Use substring filtering instead of fuzzy filtering by default (#3376)

By default we now search for substrings; you can search for multiple
substrings by separating them with spaces. Add a config option
`gui.filterMode` that can be set to 'fuzzy' to switch back to the
previous behavior.

Addresses #3373.

Author: stefanhaller

docs/Config.md

@@ -86,6 +86,7 @@ gui:
   border: 'rounded' # one of 'single' | 'double' | 'rounded' | 'hidden'
   animateExplosion: true # shows an explosion animation when nuking the working tree
   portraitMode: 'auto' # one of 'auto' | 'never' | 'always'
+  filterMode: 'substring' # one of 'substring' | 'fuzzy'; see 'Filtering' section below
 git:
   paging:
     colorArg: always
@@ -374,6 +375,12 @@ That's the behavior when `gui.scrollOffBehavior` is set to "margin" (the default
 
 This setting applies both to all list views (e.g. commits and branches etc), and to the staging view.
 
+## Filtering
+
+We have two ways to filter things, substring matching (the default) and fuzzy searching. With substring matching, the text you enter gets searched for verbatim (usually case-insensitive, except when your filter string contains uppercase letters, in which case we search case-sensitively). You can search for multiple non-contiguous substrings by separating them with spaces; for example, "int test" will match "integration-testing". All substrings have to match, but not necessarily in the given order.
+
+Fuzzy searching is smarter in that it allows every letter of the filter string to match anywhere in the text (only in order though), assigning a weight to the quality of the match and sorting by that order. This has the advantage that it allows typing "clt" to match "commit_loader_test" (letters at the beginning of subwords get more weight); but it has the disadvantage that it tends to return lots of irrelevant results, especially with short filter strings.
+
 ## Color Attributes
 
 For color attributes you can choose an array of attributes (with max one color attribute)

pkg/config/user_config.go

@@ -142,6 +142,13 @@ type GuiConfig struct {
 	// Whether to stack UI components on top of each other.
 	// One of 'auto' (default) | 'always' | 'never'
 	PortraitMode string `yaml:"portraitMode"`
+	// How things are filtered when typing '/'.
+	// One of 'substring' (default) | 'fuzzy'
+	FilterMode string `yaml:"filterMode" jsonschema:"enum=substring,enum=fuzzy"`
+}
+
+func (c *GuiConfig) UseFuzzySearch() bool {
+	return c.FilterMode == "fuzzy"
 }
 
 type ThemeConfig struct {
@@ -660,6 +667,7 @@ func GetDefaultConfig() *UserConfig {
 			Border:                    "rounded",
 			AnimateExplosion:          true,
 			PortraitMode:              "auto",
+			FilterMode:                "substring",
 		},
 		Git: GitConfig{
 			Paging: PagingConfig{

pkg/gui/context/branches_context.go

@@ -22,7 +22,6 @@ func NewBranchesContext(c *ContextCommon) *BranchesContext {
 		func(branch *models.Branch) []string {
 			return []string{branch.Name}
 		},
-		func() bool { return c.AppState.LocalBranchSortOrder != "alphabetical" },
 	)
 
 	getDisplayStrings := func(_ int, _ int) [][]string {

pkg/gui/context/filtered_list.go

@@ -1,7 +1,6 @@
 package context
 
 import (
-	"slices"
 	"strings"
 
 	"github.com/jesseduffield/lazygit/pkg/utils"
@@ -17,40 +16,33 @@ type FilteredList[T any] struct {
 	getFilterFields func(T) []string
 	filter          string
 
-	// Normally, filtered items are presented sorted by best match. If this
-	// function returns true, they retain their original sort order instead;
-	// this is useful for lists that show items sorted by date, for example.
-	// Leaving this nil is equivalent to returning false.
-	shouldRetainSortOrder func() bool
-
 	mutex *deadlock.Mutex
 }
 
-func NewFilteredList[T any](getList func() []T, getFilterFields func(T) []string, shouldRetainSortOrder func() bool) *FilteredList[T] {
+func NewFilteredList[T any](getList func() []T, getFilterFields func(T) []string) *FilteredList[T] {
 	return &FilteredList[T]{
-		getList:               getList,
-		getFilterFields:       getFilterFields,
-		shouldRetainSortOrder: shouldRetainSortOrder,
-		mutex:                 &deadlock.Mutex{},
+		getList:         getList,
+		getFilterFields: getFilterFields,
+		mutex:           &deadlock.Mutex{},
 	}
 }
 
 func (self *FilteredList[T]) GetFilter() string {
 	return self.filter
 }
 
-func (self *FilteredList[T]) SetFilter(filter string) {
+func (self *FilteredList[T]) SetFilter(filter string, useFuzzySearch bool) {
 	self.filter = filter
 
-	self.applyFilter()
+	self.applyFilter(useFuzzySearch)
 }
 
 func (self *FilteredList[T]) ClearFilter() {
-	self.SetFilter("")
+	self.SetFilter("", false)
 }
 
-func (self *FilteredList[T]) ReApplyFilter() {
-	self.applyFilter()
+func (self *FilteredList[T]) ReApplyFilter(useFuzzySearch bool) {
+	self.applyFilter(useFuzzySearch)
 }
 
 func (self *FilteredList[T]) IsFiltering() bool {
@@ -84,7 +76,7 @@ func (self *fuzzySource[T]) Len() int {
 	return len(self.list)
 }
 
-func (self *FilteredList[T]) applyFilter() {
+func (self *FilteredList[T]) applyFilter(useFuzzySearch bool) {
 	self.mutex.Lock()
 	defer self.mutex.Unlock()
 
@@ -96,13 +88,10 @@ func (self *FilteredList[T]) applyFilter() {
 			getFilterFields: self.getFilterFields,
 		}
 
-		matches := fuzzy.FindFrom(self.filter, source)
+		matches := utils.FindFrom(self.filter, source, useFuzzySearch)
 		self.filteredIndices = lo.Map(matches, func(match fuzzy.Match, _ int) int {
 			return match.Index
 		})
-		if self.shouldRetainSortOrder != nil && self.shouldRetainSortOrder() {
-			slices.Sort(self.filteredIndices)
-		}
 	}
 }
 

pkg/gui/context/filtered_list_view_model.go

@@ -6,8 +6,8 @@ type FilteredListViewModel[T HasID] struct {
 	*SearchHistory
 }
 
-func NewFilteredListViewModel[T HasID](getList func() []T, getFilterFields func(T) []string, shouldRetainSortOrder func() bool) *FilteredListViewModel[T] {
-	filteredList := NewFilteredList(getList, getFilterFields, shouldRetainSortOrder)
+func NewFilteredListViewModel[T HasID](getList func() []T, getFilterFields func(T) []string) *FilteredListViewModel[T] {
+	filteredList := NewFilteredList(getList, getFilterFields)
 
 	self := &FilteredListViewModel[T]{
 		FilteredList:  filteredList,

pkg/gui/context/menu_context.go

@@ -61,10 +61,6 @@ func NewMenuViewModel(c *ContextCommon) *MenuViewModel {
 	self.FilteredListViewModel = NewFilteredListViewModel(
 		func() []*types.MenuItem { return self.menuItems },
 		func(item *types.MenuItem) []string { return item.LabelColumns },
-		// The only menu that the user is likely to filter in is the keybindings
-		// menu; retain the sort order in that one because this allows us to
-		// keep the section headers while filtering:
-		func() bool { return true },
 	)
 
 	return self
@@ -99,6 +95,13 @@ func (self *MenuViewModel) GetDisplayStrings(_ int, _ int) [][]string {
 }
 
 func (self *MenuViewModel) GetNonModelItems() []*NonModelItem {
+	// Don't display section headers when we are filtering, and the filter mode
+	// is fuzzy. The reason is that filtering changes the order of the items
+	// (they are sorted by best match), so all the sections would be messed up.
+	if self.FilteredListViewModel.IsFiltering() && self.c.UserConfig.Gui.UseFuzzySearch() {
+		return []*NonModelItem{}
+	}
+
 	result := []*NonModelItem{}
 	menuItems := self.FilteredListViewModel.GetItems()
 	var prevSection *types.MenuSection = nil

pkg/gui/context/reflog_commits_context.go

@@ -24,7 +24,6 @@ func NewReflogCommitsContext(c *ContextCommon) *ReflogCommitsContext {
 		func(commit *models.Commit) []string {
 			return []string{commit.ShortSha(), commit.Name}
 		},
-		func() bool { return true },
 	)
 
 	getDisplayStrings := func(_ int, _ int) [][]string {

pkg/gui/context/remote_branches_context.go

@@ -26,7 +26,6 @@ func NewRemoteBranchesContext(
 		func(remoteBranch *models.RemoteBranch) []string {
 			return []string{remoteBranch.Name}
 		},
-		func() bool { return c.AppState.RemoteBranchSortOrder != "alphabetical" },
 	)
 
 	getDisplayStrings := func(_ int, _ int) [][]string {

pkg/gui/context/remotes_context.go

@@ -22,7 +22,6 @@ func NewRemotesContext(c *ContextCommon) *RemotesContext {
 		func(remote *models.Remote) []string {
 			return []string{remote.Name}
 		},
-		nil,
 	)
 
 	getDisplayStrings := func(_ int, _ int) [][]string {

pkg/gui/context/stash_context.go

@@ -24,7 +24,6 @@ func NewStashContext(
 		func(stashEntry *models.StashEntry) []string {
 			return []string{stashEntry.Name}
 		},
-		func() bool { return true },
 	)
 
 	getDisplayStrings := func(_ int, _ int) [][]string {