.MaxTokens != 100 || gotNew.MaxTokens != 200 {
+		t.Fatalf("unexpected old/new: %d / %d", gotOld.MaxTokens, gotNew.MaxTokens)
+	}
+
+	// After unsubscribe, listener must not be called again.
+	unsub()
+	store.Set(appconfig.App{MaxTokens: 300})
+	if callCount != 1 {
+		t.Fatalf("expected listener not called after unsubscribe, got %d", callCount)
+	}
+}
+
+func TestSubscribe_MultipleListeners(t *testing.T) {
+	store := New(appconfig.App{})
+	calls := [2]int{}
+	unsub0 := store.Subscribe(func(_, _ appconfig.App) { calls[0]++ })
+	unsub1 := store.Subscribe(func(_, _ appconfig.App) { calls[1]++ })
+
+	store.Set(appconfig.App{MaxTokens: 1})
+	if calls[0] != 1 || calls[1] != 1 {
+		t.Fatalf("expected both listeners called once: %v", calls)
+	}
+
+	// Unsubscribe first listener only.
+	unsub0()
+	store.Set(appconfig.App{MaxTokens: 2})
+	if calls[0] != 1 || calls[1] != 2 {
+		t.Fatalf("expected only second listener called: %v", calls)
+	}
+	unsub1()
+}
+
+func TestSet_ReturnsChanges(t *testing.T) {
+	store := New(appconfig.App{MaxTokens: 10, Provider: "ollama"})
+	changes := store.Set(appconfig.App{MaxTokens: 20, Provider: "ollama"})
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "max_tokens" {
+			found = true
+			if ch.Old != "10" || ch.New != "20" {
+				t.Fatalf("unexpected change values: %+v", ch)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected max_tokens in changes, got %+v", changes)
+	}
+}
+
+func TestSet_NoChanges(t *testing.T) {
+	cfg := appconfig.App{MaxTokens: 10}
+	store := New(cfg)
+	changes := store.Set(cfg)
+	if len(changes) != 0 {
+		t.Fatalf("expected no changes, got %+v", changes)
+	}
+}
+
+func TestReload_NilLogger(t *testing.T) {
+	// Reload with nil logger should not panic; it exercises the nil-logger guard
+	// in Reload (skipping logger.Print). LoadWithOptions returns defaults when
+	// logger is nil, so the store gets default config applied.
+	store := New(appconfig.App{MaxTokens: 1})
+	changes, err := store.Reload(nil, appconfig.LoadOptions{IgnoreEnv: true})
+	if err != nil {
+		t.Fatalf("reload failed: %v", err)
+	}
+	// Config was updated from our custom value (1) to defaults (4000).
+	if snap := store.Snapshot(); snap.MaxTokens != 4000 {
+		t.Fatalf("expected default 4000, got %d", snap.MaxTokens)
+	}
+	// Should report a change for max_tokens at minimum.
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "max_tokens" {
+			found = true
+		}
+	}
+	if !found {
+		t.Fatalf("expected max_tokens change, got %+v", changes)
+	}
+}
+
+func TestFormatSummary_NoChanges(t *testing.T) {
+	result := FormatSummary("Test", nil)
+	if result != "Test (no changes detected)." {
+		t.Fatalf("unexpected: %q", result)
+	}
+}
+
+func TestFormatSummary_WithChanges(t *testing.T) {
+	changes := []Change{
+		{Key: "a", Old: "1", New: "2"},
+		{Key: "b", Old: "x", New: "y"},
+	}
+	result := FormatSummary("Reloaded", changes)
+	if !strings.Contains(result, "Reloaded (2 changes):") {
+		t.Fatalf("missing header: %q", result)
+	}
+	if !strings.Contains(result, "- a: 1 → 2") || !strings.Contains(result, "- b: x → y") {
+		t.Fatalf("missing details: %q", result)
+	}
+}
+
+func TestStringifyValue_BoolAndFloat(t *testing.T) {
+	// Exercise the bool and float branches via Diff on App fields.
+	temp1 := 0.5
+	temp2 := 0.9
+	oldCfg := appconfig.App{CodingTemperature: &temp1}
+	newCfg := appconfig.App{CodingTemperature: &temp2}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "coding_temperature" {
+			found = true
+			if ch.Old != "0.5" || ch.New != "0.9" {
+				t.Fatalf("unexpected values: %+v", ch)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected coding_temperature change, got %+v", changes)
+	}
+}
+
+func TestStringifyValue_NilPointer(t *testing.T) {
+	// nil *float64 should produce "(unset)".
+	oldCfg := appconfig.App{}
+	temp := 0.3
+	newCfg := appconfig.App{CodingTemperature: &temp}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "coding_temperature" {
+			found = true
+			if ch.Old != "(unset)" {
+				t.Fatalf("expected (unset) for nil ptr, got %q", ch.Old)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected coding_temperature change")
+	}
+}
+
+func TestStringifyValue_NilBoolPointer(t *testing.T) {
+	// CompletionWaitAll is *bool; nil should produce "(unset)".
+	b := true
+	oldCfg := appconfig.App{}
+	newCfg := appconfig.App{CompletionWaitAll: &b}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "completion_wait_all" {
+			found = true
+			if ch.Old != "(unset)" || ch.New != "true" {
+				t.Fatalf("unexpected: old=%q new=%q", ch.Old, ch.New)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected completion_wait_all change")
+	}
+}
+
+func TestStringifyValue_StringSlice(t *testing.T) {
+	// TriggerCharacters is []string; exercise the string-slice branch.
+	oldCfg := appconfig.App{TriggerCharacters: []string{".", ":"}}
+	newCfg := appconfig.App{TriggerCharacters: []string{".", ":", "("}}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "trigger_characters" {
+			found = true
+			if ch.Old != ".,::" || ch.New != ".,:,(" {
+				// Join uses comma separator.
+				if ch.Old != ".,:" || ch.New != ".,:,(" {
+					t.Fatalf("unexpected: old=%q new=%q", ch.Old, ch.New)
+				}
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected trigger_characters change, got %+v", changes)
+	}
+}
+
+func TestStringifyValue_NilSlice(t *testing.T) {
+	// nil slice vs non-nil slice.
+	oldCfg := appconfig.App{}
+	newCfg := appconfig.App{TriggerCharacters: []string{"x"}}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "trigger_characters" {
+			found = true
+			if ch.Old != "" {
+				t.Fatalf("expected empty for nil slice, got %q", ch.Old)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected trigger_characters change")
+	}
+}
+
+func TestStringifyValue_SurfaceConfigWithTemperature(t *testing.T) {
+	// Exercise the SurfaceConfig temperature branch.
+	temp := 0.750
+	oldCfg := appconfig.App{
+		CompletionConfigs: []appconfig.SurfaceConfig{
+			{Provider: "openai", Model: "gpt-4o", Temperature: &temp},
+		},
+	}
+	newCfg := appconfig.App{
+		CompletionConfigs: []appconfig.SurfaceConfig{
+			{Provider: "openai", Model: "gpt-4o"},
+		},
+	}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "completion_configs" {
+			found = true
+			if !strings.Contains(ch.Old, "@0.750") {
+				t.Fatalf("expected temperature in old value, got %q", ch.Old)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected completion_configs change")
+	}
+}
+
+func TestStringifyValue_SurfaceConfigEmptyProvider(t *testing.T) {
+	// Exercise the SurfaceConfig branch where provider is empty.
+	oldCfg := appconfig.App{
+		ChatConfigs: []appconfig.SurfaceConfig{
+			{Provider: "", Model: "some-model"},
+		},
+	}
+	newCfg := appconfig.App{}
+	changes := Diff(oldCfg, newCfg)
+	found := false
+	for _, ch := range changes {
+		if ch.Key == "chat_configs" {
+			found = true
+			if ch.Old != "some-model" {
+				t.Fatalf("expected 'some-model', got %q", ch.Old)
+			}
+		}
+	}
+	if !found {
+		t.Fatalf("expected chat_configs change")
+	}
+}
+
 func TestDiff_SurfaceModel(t *testing.T) {
 	oldCfg := appconfig.App{CompletionConfigs: []appconfig.SurfaceConfig{{Provider: "openai", Model: "gpt-4o"}}}
 	newCfg := appconfig.App{CompletionConfigs: []appconfig.SurfaceConfig{{Provider: "anthropic", Model: "claude-3-5-sonnet"}}}