From 2b4f8554b207868fc4e60083c69dc48387fceecf Mon Sep 17 00:00:00 2001
From: ypjama <3822534+ypjama@users.noreply.github.com>
Date: Thu, 19 Oct 2023 22:06:20 +0300
Subject: [PATCH] Add flag for overriding default changelog file

---
 README.md                             |  2 +
 changes/generate.yml                  |  2 +
 internal/pkg/conflictless/check.go    |  4 +-
 internal/pkg/conflictless/cli.go      | 12 +++++-
 internal/pkg/conflictless/cli_test.go | 56 +++++++++++++++++++++++++++
 internal/pkg/conflictless/config.go   | 37 ++++++++++++++++--
 internal/pkg/conflictless/generate.go |  6 +--
 internal/pkg/conflictless/help.go     |  3 +-
 internal/pkg/conflictless/usage.go    |  8 +++-
 9 files changed, 120 insertions(+), 10 deletions(-)
 create mode 100644 changes/generate.yml

diff --git a/README.md b/README.md
index 7b9c99a..c29b35e 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,8 @@ The flags are:
 
         -b, --bump
                 Bump version patch/minor/major (default: minor)
+        -c, --changelog
+                Changelog file (default: CHANGELOG.md)
         -d, --dir
                 Directory where to look for change-files (default: changes)
         -s, --skip-version-links
diff --git a/changes/generate.yml b/changes/generate.yml
new file mode 100644
index 0000000..5593527
--- /dev/null
+++ b/changes/generate.yml
@@ -0,0 +1,2 @@
+added:
+  - 'New flag for "generate" command: "-c, --changelog" for overriding the default changelog file name'
diff --git a/internal/pkg/conflictless/check.go b/internal/pkg/conflictless/check.go
index 427ca83..b7a52cb 100644
--- a/internal/pkg/conflictless/check.go
+++ b/internal/pkg/conflictless/check.go
@@ -2,7 +2,9 @@ package conflictless
 
 // Check checks the validity of the change files.
 func Check(cfg *Config) {
-	combined, err := scanDir(*cfg.Flags.Directory)
+	cfg.SetCheckConfigsFromFlags()
+
+	combined, err := scanDir(cfg.Directory)
 	if err != nil {
 		PrintErrorAndExit(err.Error(), func() {})
 	}
diff --git a/internal/pkg/conflictless/cli.go b/internal/pkg/conflictless/cli.go
index 2479e19..2f42ff6 100644
--- a/internal/pkg/conflictless/cli.go
+++ b/internal/pkg/conflictless/cli.go
@@ -24,6 +24,7 @@ func CLI() {
 	cfg := Config{
 		Flags: FlagCollection{
 			Bump:             new(string),
+			ChangelogFile:    new(string),
 			Command:          "",
 			Directory:        new(string),
 			SkipVersionLinks: false,
@@ -32,6 +33,7 @@ func CLI() {
 		ChangelogFile:        "CHANGELOG.md",
 		RepositoryConfigFile: ".git/config",
 		Changelog:            nil,
+		Directory:            "changes",
 	}
 	parseCLIFlags(&cfg)
 
@@ -45,7 +47,7 @@ func CLI() {
 	case commandGen:
 		Generate(&cfg)
 	case commandHelp:
-		help()
+		Help()
 	default:
 		PrintErrorAndExit(fmt.Sprintf("invalid command: '%s'", cfg.Flags.Command), usageOnError)
 	}
@@ -85,6 +87,7 @@ func parseCLIFlags(cfg *Config) {
 		cmd.Usage = usageGenerateOnError
 
 		defineBumpFlags(cfg, cmd)
+		defineChangeLogFlags(cfg, cmd)
 		defineDirFlags(cfg, cmd)
 		defineSkipFlags(cfg, cmd)
 	case commandCheck:
@@ -102,6 +105,13 @@ func parseCLIFlags(cfg *Config) {
 	}
 }
 
+func defineChangeLogFlags(cfg *Config, fs *flag.FlagSet) {
+	defaultChangelogFile := "CHANGELOG.md"
+
+	fs.StringVar(cfg.Flags.ChangelogFile, "changelog", defaultChangelogFile, "")
+	fs.StringVar(cfg.Flags.ChangelogFile, "c", defaultChangelogFile, "")
+}
+
 func defineBumpFlags(cfg *Config, fs *flag.FlagSet) {
 	defaultBumpStr := "minor"
 
diff --git a/internal/pkg/conflictless/cli_test.go b/internal/pkg/conflictless/cli_test.go
index 26c6923..f4b877f 100644
--- a/internal/pkg/conflictless/cli_test.go
+++ b/internal/pkg/conflictless/cli_test.go
@@ -157,3 +157,59 @@ func TestCLIHelp(t *testing.T) {
 		})
 	}
 }
+
+func TestCLIGenerateWithInvalidFlags(t *testing.T) {
+	t.Parallel()
+
+	if os.Getenv("TEST_CLI_GENERATE_INVALID_FLAGS") != "" {
+		conflictless.CLI()
+
+		return
+	}
+
+	stdoutFile := createTempFile(t, os.TempDir(), "test-cli-generate-with-invalid-flags-stdout")
+	defer os.Remove(stdoutFile.Name())
+
+	stderrFile := createTempFile(t, os.TempDir(), "test-cli-generate-with-invalid-flags-stderr")
+	defer os.Remove(stderrFile.Name())
+
+	//nolint:gosec // this is a test package so G204 doesn't really matter here.
+	cmd := exec.Command(
+		os.Args[0],
+		"-test.run=^TestCLIGenerateWithInvalidFlags$",
+		"generate",
+		"--dir",
+		"rhymenocerous",
+		"--changelog",
+		"HIPPOPOTAMUS.md",
+		"--bump",
+		"steve",
+	)
+
+	cmd.Stdout = stdoutFile
+	cmd.Stderr = stderrFile
+
+	cmd.Env = append(os.Environ(), "TEST_CLI_GENERATE_INVALID_FLAGS=1")
+	err := cmd.Run()
+
+	assert.Error(t, err)
+
+	assert.IsType(t, new(exec.ExitError), err)
+
+	exitErr := new(*exec.ExitError)
+	errors.As(err, exitErr)
+
+	expectedCode := 2
+	exitCode := (*exitErr).ExitCode()
+
+	assert.Equal(t, expectedCode, exitCode, "process exited with %d, want exit status %d", expectedCode, exitCode)
+
+	stdoutData, err := os.ReadFile(stdoutFile.Name())
+	assert.NoError(t, err)
+
+	stderrData, err := os.ReadFile(stderrFile.Name())
+	assert.NoError(t, err)
+
+	assert.Empty(t, string(stdoutData))
+	assert.NotEmpty(t, string(stderrData))
+}
diff --git a/internal/pkg/conflictless/config.go b/internal/pkg/conflictless/config.go
index f6b60d0..9e48469 100644
--- a/internal/pkg/conflictless/config.go
+++ b/internal/pkg/conflictless/config.go
@@ -5,8 +5,9 @@ import "fmt"
 // FlagCollection is a collection of flags.
 type FlagCollection struct {
 	Bump             *string
-	Directory        *string
+	ChangelogFile    *string
 	Command          string
+	Directory        *string
 	SkipVersionLinks bool
 }
 
@@ -16,12 +17,42 @@ type Config struct {
 	Bump                 Bump
 	ChangelogFile        string
 	RepositoryConfigFile string
+	Directory            string
 	Changelog            *Changelog
 }
 
+func (cfg *Config) SetGenerateConfigsFromFlags() error {
+	cfg.SetChangelogFileFromFlags()
+	cfg.SetDirectoryFromFlags()
+
+	return cfg.SetBumpFromFlags()
+}
+
+func (cfg *Config) SetCheckConfigsFromFlags() {
+	cfg.SetDirectoryFromFlags()
+}
+
+func (cfg *Config) SetDirectoryFromFlags() {
+	if cfg.Flags.Directory != nil {
+		cfg.Directory = *cfg.Flags.Directory
+	}
+}
+
+func (cfg *Config) SetChangelogFileFromFlags() {
+	if cfg.Flags.ChangelogFile != nil {
+		cfg.ChangelogFile = *cfg.Flags.ChangelogFile
+	}
+}
+
 // SetBumpFromFlags sets the bump type by parsing the flag string.
 func (cfg *Config) SetBumpFromFlags() error {
-	switch *cfg.Flags.Bump {
+	bumpFlag := ""
+
+	if cfg.Flags.Bump != nil {
+		bumpFlag = *cfg.Flags.Bump
+	}
+
+	switch bumpFlag {
 	case "patch":
 		cfg.Bump = BumpPatch
 	case "minor":
@@ -29,7 +60,7 @@ func (cfg *Config) SetBumpFromFlags() error {
 	case "major":
 		cfg.Bump = BumpMajor
 	default:
-		return fmt.Errorf("%w: %s", ErrInvalidBumpFlag, *cfg.Flags.Bump)
+		return fmt.Errorf("%w: %s", ErrInvalidBumpFlag, bumpFlag)
 	}
 
 	return nil
diff --git a/internal/pkg/conflictless/generate.go b/internal/pkg/conflictless/generate.go
index 372efa3..e6dda7b 100644
--- a/internal/pkg/conflictless/generate.go
+++ b/internal/pkg/conflictless/generate.go
@@ -10,7 +10,7 @@ import (
 
 // Generate generates a new version section in the changelog.
 func Generate(cfg *Config) {
-	err := cfg.SetBumpFromFlags()
+	err := cfg.SetGenerateConfigsFromFlags()
 	if err != nil {
 		PrintErrorAndExit(err.Error(), usageGenerateOnError)
 	}
@@ -20,7 +20,7 @@ func Generate(cfg *Config) {
 		PrintErrorAndExit(err.Error(), func() {})
 	}
 
-	combined, err := scanDir(*cfg.Flags.Directory)
+	combined, err := scanDir(cfg.Directory)
 	if err != nil {
 		PrintErrorAndExit(err.Error(), func() {})
 	}
@@ -39,7 +39,7 @@ func Generate(cfg *Config) {
 		PrintErrorAndExit(err.Error(), func() {})
 	}
 
-	err = removeChangeFiles(*cfg.Flags.Directory)
+	err = removeChangeFiles(cfg.Directory)
 	if err != nil {
 		PrintErrorAndExit(err.Error(), func() {})
 	}
diff --git a/internal/pkg/conflictless/help.go b/internal/pkg/conflictless/help.go
index 269591b..864ed43 100644
--- a/internal/pkg/conflictless/help.go
+++ b/internal/pkg/conflictless/help.go
@@ -5,7 +5,8 @@ import (
 	"os"
 )
 
-func help() {
+// Help prints the help message and exits.
+func Help() {
 	var topic string
 
 	args := argsWithoutTestFlags()
diff --git a/internal/pkg/conflictless/usage.go b/internal/pkg/conflictless/usage.go
index 4ed81d4..cfb29ec 100644
--- a/internal/pkg/conflictless/usage.go
+++ b/internal/pkg/conflictless/usage.go
@@ -8,7 +8,11 @@ import (
 const (
 	flagIndentation            = "\t"
 	flagDescriptionIndentation = "\t\t"
-	flagDescriptionDir         = flagIndentation +
+	flagDescriptionChangelog   = flagIndentation +
+		"-c, --changelog\n" +
+		flagDescriptionIndentation +
+		"Changelog file (default: CHANGELOG.md)"
+	flagDescriptionDir = flagIndentation +
 		"-d, --dir\n" +
 		flagDescriptionIndentation +
 		"Directory where to look for change-files (default: changes)"
@@ -44,8 +48,10 @@ The flags are:
 %s
 %s
 %s
+%s
 `,
 		flagDescriptionBump,
+		flagDescriptionChangelog,
 		flagDescriptionDir,
 		flagDescriptionSkipVersionLinks,
 	)