Implement "Ignore by file extension" command

That works exactly like the "ignore" command
But instead of ignoring a file it ignores *.<extension> of the selected
file

pkg/config/user_config.go

@@ -455,6 +455,7 @@ type KeybindingFilesConfig struct {
 	FindBaseCommitForFixup   string `yaml:"findBaseCommitForFixup"`
 	ConfirmDiscard           string `yaml:"confirmDiscard"`
 	IgnoreFile               string `yaml:"ignoreFile"`
+	IgnoreFileExtension      string `yaml:"ignoreFileExtension"`
 	RefreshFiles             string `yaml:"refreshFiles"`
 	StashAllChanges          string `yaml:"stashAllChanges"`
 	ViewStashOptions         string `yaml:"viewStashOptions"`
@@ -928,6 +929,7 @@ func GetDefaultConfig() *UserConfig {
 				CommitChangesWithEditor:  "C",
 				FindBaseCommitForFixup:   "<c-f>",
 				IgnoreFile:               "i",
+				IgnoreFileExtension:      "I",
 				RefreshFiles:             "r",
 				StashAllChanges:          "s",
 				ViewStashOptions:         "S",

pkg/gui/controllers/files_controller.go

@@ -109,6 +109,12 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 			Description:       self.c.Tr.Actions.IgnoreExcludeFile,
 			OpensMenu:         true,
 		},
+		{
+			Key:               opts.GetKey(opts.Config.Files.IgnoreFileExtension),
+			Handler:           self.withItem(self.ignoreExtension),
+			GetDisabledReason: self.require(self.singleItemSelected()),
+			Description:       self.c.Tr.IgnoreFileExtension,
+		},
 		{
 			Key:         opts.GetKey(opts.Config.Files.RefreshFiles),
 			Handler:     self.refresh,
@@ -657,6 +663,24 @@ func (self *FilesController) ignore(node *filetree.FileNode) error {
 	return self.ignoreOrExcludeFile(node, self.c.Tr.IgnoreTracked, self.c.Tr.IgnoreTrackedPrompt, self.c.Tr.Actions.IgnoreExcludeFile, self.c.Git().WorkingTree.Ignore)
 }
 
+func (self *FilesController) ignoreExtension(node *filetree.FileNode) error {
+	if node.GetPath() == ".gitignore" {
+		return errors.New(self.c.Tr.Actions.IgnoreFileErr)
+	}
+
+	path := node.GetPath()
+	ext := filepath.Ext(path)
+	if ext == "" {
+		return fmt.Errorf("No file extension to ignore")
+	}
+
+	pattern := "*" + ext
+
+	return self.ignoreOrExcludeFile(node, self.c.Tr.IgnoreTracked, self.c.Tr.IgnoreTrackedPrompt, self.c.Tr.Actions.IgnoreExcludeFile, func(string) error {
+		return self.c.Git().WorkingTree.Ignore(pattern)
+	})
+}
+
 func (self *FilesController) exclude(node *filetree.FileNode) error {
 	if node.GetPath() == ".gitignore" {
 		return errors.New(self.c.Tr.Actions.ExcludeGitIgnoreErr)
@@ -679,6 +703,16 @@ func (self *FilesController) ignoreOrExcludeMenu(node *filetree.FileNode) error
 				},
 				Key: 'i',
 			},
+			{
+				LabelColumns: []string{self.c.Tr.IgnoreFileExtension},
+				OnPress: func() error {
+					if err := self.ignoreExtension(node); err != nil {
+						return err
+					}
+					return nil
+				},
+				Key: 'I',
+			},
 			{
 				LabelColumns: []string{self.c.Tr.ExcludeFile},
 				OnPress: func() error {

pkg/i18n/english.go

@@ -252,6 +252,7 @@ type TranslationSet struct {
 	OpenFileTooltip                       string
 	OpenInEditor                          string
 	IgnoreFile                            string
+	IgnoreFileExtension                   string
 	ExcludeFile                           string
 	RefreshFiles                          string
 	Merge                                 string
@@ -1291,6 +1292,7 @@ func EnglishTranslationSet() *TranslationSet {
 		OpenFileTooltip:                      "Open file in default application.",
 		OpenInEditor:                         "Open in editor",
 		IgnoreFile:                           `Add to .gitignore`,
+		IgnoreFileExtension:                  `Add extension to .gitignore`,
 		ExcludeFile:                          `Add to .git/info/exclude`,
 		RefreshFiles:                         `Refresh files`,
 		Merge:                                `Merge`,