From 420991cf4fd9854190623960fe46b19fc75f6d48 Mon Sep 17 00:00:00 2001
From: Craig Gumbley <craiggumbley@gmail.com>
Date: Fri, 15 Apr 2022 18:24:05 +0100
Subject: [PATCH] Implement better errors

This commit adds the foundational code for better error handling. It
largely draws from the code in gh-cli that allows for better error
customization.

It addresses issues #1 and #2.
---
 cmd/root.go                               | 21 +++++++++++++++++----
 internal/pkg/changelog/changelog.go       | 17 +++++++++++------
 internal/pkg/githubclient/githubclient.go |  4 ++++
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/cmd/root.go b/cmd/root.go
index 350e902..d6c62cc 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"time"
@@ -13,13 +14,16 @@ import (
 )
 
 var version = "dev"
+var ErrSilent = errors.New("ErrSilent")
 
 // RootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:     "changelog [args]",
-	Short:   "Create a changelog that adheres to the [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) format",
-	Long:    "Create a changelog that adheres to the [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) format",
-	Version: version,
+	Use:           "changelog",
+	Short:         "Create a changelog that adheres to the [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) format",
+	Long:          "Create a changelog that adheres to the [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) format",
+	Version:       version,
+	SilenceUsage:  true,
+	SilenceErrors: true,
 	RunE: func(command *cobra.Command, args []string) error {
 
 		s := spinner.New(spinner.CharSets[11], 100*time.Millisecond)
@@ -43,10 +47,19 @@ func init() {
 		fmt.Println(err)
 		os.Exit(1)
 	}
+
+	rootCmd.SetFlagErrorFunc(func(cmd *cobra.Command, err error) error {
+		cmd.Println(err)
+		cmd.Println(cmd.UsageString())
+		return ErrSilent
+	})
 }
 
 func Execute() int {
 	if err := rootCmd.Execute(); err != nil {
+		if err != ErrSilent {
+			fmt.Fprintln(os.Stderr, err)
+		}
 		return 1
 	}
 	return 0
diff --git a/internal/pkg/changelog/changelog.go b/internal/pkg/changelog/changelog.go
index 2278395..890c53e 100644
--- a/internal/pkg/changelog/changelog.go
+++ b/internal/pkg/changelog/changelog.go
@@ -15,7 +15,7 @@ import (
 func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 	client, err := githubclient.NewGitHubClient()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("❌ %s", err)
 	}
 
 	changeLog := NewChangeLogProperties(client.RepoContext.Owner, client.RepoContext.Repo)
@@ -25,7 +25,7 @@ func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 
 	tags, err := client.GetTags()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("❌ could not get tags: %v", err)
 	}
 
 	// Sort by date, this is mad slow but you can't get at the date
@@ -46,7 +46,7 @@ func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 		spinner.Suffix = fmt.Sprintf(" Processing tags: 🏷️  %s", tag.GetName())
 		currentCommit, err := client.GetCommit(tag.GetCommit().GetSHA())
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("❌ could not get commit for tag '%s': %v", tag.GetName(), err)
 		}
 
 		var nextCommit *github.Commit
@@ -57,7 +57,7 @@ func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 		}
 
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("❌ could not get next commit: %v", err)
 		}
 
 		pullRequests, err := client.GetPullRequestsBetweenDates(
@@ -65,7 +65,12 @@ func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 			currentCommit.GetCommitter().GetDate(),
 		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf(
+				"❌ could not get pull requests for range '%s - %s': %v",
+				nextCommit.GetCommitter().GetDate(),
+				currentCommit.GetCommitter().GetDate(),
+				err,
+			)
 		}
 
 		typeMap, err := processPullRequests(
@@ -75,7 +80,7 @@ func MakeFullChangelog(spinner *spinner.Spinner) (*ChangeLogProperties, error) {
 			viper.GetStringSlice("excludedLabels"),
 		)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("❌ could not process pull requests: %v", err)
 		}
 
 		changeLog.Tags = append(changeLog.Tags, *typeMap)
diff --git a/internal/pkg/githubclient/githubclient.go b/internal/pkg/githubclient/githubclient.go
index 48e8a28..409ec22 100644
--- a/internal/pkg/githubclient/githubclient.go
+++ b/internal/pkg/githubclient/githubclient.go
@@ -34,6 +34,10 @@ func NewGitHubClient() (*GitHubClient, error) {
 
 	currentRepository, err := gh.CurrentRepository()
 	if err != nil {
+		if strings.Contains(err.Error(), "not a git repository (or any of the parent directories)") {
+			return nil, fmt.Errorf("the current directory is not a git repository")
+		}
+
 		return nil, err
 	}