Empty repos should not fail on pull (#513)

cmd/clone.go

@@ -852,9 +852,23 @@ func CloneAllRepos(git git.Gitter, cloneTargets []scm.Repo) {
 						// Retry checkout
 						errRetry := git.Checkout(repo)
 						if errRetry != nil {
-							e := fmt.Sprintf("Could not checkout out %s, branch may not exist or may not have any contents/commits, no changes made on: %s Error: %v", repo.CloneBranch, repo.URL, errRetry)
+							hasRemoteHeads, errHasRemoteHeads := git.HasRemoteHeads(repo)
-							cloneErrors = append(cloneErrors, e)
+							if errHasRemoteHeads != nil {
-							return
+								e := fmt.Sprintf("Could not checkout %s, branch may not exist or may not have any contents/commits, no changes made on: %s Errors: %v %v", repo.CloneBranch, repo.URL, errRetry, errHasRemoteHeads)
+								cloneErrors = append(cloneErrors, e)
+								return
+							}
+							if hasRemoteHeads {
+								// weird, should not happen, return original checkout error
+								e := fmt.Sprintf("Could not checkout %s, branch may not exist or may not have any contents/commits, no changes made on: %s Error: %v", repo.CloneBranch, repo.URL, errRetry)
+								cloneErrors = append(cloneErrors, e)
+								return
+							} else {
+								// this is _just_ an empty repository
+								e := fmt.Sprintf("Could not checkout %s due to repository being empty, no changes made on: %s", repo.CloneBranch, repo.URL)
+								cloneInfos = append(cloneInfos, e)
+								return
+							}
 						}
 					}
 
@@ -1032,24 +1046,29 @@ func CloneAllRepos(git git.Gitter, cloneTargets []scm.Repo) {
 		writeGhorgStats(date, allReposToCloneCount, cloneCount, pulledCount, cloneInfosCount, cloneErrorsCount, updateRemoteCount, newCommits, pruneCount, hasCollisions)
 	}
 
-	if os.Getenv("GHORG_EXIT_CODE_ON_CLONE_INFOS") != "0" && cloneInfosCount > 0 {
+	if os.Getenv("GHORG_DONT_EXIT_UNDER_TEST") != "true" {
-		exitCode, err := strconv.Atoi(os.Getenv("GHORG_EXIT_CODE_ON_CLONE_INFOS"))
+		if os.Getenv("GHORG_EXIT_CODE_ON_CLONE_INFOS") != "0" && cloneInfosCount > 0 {
-		if err != nil {
+			exitCode, err := strconv.Atoi(os.Getenv("GHORG_EXIT_CODE_ON_CLONE_INFOS"))
-			colorlog.PrintError("Could not convert GHORG_EXIT_CODE_ON_CLONE_INFOS from string to integer")
+			if err != nil {
-			os.Exit(1)
+				colorlog.PrintError("Could not convert GHORG_EXIT_CODE_ON_CLONE_INFOS from string to integer")
-		}
+				os.Exit(1)
+			}
 
-		os.Exit(exitCode)
+			os.Exit(exitCode)
+		}
 	}
 
-	if cloneErrorsCount > 0 {
+	if os.Getenv("GHORG_DONT_EXIT_UNDER_TEST") != "true" {
-		exitCode, err := strconv.Atoi(os.Getenv("GHORG_EXIT_CODE_ON_CLONE_ISSUES"))
+		if cloneErrorsCount > 0 {
-		if err != nil {
+			exitCode, err := strconv.Atoi(os.Getenv("GHORG_EXIT_CODE_ON_CLONE_ISSUES"))
-			colorlog.PrintError("Could not convert GHORG_EXIT_CODE_ON_CLONE_ISSUES from string to integer")
+			if err != nil {
-			os.Exit(1)
+				colorlog.PrintError("Could not convert GHORG_EXIT_CODE_ON_CLONE_ISSUES from string to integer")
+				os.Exit(1)
+			}
+			os.Exit(exitCode)
 		}
-
+	} else {
-		os.Exit(exitCode)
+		cloneErrorsCount = 0
 	}
 
 }

cmd/clone_test.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"log"
 	"os"
 	"reflect"
@@ -13,6 +14,7 @@ import (
 func TestShouldLowerRegularString(t *testing.T) {
 
 	upperName := "RepoName"
+	defer setOutputDirName([]string{""})
 	setOutputDirName([]string{upperName})
 
 	if outputDirName != "reponame" {
@@ -23,6 +25,7 @@ func TestShouldLowerRegularString(t *testing.T) {
 func TestShouldNotChangeLowerCasedRegularString(t *testing.T) {
 
 	lowerName := "repo_name"
+	defer setOutputDirName([]string{""})
 	setOutputDirName([]string{lowerName})
 
 	if outputDirName != "repo_name" {
@@ -34,6 +37,7 @@ func TestReplaceDashWithUnderscore(t *testing.T) {
 
 	want := "repo-name"
 	lowerName := "repo-name"
+	defer setOutputDirName([]string{""})
 	setOutputDirName([]string{lowerName})
 
 	if outputDirName != want {
@@ -44,6 +48,7 @@ func TestReplaceDashWithUnderscore(t *testing.T) {
 func TestShouldNotChangeNonLettersString(t *testing.T) {
 
 	numberName := "1234567_8"
+	defer setOutputDirName([]string{""})
 	setOutputDirName([]string{numberName})
 
 	if outputDirName != "1234567_8" {
@@ -57,6 +62,13 @@ func NewMockGit() MockGitClient {
 	return MockGitClient{}
 }
 
+func (g MockGitClient) HasRemoteHeads(repo scm.Repo) (bool, error) {
+	if repo.Name == "testRepoEmpty" {
+		return false, nil
+	}
+	return true, nil
+}
+
 func (g MockGitClient) Clone(repo scm.Repo) error {
 	_, err := os.MkdirTemp(os.Getenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO"), repo.Name)
 	if err != nil {
@@ -74,6 +86,9 @@ func (g MockGitClient) SetOriginWithCredentials(repo scm.Repo) error {
 }
 
 func (g MockGitClient) Checkout(repo scm.Repo) error {
+	if repo.Name == "testRepoEmpty" {
+		return errors.New("Cannot checkout any specific branch in an empty repository")
+	}
 	return nil
 }
 
@@ -144,6 +159,49 @@ func TestInitialClone(t *testing.T) {
 	}
 }
 
+func TestCloneEmptyRepo(t *testing.T) {
+	defer UnsetEnv("GHORG_")()
+	dir, err := os.MkdirTemp("", "ghorg_test_empty_repo")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	os.Setenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO", dir)
+	setOuputDirAbsolutePath()
+
+	os.Setenv("GHORG_DONT_EXIT_UNDER_TEST", "true")
+
+	// simulate a previous clone of empty git repository
+	repoErr := os.Mkdir(outputDirAbsolutePath+"/"+"testRepoEmpty", 0o700)
+	if repoErr != nil {
+		log.Fatal(repoErr)
+	}
+	defer os.RemoveAll(outputDirAbsolutePath + "/" + "testRepoEmpty")
+
+	os.Setenv("GHORG_CONCURRENCY", "1")
+	var testRepos = []scm.Repo{
+		{
+			Name:        "testRepoEmpty",
+			URL:         "git@github.com:org/testRepoEmpty.git",
+			CloneBranch: "main",
+		},
+	}
+
+	mockGit := NewMockGit()
+	CloneAllRepos(mockGit, testRepos)
+	gotInfos := len(cloneInfos)
+	expectedInfos := 1
+	if gotInfos != expectedInfos {
+		t.Fatalf("Wrong number of cloneInfos, expected: %v, got: %v", expectedInfos, gotInfos)
+	}
+	gotInfo := cloneInfos[0]
+	expected := "Could not checkout main due to repository being empty, no changes made on: git@github.com:org/testRepoEmpty.git"
+	if gotInfo != expected {
+		t.Errorf("Wrong cloneInfo, expected: %v, got: %v", expected, gotInfo)
+	}
+}
+
 func TestMatchPrefix(t *testing.T) {
 	defer UnsetEnv("GHORG_")()
 	dir, err := os.MkdirTemp("", "ghorg_test_match_prefix")
@@ -154,6 +212,8 @@ func TestMatchPrefix(t *testing.T) {
 	os.Setenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO", dir)
 	os.Setenv("GHORG_CONCURRENCY", "1")
 	os.Setenv("GHORG_MATCH_PREFIX", "test")
+	os.Setenv("GHORG_DONT_EXIT_UNDER_TEST", "true")
+
 	var testRepos = []scm.Repo{
 		{
 			Name: "testRepoOne",
@@ -191,6 +251,8 @@ func TestExcludeMatchPrefix(t *testing.T) {
 	os.Setenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO", dir)
 	os.Setenv("GHORG_CONCURRENCY", "1")
 	os.Setenv("GHORG_EXCLUDE_MATCH_PREFIX", "test")
+	os.Setenv("GHORG_DONT_EXIT_UNDER_TEST", "true")
+
 	var testRepos = []scm.Repo{
 		{
 			Name: "testRepoOne",
@@ -228,6 +290,8 @@ func TestMatchRegex(t *testing.T) {
 	os.Setenv("GHORG_ABSOLUTE_PATH_TO_CLONE_TO", dir)
 	os.Setenv("GHORG_CONCURRENCY", "1")
 	os.Setenv("GHORG_MATCH_REGEX", "^test-")
+	os.Setenv("GHORG_DONT_EXIT_UNDER_TEST", "true")
+
 	var testRepos = []scm.Repo{
 		{
 			Name: "test-RepoOne",
@@ -267,6 +331,8 @@ func TestExcludeMatchRegex(t *testing.T) {
 	os.Setenv("GHORG_CONCURRENCY", "1")
 	os.Setenv("GHORG_OUTPUT_DIR", testDescriptor)
 	os.Setenv("GHORG_EXCLUDE_MATCH_REGEX", "^test-")
+	os.Setenv("GHORG_DONT_EXIT_UNDER_TEST", "true")
+
 	var testRepos = []scm.Repo{
 		{
 			Name: "test-RepoOne",

git/git.go

@@ -1,6 +1,7 @@
 package git
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"os/exec"
@@ -26,6 +27,7 @@ type Gitter interface {
 	FetchAll(scm.Repo) error
 	FetchCloneBranch(scm.Repo) error
 	RepoCommitCount(scm.Repo) (int, error)
+	HasRemoteHeads(scm.Repo) (bool, error)
 }
 
 type GitClient struct{}
@@ -51,6 +53,35 @@ func printDebugCmd(cmd *exec.Cmd, repo scm.Repo) error {
 	return err
 }
 
+func (g GitClient) HasRemoteHeads(repo scm.Repo) (bool, error) {
+	cmd := exec.Command("git", "ls-remote", "--heads", "--quiet", "--exit-code")
+
+	err := cmd.Run()
+	if err == nil {
+		// successfully listed the remote heads
+		return true, nil
+	}
+
+	var exitError *exec.ExitError
+	if !errors.As(err, &exitError) {
+		// error, but no exit code, return err
+		return false, err
+	}
+
+	exitCode := exitError.ExitCode()
+	if exitCode == 0 {
+		// ls-remote did successfully list the remote heads
+		return true, nil
+	} else if exitCode == 2 {
+		// repository is empty
+		return false, nil
+	} else {
+		// another exit code, simply return err
+		return false, err
+	}
+
+}
+
 func (g GitClient) Clone(repo scm.Repo) error {
 	args := []string{"clone", repo.CloneURL, repo.HostPath}