fix: issue with GH App credential not writing if lines already exist (#…

…3679)

* Fix issue with GH App credential not writing if lines already exist

* Fix lint issue of unused variable.

---------

Co-authored-by: PePe Amengual <[email protected]>
Co-authored-by: Dylan Page <[email protected]>

server/events/vcs/git_cred_writer.go

@@ -38,11 +38,23 @@ func WriteGitCreds(gitUser string, gitToken string, gitHostname string, home str
 		}
 
 		if ghAccessToken {
-			// Need to replace the line.
-			if err := fileLineReplace(config, gitUser, gitHostname, credsFile); err != nil {
-				return errors.Wrap(err, "replacing git credentials line for github app")
+			hasGHToken, err := fileHasGHToken(gitUser, gitHostname, credsFile)
+			if err != nil {
+				return err
+			}
+			if hasGHToken {
+				// Need to replace the line.
+				if err := fileLineReplace(config, gitUser, gitHostname, credsFile); err != nil {
+					return errors.Wrap(err, "replacing git credentials line for github app")
+				}
+				logger.Info("updated git app credentials in %s", credsFile)
+			} else {
+				if err := fileAppend(config, credsFile); err != nil {
+					return err
+				}
+				logger.Info("wrote git credentials to %s", credsFile)
 			}
-			logger.Info("updated git app credentials in %s", credsFile)
+
 		} else {
 			// Otherwise we need to append the line.
 			if err := fileAppend(config, credsFile); err != nil {
@@ -113,3 +125,17 @@ func fileLineReplace(line, user, host, filename string) error {
 
 	return os.WriteFile(filename, []byte(toWrite), 0600)
 }
+
+func fileHasGHToken(user, host, filename string) (bool, error) {
+	currContents, err := os.ReadFile(filename) // nolint: gosec
+	if err != nil {
+		return false, err
+	}
+	prevLines := strings.Split(string(currContents), "\n")
+	for _, l := range prevLines {
+		if strings.HasPrefix(l, "https://"+user) && strings.HasSuffix(l, host) {
+			return true, nil
+		}
+	}
+	return false, nil
+}

server/events/vcs/git_cred_writer_test.go

@@ -86,6 +86,25 @@ func TestWriteGitCreds_ReplaceApp(t *testing.T) {
 	Equals(t, expContets, string(actContents))
 }
 
+// Test that the github app credential gets added even if there are other credentials.
+func TestWriteGitCreds_AppendAppWhenFileNotEmpty(t *testing.T) {
+	logger := logging.NewNoopLogger(t)
+	tmp := t.TempDir()
+	t.Setenv("HOME", tmp)
+
+	credsFile := filepath.Join(tmp, ".git-credentials")
+	contents := "line1\nhttps://user:[email protected]\nline2"
+	err := os.WriteFile(credsFile, []byte(contents), 0600)
+	Ok(t, err)
+
+	err = vcs.WriteGitCreds("x-access-token", "token", "github.com", tmp, logger, true)
+	Ok(t, err)
+	expContets := "line1\nhttps://user:[email protected]\nline2\nhttps://x-access-token:[email protected]"
+	actContents, err := os.ReadFile(filepath.Join(tmp, ".git-credentials"))
+	Ok(t, err)
+	Equals(t, expContets, string(actContents))
+}
+
 // Test that the github app credentials get updated when cred file is empty.
 func TestWriteGitCreds_AppendApp(t *testing.T) {
 	logger := logging.NewNoopLogger(t)