more generics

11 files changed, 218 insertions, 106 deletions

diff --git a/pkg/commands/git_commands/working_tree.go b/pkg/commands/git_commands/working_tree.go
index f594a639b..08e247459 100644
--- a/pkg/commands/git_commands/working_tree.go
+++ b/pkg/commands/git_commands/working_tree.go
@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/go-errors/errors"
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/commands/loaders"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
@@ -46,10 +47,9 @@ func (self *WorkingTreeCommands) StageFile(path string) error {
 }
 
 func (self *WorkingTreeCommands) StageFiles(paths []string) error {
-	quotedPaths := make([]string, len(paths))
-	for i, path := range paths {
-		quotedPaths[i] = self.cmd.Quote(path)
-	}
+	quotedPaths := slices.Map(paths, func(path string) string {
+		return self.cmd.Quote(path)
+	})
 	return self.cmd.New(fmt.Sprintf("git add -- %s", strings.Join(quotedPaths, " "))).Run()
 }
 
diff --git a/pkg/commands/loaders/branches.go b/pkg/commands/loaders/branches.go
index 90480ca9a..682c23ad4 100644
--- a/pkg/commands/loaders/branches.go
+++ b/pkg/commands/loaders/branches.go
@@ -66,13 +66,13 @@ outer:
 			if strings.EqualFold(reflogBranch.Name, branch.Name) {
 				branch.Recency = reflogBranch.Recency
 				branchesWithRecency = append(branchesWithRecency, branch)
-				branches = append(branches[0:j], branches[j+1:]...)
+				branches = slices.Remove(branches, j)
 				continue outer
 			}
 		}
 	}
 
-	branches = append(branchesWithRecency, branches...)
+	branches = slices.Prepend(branches, branchesWithRecency...)
 
 	foundHead := false
 	for i, branch := range branches {
@@ -159,7 +159,7 @@ func (self *BranchLoader) obtainBranches() []*models.Branch {
 	trimmedOutput := strings.TrimSpace(output)
 	outputLines := strings.Split(trimmedOutput, "\n")
 
-	branches := slices.FilterMap(outputLines, func(line string) (*models.Branch, bool) {
+	return slices.FilterMap(outputLines, func(line string) (*models.Branch, bool) {
 		if line == "" {
 			return nil, false
 		}
@@ -174,8 +174,6 @@ func (self *BranchLoader) obtainBranches() []*models.Branch {
 
 		return obtainBranch(split), true
 	})
-
-	return branches
 }
 
 // TODO: only look at the new reflog commits, and otherwise store the recencies in
@@ -184,17 +182,21 @@ func (self *BranchLoader) obtainReflogBranches(reflogCommits []*models.Commit) [
 	foundBranches := set.New[string]()
 	re := regexp.MustCompile(`checkout: moving from ([\S]+) to ([\S]+)`)
 	reflogBranches := make([]*models.Branch, 0, len(reflogCommits))
+
 	for _, commit := range reflogCommits {
-		if match := re.FindStringSubmatch(commit.Name); len(match) == 3 {
-			recency := utils.UnixToTimeAgo(commit.UnixTimestamp)
-			for _, branchName := range match[1:] {
-				if !foundBranches.Includes(branchName) {
-					foundBranches.Add(branchName)
-					reflogBranches = append(reflogBranches, &models.Branch{
-						Recency: recency,
-						Name:    branchName,
-					})
-				}
+		match := re.FindStringSubmatch(commit.Name)
+		if len(match) != 3 {
+			continue
+		}
+
+		recency := utils.UnixToTimeAgo(commit.UnixTimestamp)
+		for _, branchName := range match[1:] {
+			if !foundBranches.Includes(branchName) {
+				foundBranches.Add(branchName)
+				reflogBranches = append(reflogBranches, &models.Branch{
+					Recency: recency,
+					Name:    branchName,
+				})
 			}
 		}
 	}
diff --git a/pkg/commands/loaders/commit_files.go b/pkg/commands/loaders/commit_files.go
index 755db768d..d68571edb 100644
--- a/pkg/commands/loaders/commit_files.go
+++ b/pkg/commands/loaders/commit_files.go
@@ -4,9 +4,11 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
 	"github.com/jesseduffield/lazygit/pkg/common"
+	"github.com/samber/lo"
 )
 
 type CommitFileLoader struct {
@@ -33,25 +35,22 @@ func (self *CommitFileLoader) GetFilesInDiff(from string, to string, reverse boo
 		return nil, err
 	}
 
-	return self.getCommitFilesFromFilenames(filenames), nil
+	return getCommitFilesFromFilenames(filenames), nil
 }
 
-// filenames string is something like "file1\nfile2\nfile3"
-func (self *CommitFileLoader) getCommitFilesFromFilenames(filenames string) []*models.CommitFile {
-	commitFiles := make([]*models.CommitFile, 0)
-
+// filenames string is something like "MM\x00file1\x00MU\x00file2\x00AA\x00file3\x00"
+// so we need to split it by the null character and then map each status-name pair to a commit file
+func getCommitFilesFromFilenames(filenames string) []*models.CommitFile {
 	lines := strings.Split(strings.TrimRight(filenames, "\x00"), "\x00")
-	n := len(lines)
-	for i := 0; i < n-1; i += 2 {
-		// typical result looks like 'A my_file' meaning my_file was added
-		changeStatus := lines[i]
-		name := lines[i+1]
-
-		commitFiles = append(commitFiles, &models.CommitFile{
-			Name:         name,
-			ChangeStatus: changeStatus,
-		})
+	if len(lines) == 1 {
+		return []*models.CommitFile{}
 	}
 
-	return commitFiles
+	// typical result looks like 'A my_file' meaning my_file was added
+	return slices.Map(lo.Chunk(lines, 2), func(chunk []string) *models.CommitFile {
+		return &models.CommitFile{
+			ChangeStatus: chunk[0],
+			Name:         chunk[1],
+		}
+	})
 }
diff --git a/pkg/commands/loaders/commit_files_test.go b/pkg/commands/loaders/commit_files_test.go
new file mode 100644
index 000000000..a07390052
--- /dev/null
+++ b/pkg/commands/loaders/commit_files_test.go
@@ -0,0 +1,71 @@
+package loaders
+
+import (
+	"testing"
+
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetCommitFilesFromFilenames(t *testing.T) {
+	tests := []struct {
+		testName string
+		input    string
+		output   []*models.CommitFile
+	}{
+		{
+			testName: "no files",
+			input:    "",
+			output:   []*models.CommitFile{},
+		},
+		{
+			testName: "one file",
+			input:    "MM\x00Myfile\x00",
+			output: []*models.CommitFile{
+				{
+					Name:         "Myfile",
+					ChangeStatus: "MM",
+				},
+			},
+		},
+		{
+			testName: "two files",
+			input:    "MM\x00Myfile\x00M \x00MyOtherFile\x00",
+			output: []*models.CommitFile{
+				{
+					Name:         "Myfile",
+					ChangeStatus: "MM",
+				},
+				{
+					Name:         "MyOtherFile",
+					ChangeStatus: "M ",
+				},
+			},
+		},
+		{
+			testName: "three files",
+			input:    "MM\x00Myfile\x00M \x00MyOtherFile\x00 M\x00YetAnother\x00",
+			output: []*models.CommitFile{
+				{
+					Name:         "Myfile",
+					ChangeStatus: "MM",
+				},
+				{
+					Name:         "MyOtherFile",
+					ChangeStatus: "M ",
+				},
+				{
+					Name:         "YetAnother",
+					ChangeStatus: " M",
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.testName, func(t *testing.T) {
+			result := getCommitFilesFromFilenames(test.input)
+			assert.Equal(t, test.output, result)
+		})
+	}
+}
diff --git a/pkg/commands/loaders/commits.go b/pkg/commands/loaders/commits.go
index 187a13bb0..20721be42 100644
--- a/pkg/commands/loaders/commits.go
+++ b/pkg/commands/loaders/commits.go
@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
 	"github.com/jesseduffield/lazygit/pkg/commands/types/enums"
@@ -200,10 +201,9 @@ func (self *CommitLoader) getHydratedRebasingCommits(rebaseMode enums.RebaseMode
 		return nil, nil
 	}
 
-	commitShas := make([]string, len(commits))
-	for i, commit := range commits {
-		commitShas[i] = commit.Sha
-	}
+	commitShas := slices.Map(commits, func(commit *models.Commit) string {
+		return commit.Sha
+	})
 
 	// note that we're not filtering these as we do non-rebasing commits just because
 	// I suspect that will cause some damage
diff --git a/pkg/commands/loaders/commits_test.go b/pkg/commands/loaders/commits_test.go
index ff406abaf..6bb81c57d 100644
--- a/pkg/commands/loaders/commits_test.go
+++ b/pkg/commands/loaders/commits_test.go
@@ -11,24 +11,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func NewDummyCommitLoader() *CommitLoader {
-	cmn := utils.NewDummyCommon()
-
-	return &CommitLoader{
-		Common:               cmn,
-		cmd:                  nil,
-		getCurrentBranchName: func() (string, string, error) { return "master", "master", nil },
-		getRebaseMode:        func() (enums.RebaseMode, error) { return enums.REBASE_MODE_NONE, nil },
-		dotGitDir:            ".git",
-		readFile: func(filename string) ([]byte, error) {
-			return []byte(""), nil
-		},
-		walkFiles: func(root string, fn filepath.WalkFunc) error {
-			return nil
-		},
-	}
-}
-
 const commitsOutput = `0eea75e8c631fba6b58135697835d58ba4c18dbc|1640826609|Jesse Duffield| (HEAD -> better-tests)|b21997d6b4cbdf84b149|better typing for rebase mode
 b21997d6b4cbdf84b149d8e6a2c4d06a8e9ec164|1640824515|Jesse Duffield| (origin/better-tests)|e94e8fc5b6fab4cb755f|fix logging
 e94e8fc5b6fab4cb755f29f1bdb3ee5e001df35c|1640823749|Jesse Duffield||d8084cd558925eb7c9c3|refactor
diff --git a/pkg/commands/loaders/tags.go b/pkg/commands/loaders/tags.go
index 45b08a002..8e5063c34 100644
--- a/pkg/commands/loaders/tags.go
+++ b/pkg/commands/loaders/tags.go
@@ -1,8 +1,7 @@
 package loaders
 
 import (
-	"strings"
-
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
 	"github.com/jesseduffield/lazygit/pkg/common"
@@ -27,25 +26,18 @@ func NewTagLoader(
 func (self *TagLoader) GetTags() ([]*models.Tag, error) {
 	// get remote branches, sorted  by creation date (descending)
 	// see: https://git-scm.com/docs/git-tag#Documentation/git-tag.txt---sortltkeygt
-	remoteBranchesStr, err := self.cmd.New(`git tag --list --sort=-creatordate`).DontLog().RunWithOutput()
+	tagsOutput, err := self.cmd.New(`git tag --list --sort=-creatordate`).DontLog().RunWithOutput()
 	if err != nil {
 		return nil, err
 	}
 
-	content := utils.TrimTrailingNewline(remoteBranchesStr)
-	if content == "" {
-		return nil, nil
-	}
-
-	split := strings.Split(content, "\n")
+	split := utils.SplitLines(tagsOutput)
 
-	// first step is to get our remotes from go-git
-	tags := make([]*models.Tag, len(split))
-	for i, tagName := range split {
-		tags[i] = &models.Tag{
+	tags := slices.Map(split, func(tagName string) *models.Tag {
+		return &models.Tag{
 			Name: tagName,
 		}
-	}
+	})
 
 	return tags, nil
 }
diff --git a/pkg/commands/loaders/tags_test.go b/pkg/commands/loaders/tags_test.go
new file mode 100644
index 000000000..5394fa3a8
--- /dev/null
+++ b/pkg/commands/loaders/tags_test.go
@@ -0,0 +1,68 @@
+package loaders
+
+import (
+	"testing"
+
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
+	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+	"github.com/stretchr/testify/assert"
+)
+
+const tagsOutput = `v0.34
+v0.33
+v0.32.2
+v0.32.1
+v0.32
+testtag
+`
+
+func TestGetTags(t *testing.T) {
+	type scenario struct {
+		testName      string
+		runner        *oscommands.FakeCmdObjRunner
+		expectedTags  []*models.Tag
+		expectedError error
+	}
+
+	scenarios := []scenario{
+		{
+			testName: "should return no tags if there are none",
+			runner: oscommands.NewFakeRunner(t).
+				Expect(`git tag --list --sort=-creatordate`, "", nil),
+			expectedTags:  []*models.Tag{},
+			expectedError: nil,
+		},
+		{
+			testName: "should return tags if present",
+			runner: oscommands.NewFakeRunner(t).
+				Expect(`git tag --list --sort=-creatordate`, tagsOutput, nil),
+			expectedTags: []*models.Tag{
+				{Name: "v0.34"},
+				{Name: "v0.33"},
+				{Name: "v0.32.2"},
+				{Name: "v0.32.1"},
+				{Name: "v0.32"},
+				{Name: "testtag"},
+			},
+			expectedError: nil,
+		},
+	}
+
+	for _, scenario := range scenarios {
+		scenario := scenario
+		t.Run(scenario.testName, func(t *testing.T) {
+			loader := &TagLoader{
+				Common: utils.NewDummyCommon(),
+				cmd:    oscommands.NewDummyCmdObjBuilder(scenario.runner),
+			}
+
+			tags, err := loader.GetTags()
+
+			assert.Equal(t, scenario.expectedTags, tags)
+			assert.Equal(t, scenario.expectedError, err)
+
+			scenario.runner.CheckForMissingCalls()
+		})
+	}
+}
diff --git a/pkg/commands/oscommands/os.go b/pkg/commands/oscommands/os.go
index f3df3956f..b6f018af5 100644
--- a/pkg/commands/oscommands/os.go
+++ b/pkg/commands/oscommands/os.go
@@ -12,6 +12,7 @@ import (
 	"github.com/go-errors/errors"
 
 	"github.com/atotto/clipboard"
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/common"
 	"github.com/jesseduffield/lazygit/pkg/utils"
 )
@@ -173,15 +174,11 @@ func (c *OSCommand) FileExists(path string) (bool, error) {
 
 // PipeCommands runs a heap of commands and pipes their inputs/outputs together like A | B | C
 func (c *OSCommand) PipeCommands(commandStrings ...string) error {
-	cmds := make([]*exec.Cmd, len(commandStrings))
-	logCmdStr := ""
-	for i, str := range commandStrings {
-		if i > 0 {
-			logCmdStr += " | "
-		}
-		logCmdStr += str
-		cmds[i] = c.Cmd.New(str).GetCmd()
-	}
+	cmds := slices.Map(commandStrings, func(cmdString string) *exec.Cmd {
+		return c.Cmd.New(cmdString).GetCmd()
+	})
+
+	logCmdStr := strings.Join(commandStrings, " | ")
 	c.LogCommand(logCmdStr, true)
 
 	for i := 0; i < len(cmds)-1; i++ {
diff --git a/pkg/commands/patch/patch_manager.go b/pkg/commands/patch/patch_manager.go
index 1282356f8..4fb6507e6 100644
--- a/pkg/commands/patch/patch_manager.go
+++ b/pkg/commands/patch/patch_manager.go
@@ -4,6 +4,8 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/jesseduffield/generics/maps"
+	"github.com/jesseduffield/generics/slices"
 	"github.com/samber/lo"
 	"github.com/sirupsen/logrus"
 )
@@ -72,8 +74,9 @@ func (p *PatchManager) Start(from, to string, reverse bool, canRebase bool) {
 func (p *PatchManager) addFileWhole(info *fileInfo) {
 	info.mode = WHOLE
 	lineCount := len(strings.Split(info.diff, "\n"))
-	info.includedLineIndices = make([]int, lineCount)
 	// add every line index
+	// TODO: add tests and then use lo.Range to simplify
+	info.includedLineIndices = make([]int, lineCount)
 	for i := 0; i < lineCount; i++ {
 		info.includedLineIndices[i] = i
 	}
@@ -192,21 +195,15 @@ func (p *PatchManager) RenderPatchForFile(filename string, plain bool, reverse b
 
 func (p *PatchManager) renderEachFilePatch(plain bool) []string {
 	// sort files by name then iterate through and render each patch
-	filenames := make([]string, len(p.fileInfoMap))
-	index := 0
-	for filename := range p.fileInfoMap {
-		filenames[index] = filename
-		index++
-	}
+	filenames := maps.Keys(p.fileInfoMap)
 
 	sort.Strings(filenames)
-	output := []string{}
-	for _, filename := range filenames {
-		patch := p.RenderPatchForFile(filename, plain, false, true)
-		if patch != "" {
-			output = append(output, patch)
-		}
-	}
+	patches := slices.Map(filenames, func(filename string) string {
+		return p.RenderPatchForFile(filename, plain, false, true)
+	})
+	output := slices.Filter(patches, func(patch string) bool {
+		return patch != ""
+	})
 
 	return output
 }
diff --git a/pkg/commands/patch/patch_parser.go b/pkg/commands/patch/patch_parser.go
index 3810d8a29..097f01329 100644
--- a/pkg/commands/patch/patch_parser.go
+++ b/pkg/commands/patch/patch_parser.go
@@ -4,9 +4,9 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/jesseduffield/generics/slices"
 	"github.com/jesseduffield/lazygit/pkg/gui/style"
 	"github.com/jesseduffield/lazygit/pkg/theme"
-	"github.com/jesseduffield/lazygit/pkg/utils"
 	"github.com/samber/lo"
 	"github.com/sirupsen/logrus"
 )
@@ -184,16 +184,21 @@ func parsePatch(patch string) ([]int, []int, []*PatchLine) {
 
 // Render returns the coloured string of the diff with any selected lines highlighted
 func (p *PatchParser) Render(firstLineIndex int, lastLineIndex int, incLineIndices []int) string {
-	renderedLines := make([]string, len(p.PatchLines))
-	for index, patchLine := range p.PatchLines {
+	contentToDisplay := slices.Some(p.PatchLines, func(line *PatchLine) bool {
+		return line.Content != ""
+	})
+	if !contentToDisplay {
+		return ""
+	}
+
+	renderedLines := lo.Map(p.PatchLines, func(patchLine *PatchLine, index int) string {
 		selected := index >= firstLineIndex && index <= lastLineIndex
 		included := lo.Contains(incLineIndices, index)
-		renderedLines[index] = patchLine.render(selected, included)
-	}
+		return patchLine.render(selected, included)
+	})
+
 	result := strings.Join(renderedLines, "\n")
-	if strings.TrimSpace(utils.Decolorise(result)) == "" {
-		return ""
-	}
+
 	return result
 }
 
@@ -202,10 +207,9 @@ func (p *PatchParser) Render(firstLineIndex int, lastLineIndex int, incLineIndic
 func (p *PatchParser) PlainRenderLines(firstLineIndex, lastLineIndex int) string {
 	linesToCopy := p.PatchLines[firstLineIndex : lastLineIndex+1]
 
-	renderedLines := make([]string, len(linesToCopy))
-	for index, line := range linesToCopy {
-		renderedLines[index] = line.Content
-	}
+	renderedLines := slices.Map(linesToCopy, func(line *PatchLine) string {
+		return line.Content
+	})
 
 	return strings.Join(renderedLines, "\n")
 }