Use go:generate for generating cheatsheets

This has several benefits:
- it's less code
- we're using the same mechanism to generate all our auto-generated files, so if
  someone wants to add a new one, it's clear which pattern to follow
- we can re-generate all generated files with a single command
  ("go generate ./...", or "make generate")
- we only need a single check on CI to check that all files are up to date (see
  previous commit)

pkg/cheatsheet/check.go

@@ -1,77 +0,0 @@
-package cheatsheet
-
-import (
-	"fmt"
-	"io/fs"
-	"log"
-	"os"
-	"path/filepath"
-	"regexp"
-
-	"github.com/pmezard/go-difflib/difflib"
-)
-
-func Check() {
-	dir := GetKeybindingsDir()
-	tmpDir := filepath.Join(os.TempDir(), "lazygit_cheatsheet")
-	err := os.RemoveAll(tmpDir)
-	if err != nil {
-		log.Fatalf("Error occurred while checking if cheatsheets are up to date: %v", err)
-	}
-	err = os.Mkdir(tmpDir, 0o700)
-	if err != nil {
-		log.Fatalf("Error occurred while checking if cheatsheets are up to date: %v", err)
-	}
-
-	generateAtDir(tmpDir)
-	defer os.RemoveAll(tmpDir)
-
-	actualContent := obtainContent(dir)
-	expectedContent := obtainContent(tmpDir)
-
-	if expectedContent == "" {
-		log.Fatal("empty expected content")
-	}
-
-	if actualContent != expectedContent {
-		err := difflib.WriteUnifiedDiff(os.Stdout, difflib.UnifiedDiff{
-			A:        difflib.SplitLines(expectedContent),
-			B:        difflib.SplitLines(actualContent),
-			FromFile: "Expected",
-			FromDate: "",
-			ToFile:   "Actual",
-			ToDate:   "",
-			Context:  1,
-		})
-		if err != nil {
-			log.Fatalf("Error occurred while checking if cheatsheets are up to date: %v", err)
-		}
-		fmt.Printf("\nCheatsheets are out of date. Please run `%s` at the project root and commit the changes. If you run the script and no keybindings files are updated as a result, try rebasing onto master and trying again.\n", CommandToRun())
-		os.Exit(1)
-	}
-
-	fmt.Println("\nCheatsheets are up to date")
-}
-
-func obtainContent(dir string) string {
-	re := regexp.MustCompile(`Keybindings_\w+\.md$`)
-
-	content := ""
-	err := filepath.WalkDir(dir, func(path string, d fs.DirEntry, err error) error {
-		if re.MatchString(path) {
-			bytes, err := os.ReadFile(path)
-			if err != nil {
-				log.Fatalf("Error occurred while checking if cheatsheets are up to date: %v", err)
-			}
-			content += fmt.Sprintf("\n%s\n\n", filepath.Base(path))
-			content += string(bytes)
-		}
-
-		return nil
-	})
-	if err != nil {
-		log.Fatalf("Error occurred while checking if cheatsheets are up to date: %v", err)
-	}
-
-	return content
-}

pkg/cheatsheet/generate.go

@@ -1,10 +1,12 @@
-// This "script" generates a file called Keybindings_{{.LANG}}.md
-// in current working directory.
+//go:generate go run generator.go
+
+// This "script" generates files called Keybindings_{{.LANG}}.md
+// in the docs/keybindings directory.
 //
-// The content of this generated file is a keybindings cheatsheet.
+// The content of these generated files is a keybindings cheatsheet.
 //
-// To generate cheatsheet in english run:
-//   go run scripts/generate_cheatsheet.go
+// To generate the cheatsheets, run:
+//   go generate pkg/cheatsheet/generate.go
 
 package cheatsheet
 
@@ -42,7 +44,7 @@ type headerWithBindings struct {
 }
 
 func CommandToRun() string {
-	return "go run scripts/cheatsheet/main.go generate"
+	return "go generate ./..."
 }
 
 func GetKeybindingsDir() string {

pkg/cheatsheet/generator.go

@@ -0,0 +1,14 @@
+//go:build ignore
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/jesseduffield/lazygit/pkg/cheatsheet"
+)
+
+func main() {
+	fmt.Printf("Generating cheatsheets in %s...\n", cheatsheet.GetKeybindingsDir())
+	cheatsheet.Generate()
+}