Support using command output directly in menuFromCommand custom command prompt

The menuFromCommand option is a little complicated, so I'm adding an easy way to just use the command output directly,
where each line becomes a suggestion, as-is.

Now that we support suggestions in the input prompt, there's less of a need for menuFromCommand, but it probably still
serves some purpose.

In future I want to support this filter/valueFormat/labelFormat thing for suggestions too. I would like to think a little more
about the interface though: is using a regex like we currently do really the simplest approach?

pkg/gui/services/custom_commands/handler_creator.go

@@ -210,7 +210,7 @@ func (self *HandlerCreator) menuPromptFromCommand(prompt *config.CustomCommandPr
 		return self.c.Error(err)
 	}
 
-	menuItems := slices.Map(candidates, func(candidate *commandMenuEntry) *types.MenuItem {
+	menuItems := slices.Map(candidates, func(candidate *commandMenuItem) *types.MenuItem {
 		return &types.MenuItem{
 			LabelColumns: []string{candidate.label},
 			OnPress: func() error {

pkg/gui/services/custom_commands/menu_generator.go

@@ -22,12 +22,41 @@ func NewMenuGenerator(c *common.Common) *MenuGenerator {
 	return &MenuGenerator{c: c}
 }
 
-type commandMenuEntry struct {
+type commandMenuItem struct {
 	label string
 	value string
 }
 
-func (self *MenuGenerator) call(commandOutput, filter, valueFormat, labelFormat string) ([]*commandMenuEntry, error) {
+func (self *MenuGenerator) call(commandOutput, filter, valueFormat, labelFormat string) ([]*commandMenuItem, error) {
+	menuItemFromLine, err := self.getMenuItemFromLinefn(filter, valueFormat, labelFormat)
+	if err != nil {
+		return nil, err
+	}
+
+	menuItems := []*commandMenuItem{}
+	for _, line := range strings.Split(commandOutput, "\n") {
+		if line == "" {
+			continue
+		}
+
+		menuItem, err := menuItemFromLine(line)
+		if err != nil {
+			return nil, err
+		}
+		menuItems = append(menuItems, menuItem)
+	}
+
+	return menuItems, nil
+}
+
+func (self *MenuGenerator) getMenuItemFromLinefn(filter string, valueFormat string, labelFormat string) (func(line string) (*commandMenuItem, error), error) {
+	if filter == "" && valueFormat == "" && labelFormat == "" {
+		// showing command output lines as-is in suggestions panel
+		return func(line string) (*commandMenuItem, error) {
+			return &commandMenuItem{label: line, value: line}, nil
+		}, nil
+	}
+
 	regex, err := regexp.Compile(filter)
 	if err != nil {
 		return nil, errors.New("unable to parse filter regex, error: " + err.Error())
@@ -51,37 +80,25 @@ func (self *MenuGenerator) call(commandOutput, filter, valueFormat, labelFormat
 		labelTemplate = valueTemplate
 	}
 
-	candidates := []*commandMenuEntry{}
-	for _, line := range strings.Split(commandOutput, "\n") {
-		if line == "" {
-			continue
-		}
-
-		candidate, err := self.generateMenuCandidate(
+	return func(line string) (*commandMenuItem, error) {
+		return self.generateMenuItem(
 			line,
 			regex,
 			valueTemplate,
 			labelTemplate,
 		)
-		if err != nil {
-			return nil, err
-		}
-
-		candidates = append(candidates, candidate)
-	}
-
-	return candidates, err
+	}, nil
 }
 
-func (self *MenuGenerator) generateMenuCandidate(
+func (self *MenuGenerator) generateMenuItem(
 	line string,
 	regex *regexp.Regexp,
 	valueTemplate *TrimmerTemplate,
 	labelTemplate *TrimmerTemplate,
-) (*commandMenuEntry, error) {
+) (*commandMenuItem, error) {
 	tmplData := self.parseLine(line, regex)
 
-	entry := &commandMenuEntry{}
+	entry := &commandMenuItem{}
 
 	var err error
 	entry.value, err = valueTemplate.execute(tmplData)

pkg/gui/services/custom_commands/menu_generator_test.go

@@ -14,7 +14,7 @@ func TestMenuGenerator(t *testing.T) {
 		filter      string
 		valueFormat string
 		labelFormat string
-		test        func([]*commandMenuEntry, error)
+		test        func([]*commandMenuItem, error)
 	}
 
 	scenarios := []scenario{
@@ -24,7 +24,7 @@ func TestMenuGenerator(t *testing.T) {
 			"(?P<remote>[a-z_]+)/(?P<branch>.*)",
 			"{{ .branch }}",
 			"Remote: {{ .remote }}",
-			func(actualEntry []*commandMenuEntry, err error) {
+			func(actualEntry []*commandMenuItem, err error) {
 				assert.NoError(t, err)
 				assert.EqualValues(t, "pr-1", actualEntry[0].value)
 				assert.EqualValues(t, "Remote: upstream", actualEntry[0].label)
@@ -36,7 +36,7 @@ func TestMenuGenerator(t *testing.T) {
 			"(?P<remote>[a-z]*)/(?P<branch>.*)",
 			"{{ .branch }}|{{ .remote }}",
 			"",
-			func(actualEntry []*commandMenuEntry, err error) {
+			func(actualEntry []*commandMenuItem, err error) {
 				assert.NoError(t, err)
 				assert.EqualValues(t, "pr-1|upstream", actualEntry[0].value)
 				assert.EqualValues(t, "pr-1|upstream", actualEntry[0].label)
@@ -48,12 +48,36 @@ func TestMenuGenerator(t *testing.T) {
 			"(?P<remote>[a-z]*)/(?P<branch>.*)",
 			"{{ .group_2 }}|{{ .group_1 }}",
 			"Remote: {{ .group_1 }}",
-			func(actualEntry []*commandMenuEntry, err error) {
+			func(actualEntry []*commandMenuItem, err error) {
 				assert.NoError(t, err)
 				assert.EqualValues(t, "pr-1|upstream", actualEntry[0].value)
 				assert.EqualValues(t, "Remote: upstream", actualEntry[0].label)
 			},
 		},
+		{
+			"No named groups",
+			"upstream/pr-1",
+			"([a-z]*)/(.*)",
+			"{{ .group_2 }}|{{ .group_1 }}",
+			"Remote: {{ .group_1 }}",
+			func(actualEntry []*commandMenuItem, err error) {
+				assert.NoError(t, err)
+				assert.EqualValues(t, "pr-1|upstream", actualEntry[0].value)
+				assert.EqualValues(t, "Remote: upstream", actualEntry[0].label)
+			},
+		},
+		{
+			"No filter",
+			"upstream/pr-1",
+			"",
+			"",
+			"",
+			func(actualEntry []*commandMenuItem, err error) {
+				assert.NoError(t, err)
+				assert.EqualValues(t, "upstream/pr-1", actualEntry[0].value)
+				assert.EqualValues(t, "upstream/pr-1", actualEntry[0].label)
+			},
+		},
 	}
 
 	for _, s := range scenarios {