Validate the context names in the "context" field of custom commands

If a custom command's "context" field contains a context name that
doesn't exist, lazygit panics when building the keybindings. This could
happen either because of a typo, or because a context is removed or
renamed in a later version. Prevent the panic by validating those names
at config load time, and rejecting the config as invalid there, like we
do for other config errors.

The gui package owns the list, but can't be imported from here, so it is
mirrored and a test over there ensures the copies stay in sync.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

pkg/config/user_config_validation.go

@@ -191,6 +191,51 @@ func validateCustomCommandKey(key Keybinding) error {
 	return nil
 }
 
+// ValidCustomCommandContexts lists the names a custom command's 'context' may
+// use. It mirrors context.AllContextKeys in the gui package, which this package
+// can't import; a test over there keeps the two in sync.
+var ValidCustomCommandContexts = []string{
+	"global",
+	"status",
+	"files",
+	"localBranches",
+	"remotes",
+	"worktrees",
+	"remoteBranches",
+	"tags",
+	"commits",
+	"reflogCommits",
+	"subCommits",
+	"commitFiles",
+	"stash",
+	"normal",
+	"normalSecondary",
+	"staging",
+	"stagingSecondary",
+	"patchBuilding",
+	"patchBuildingSecondary",
+	"mergeConflicts",
+	"menu",
+	"confirmation",
+	"prompt",
+	"search",
+	"commitMessage",
+	"submodules",
+	"suggestions",
+	"cmdLog",
+}
+
+func validateCustomCommandContext(context string) error {
+	for _, name := range strings.Split(context, ",") {
+		name = strings.TrimSpace(name)
+		if !slices.Contains(ValidCustomCommandContexts, name) {
+			return fmt.Errorf("Unknown context '%s' for custom command. Allowed values: %s",
+				name, strings.Join(ValidCustomCommandContexts, ", "))
+		}
+	}
+	return nil
+}
+
 func validateCustomCommands(customCommands []CustomCommand) error {
 	for _, customCommand := range customCommands {
 		if err := validateCustomCommandKey(customCommand.Key); err != nil {
@@ -216,6 +261,15 @@ func validateCustomCommands(customCommands []CustomCommand) error {
 				return err
 			}
 		} else {
+			// A command in a menu may leave the context out, in which case it is
+			// offered whatever is focused; a top-level one may not, but that is
+			// only noticed when the keybindings are built.
+			if customCommand.Context != "" {
+				if err := validateCustomCommandContext(customCommand.Context); err != nil {
+					return err
+				}
+			}
+
 			for _, prompt := range customCommand.Prompts {
 				if err := validateCustomCommandPrompt(prompt); err != nil {
 					return err

pkg/config/user_config_validation_test.go

@@ -225,6 +225,43 @@ func TestUserConfigValidate_enums(t *testing.T) {
 				{value: "invalid_value", valid: false},
 			},
 		},
+		{
+			name: "Custom command context",
+			setup: func(config *UserConfig, value string) {
+				config.CustomCommands = []CustomCommand{
+					{
+						Context: value,
+					},
+				}
+			},
+			testCases: []testCase{
+				{value: "", valid: true},
+				{value: "global", valid: true},
+				{value: "commits", valid: true},
+				{value: "commits, subCommits", valid: true},
+				{value: "commits,subCommits", valid: true},
+				{value: "invalid_value", valid: false},
+				{value: "commits, invalid_value", valid: false},
+			},
+		},
+		{
+			name: "Custom command context in a sub menu",
+			setup: func(config *UserConfig, value string) {
+				config.CustomCommands = []CustomCommand{
+					{
+						Key: Keybinding{"X"},
+						CommandMenu: []CustomCommand{
+							{Key: Keybinding{"1"}, Command: "echo 'hello'", Context: value},
+						},
+					},
+				}
+			},
+			testCases: []testCase{
+				{value: "", valid: true},
+				{value: "commits", valid: true},
+				{value: "invalid_value", valid: false},
+			},
+		},
 		{
 			name: "Custom command sub menu",
 			setup: func(config *UserConfig, _ string) {

pkg/gui/context/context_test.go

@@ -0,0 +1,22 @@
+package context
+
+import (
+	"testing"
+
+	"github.com/jesseduffield/lazygit/pkg/config"
+	"github.com/jesseduffield/lazygit/pkg/gui/types"
+	"github.com/samber/lo"
+	"github.com/stretchr/testify/assert"
+)
+
+// The config package validates a custom command's context against its own copy of
+// these names, being unable to import this package. A name in one list but not the
+// other would be either a context that validation rejects although you can bind to
+// it, or one it accepts although binding to it exits lazygit.
+func TestValidCustomCommandContextsMatchesAllContextKeys(t *testing.T) {
+	keys := lo.Map(AllContextKeys, func(key types.ContextKey, _ int) string {
+		return string(key)
+	})
+
+	assert.Equal(t, keys, config.ValidCustomCommandContexts)
+}