make keybinds configurable and consolidate

config_test.go

@@ -56,6 +56,10 @@ directory = "/tmp/gh-threads-cache"
 
 [editing]
 mode = "standard"
+
+[keybindings.navigation]
+down = ["ctrl+j"]
+up = ["ctrl+k"]
 `
 	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
 		t.Fatal(err)
@@ -76,11 +80,63 @@ mode = "standard"
 		strings.Join(got.Threads.StatusOrder, ",") != "resolved,unresolved,outdated" ||
 		got.Threads.WithinStatus != "timestamp" || got.Cache.Enabled ||
 		got.Cache.MaxAge.Duration != 48*time.Hour || got.Cache.Directory != "/tmp/gh-threads-cache" ||
-		got.Editing.Mode != "standard" {
+		got.Editing.Mode != "standard" ||
+		strings.Join(got.KeyBindings.Navigation.Down, ",") != "ctrl+j" ||
+		strings.Join(got.KeyBindings.Navigation.Up, ",") != "ctrl+k" {
 		t.Fatalf("config = %#v", got)
 	}
 }
 
+func TestValidateConfigRejectsEmptyKeyBinding(t *testing.T) {
+	config := defaultConfig()
+	config.KeyBindings.Navigation.Down = nil
+	err := validateConfig(config)
+	if err == nil || !strings.Contains(err.Error(), "keybindings.navigation.down") {
+		t.Fatalf("empty binding error = %v", err)
+	}
+}
+
+func TestValidateConfigRejectsKeyConflictsInTheSameContext(t *testing.T) {
+	tests := []struct {
+		name    string
+		change  func(*Config)
+		context string
+		actions []string
+	}{
+		{
+			name: "thread navigation and reply",
+			change: func(config *Config) {
+				config.KeyBindings.Threads.Reply = []string{"j"}
+			},
+			context: "review threads",
+			actions: []string{"down", "reply"},
+		},
+		{
+			name: "vim motion and cancel",
+			change: func(config *Config) {
+				config.KeyBindings.Input.Cancel = []string{"b"}
+			},
+			context: "Vim Normal mode",
+			actions: []string{"cancel", "word_backward"},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			config := defaultConfig()
+			test.change(&config)
+			err := validateConfig(config)
+			if err == nil || !strings.Contains(err.Error(), test.context) {
+				t.Fatalf("conflict error = %v", err)
+			}
+			for _, action := range test.actions {
+				if !strings.Contains(err.Error(), action) {
+					t.Fatalf("conflict error does not name %q: %v", action, err)
+				}
+			}
+		})
+	}
+}
+
 func TestLoadConfigRejectsUnknownSettings(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "config.toml")
 	if err := os.WriteFile(path, []byte("refesh_interval = \"10s\"\n"), 0o600); err != nil {