pull errors out of package scope and store sentinel errors on the gui struct

5 files changed, 49 insertions, 44 deletions

diff --git a/pkg/commands/os.go b/pkg/commands/os.go
index 9f9819a5a..d4ea75e74 100644
--- a/pkg/commands/os.go
+++ b/pkg/commands/os.go
@@ -14,13 +14,6 @@ import (
 	gitconfig "github.com/tcnksm/go-gitconfig"
 )
 
-var (
-	// ErrNoOpenCommand : When we don't know which command to use to open a file
-	ErrNoOpenCommand = errors.New("Unsure what command to use to open this file")
-	// ErrNoEditorDefined : When we can't find an editor to edit a file
-	ErrNoEditorDefined = errors.New("No editor defined in $VISUAL, $EDITOR, or git config")
-)
-
 // Platform stores the os state
 type Platform struct {
 	os           string
@@ -113,7 +106,7 @@ func (c *OSCommand) GetOpenCommand() (string, string, error) {
 			return name, trail, nil
 		}
 	}
-	return "", "", ErrNoOpenCommand
+	return "", "", errors.New("Unsure what command to use to open this file")
 }
 
 // VsCodeOpenFile opens the file in code, with the -r flag to open in the
@@ -157,7 +150,7 @@ func (c *OSCommand) EditFile(filename string) (*exec.Cmd, error) {
 		}
 	}
 	if editor == "" {
-		return nil, ErrNoEditorDefined
+		return nil, errors.New("No editor defined in $VISUAL, $EDITOR, or git config")
 	}
 	return c.PrepareSubProcess(editor, filename)
 }
diff --git a/pkg/gui/commit_message_panel.go b/pkg/gui/commit_message_panel.go
index 854732817..599c80186 100644
--- a/pkg/gui/commit_message_panel.go
+++ b/pkg/gui/commit_message_panel.go
@@ -12,13 +12,13 @@ func (gui *Gui) handleCommitConfirm(g *gocui.Gui, v *gocui.View) error {
 	sub, err := gui.GitCommand.Commit(g, message)
 	if err != nil {
 		// TODO need to find a way to send through this error
-		if err != ErrSubProcess {
+		if err != gui.Errors.ErrSubProcess {
 			return gui.createErrorPanel(g, err.Error())
 		}
 	}
 	if sub != nil {
 		gui.SubProcess = sub
-		return ErrSubProcess
+		return gui.Errors.ErrSubProcess
 	}
 	gui.refreshFiles(g)
 	v.Clear()
diff --git a/pkg/gui/commits_panel.go b/pkg/gui/commits_panel.go
index 60ae1c315..4f5ae2afc 100644
--- a/pkg/gui/commits_panel.go
+++ b/pkg/gui/commits_panel.go
@@ -8,11 +8,6 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/commands"
 )
 
-var (
-	// ErrNoCommits : When no commits are found for the branch
-	ErrNoCommits = errors.New("No commits for this branch")
-)
-
 func (gui *Gui) refreshCommits(g *gocui.Gui) error {
 	g.Update(func(*gocui.Gui) error {
 		gui.State.Commits = gui.GitCommand.GetCommits()
@@ -79,7 +74,7 @@ func (gui *Gui) handleCommitSelect(g *gocui.Gui, v *gocui.View) error {
 	}
 	commit, err := gui.getSelectedCommit(g)
 	if err != nil {
-		if err != ErrNoCommits {
+		if err != errors.New("No commits for this branch") {
 			return err
 		}
 		return gui.renderString(g, "main", "No commits for this branch")
@@ -165,7 +160,7 @@ func (gui *Gui) getSelectedCommit(g *gocui.Gui) (commands.Commit, error) {
 		panic(err)
 	}
 	if len(gui.State.Commits) == 0 {
-		return commands.Commit{}, ErrNoCommits
+		return commands.Commit{}, errors.New("No commits for this branch")
 	}
 	lineNumber := gui.getItemPosition(v)
 	if lineNumber > len(gui.State.Commits)-1 {
diff --git a/pkg/gui/files_panel.go b/pkg/gui/files_panel.go
index 8c4c5cb6f..312c06554 100644
--- a/pkg/gui/files_panel.go
+++ b/pkg/gui/files_panel.go
@@ -7,7 +7,6 @@ import (
 
 	// "strings"
 
-	"errors"
 	"os/exec"
 	"strings"
 
@@ -16,11 +15,6 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/commands"
 )
 
-var (
-	errNoFiles    = errors.New(lang.SLocalize("NoChangedFiles", "No changed files"))
-	errNoUsername = errors.New(lang.SLocalize("NoUsernameSetErr", `No username set. Please do: git config --global user.name "Your Name"`))
-)
-
 func (gui *Gui) stagedFiles() []commands.File {
 	files := gui.State.Files
 	result := make([]commands.File, 0)
@@ -54,7 +48,7 @@ func (gui *Gui) stageSelectedFile(g *gocui.Gui) error {
 func (gui *Gui) handleFilePress(g *gocui.Gui, v *gocui.View) error {
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err == errNoFiles {
+		if err == gui.Errors.ErrNoFiles {
 			return nil
 		}
 		return err
@@ -80,16 +74,16 @@ func (gui *Gui) handleFilePress(g *gocui.Gui, v *gocui.View) error {
 func (gui *Gui) handleAddPatch(g *gocui.Gui, v *gocui.View) error {
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err == errNoFiles {
+		if err == gui.Errors.ErrNoFiles {
 			return nil
 		}
 		return err
 	}
 	if !file.HasUnstagedChanges {
-		return gui.createErrorPanel(g, lang.SLocalize("FileHasNoUnstagedChanges", "File has no unstaged changes to add"))
+		return gui.createErrorPanel(g, gui.Tr.SLocalize("FileHasNoUnstagedChanges", "File has no unstaged changes to add"))
 	}
 	if !file.Tracked {
-		return gui.createErrorPanel(g, lang.SLocalize("CannotGitAdd", "Cannot git add --patch untracked files"))
+		return gui.createErrorPanel(g, gui.Tr.SLocalize("CannotGitAdd", "Cannot git add --patch untracked files"))
 	}
 	sub, err := gui.GitCommand.AddPatch(file.Name)
 	if err != nil {
@@ -101,7 +95,7 @@ func (gui *Gui) handleAddPatch(g *gocui.Gui, v *gocui.View) error {
 
 func (gui *Gui) getSelectedFile(g *gocui.Gui) (commands.File, error) {
 	if len(gui.State.Files) == 0 {
-		return commands.File{}, errNoFiles
+		return commands.File{}, gui.Errors.ErrNoFiles
 	}
 	filesView, err := g.View("files")
 	if err != nil {
@@ -114,7 +108,7 @@ func (gui *Gui) getSelectedFile(g *gocui.Gui) (commands.File, error) {
 func (gui *Gui) handleFileRemove(g *gocui.Gui, v *gocui.View) error {
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err == errNoFiles {
+		if err == gui.Errors.ErrNoFiles {
 			return nil
 		}
 		return err
@@ -139,7 +133,7 @@ func (gui *Gui) handleIgnoreFile(g *gocui.Gui, v *gocui.View) error {
 		return gui.createErrorPanel(g, err.Error())
 	}
 	if file.Tracked {
-		return gui.createErrorPanel(g, lang.SLocalize("CantIgnoreTrackFiles", "Cannot ignore tracked files"))
+		return gui.createErrorPanel(g, gui.Tr.SLocalize("CantIgnoreTrackFiles", "Cannot ignore tracked files"))
 	}
 	gui.GitCommand.Ignore(file.Name)
 	return gui.refreshFiles(g)
@@ -175,7 +169,7 @@ func (gui *Gui) renderfilesOptions(g *gocui.Gui, file *commands.File) error {
 func (gui *Gui) handleFileSelect(g *gocui.Gui, v *gocui.View) error {
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err != errNoFiles {
+		if err != gui.Errors.ErrNoFiles {
 			return err
 		}
 		gui.renderString(g, "main", "No changed files")
@@ -230,7 +224,7 @@ func (gui *Gui) PrepareSubProcess(g *gocui.Gui, commands ...string) error {
 func (gui *Gui) genericFileOpen(g *gocui.Gui, v *gocui.View, open func(string) (*exec.Cmd, error)) error {
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err != errNoFiles {
+		if err != gui.Errors.ErrNoFiles {
 			return err
 		}
 		return nil
@@ -303,7 +297,7 @@ func (gui *Gui) renderFile(file commands.File, filesView *gocui.View) {
 func (gui *Gui) catSelectedFile(g *gocui.Gui) (string, error) {
 	item, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err != errNoFiles {
+		if err != gui.Errors.ErrNoFiles {
 			return "", err
 		}
 		return "", gui.renderString(g, "main", "No file to display")
@@ -369,7 +363,7 @@ func (gui *Gui) handleSwitchToMerge(g *gocui.Gui, v *gocui.View) error {
 	}
 	file, err := gui.getSelectedFile(g)
 	if err != nil {
-		if err != errNoFiles {
+		if err != gui.Errors.ErrNoFiles {
 			return err
 		}
 		return nil
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index bf8360f72..4e8382eae 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -25,11 +25,29 @@ import (
 // OverlappingEdges determines if panel edges overlap
 var OverlappingEdges = false
 
-// ErrSubProcess tells us we're switching to a subprocess so we need to
-// close the Gui until it is finished
-var (
-	ErrSubProcess = errors.New("running subprocess")
-)
+// SentinelErrors are the errors that have special meaning and need to be checked
+// by calling functions. The less of these, the better
+type SentinelErrors struct {
+	ErrSubProcess error
+	ErrNoFiles    error
+}
+
+// GenerateSentinelErrors makes the sentinel errors for the gui. We're defining it here
+// because we can't do package-scoped errors with localization, and also because
+// it seems like package-scoped variables are bad in general
+// https://dave.cheney.net/2017/06/11/go-without-package-scoped-variables
+// In the future it would be good to implement some of the recommendations of
+// that article. For now, if we don't need an error to be a sentinel, we will just
+// define it inline. This has implications for error messages that pop up everywhere
+// in that we'll be duplicating the default values. We may need to look at
+// having a default localisation bundle defined, and just using keys-only when
+// localising things in the code.
+func (gui *Gui) GenerateSentinelErrors() {
+	gui.Errors = SentinelErrors{
+		ErrSubProcess: errors.New("running subprocess"),
+		ErrNoFiles:    errors.New(gui.Tr.SLocalize("NoChangedFiles", "No changed files")),
+	}
+}
 
 // Gui wraps the gocui Gui object which handles rendering and events
 type Gui struct {
@@ -41,6 +59,7 @@ type Gui struct {
 	SubProcess *exec.Cmd
 	State      guiState
 	Tr         *i18n.Localizer
+	Errors     SentinelErrors
 }
 
 type guiState struct {
@@ -70,17 +89,21 @@ func NewGui(log *logrus.Logger, gitCommand *commands.GitCommand, oSCommand *comm
 		Conflicts:     make([]commands.Conflict, 0),
 		EditHistory:   stack.New(),
 		Platform:      *oSCommand.Platform,
-		Version:       "test version", // TODO: send version in
+		Version:       version,
 	}
 
-	return &Gui{
+	gui := &Gui{
 		Log:        log,
 		GitCommand: gitCommand,
 		OSCommand:  oSCommand,
 		Version:    version,
 		State:      initialState,
 		Tr:         tr,
-	}, nil
+	}
+
+	gui.GenerateSentinelErrors()
+
+	return gui, nil
 }
 
 func (gui *Gui) scrollUpMain(g *gocui.Gui, v *gocui.View) error {
@@ -313,7 +336,7 @@ func (gui *Gui) RunWithSubprocesses() {
 		if err := gui.Run(); err != nil {
 			if err == gocui.ErrQuit {
 				break
-			} else if err == ErrSubProcess {
+			} else if err == gui.Errors.ErrSubProcess {
 				gui.SubProcess.Stdin = os.Stdin
 				gui.SubProcess.Stdout = os.Stdout
 				gui.SubProcess.Stderr = os.Stderr