From bfb37de9eac70cb8b30c04708a554c1ad06e33ad Mon Sep 17 00:00:00 2001
From: Owen Rumney <owen@owenrumney.co.uk>
Date: Fri, 21 Jan 2022 16:36:20 +0000
Subject: [PATCH] handle single line new file patches

---
 commenter/commenter.go      | 18 ++++++++++++------
 commenter/commitFileInfo.go |  4 ++++
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/commenter/commenter.go b/commenter/commenter.go
index de57357..ac59c58 100644
--- a/commenter/commenter.go
+++ b/commenter/commenter.go
@@ -17,7 +17,7 @@ type Commenter struct {
 }
 
 var (
-	patchRegex     = regexp.MustCompile(`^@@.*\+(\d+),(\d+).+?@@`)
+	patchRegex     = regexp.MustCompile(`^@@.*[\+\-](\d+),(\d+).+?@@`)
 	commitRefRegex = regexp.MustCompile(".+ref=(.+)")
 )
 
@@ -156,7 +156,7 @@ func (c *Commenter) checkCommentRelevant(filename string, line int) bool {
 
 	for _, file := range c.files {
 		if relevant := func(file *commitFileInfo) bool {
-			if file.FileName == filename && !file.isBinary() {
+			if file.FileName == filename && !file.isResolvable() {
 				if line >= file.hunkStart && line <= file.hunkEnd {
 					return true
 				}
@@ -172,7 +172,7 @@ func (c *Commenter) checkCommentRelevant(filename string, line int) bool {
 func (c *Commenter) getFileInfo(file string, line int) (*commitFileInfo, error) {
 
 	for _, info := range c.files {
-		if info.FileName == file && !info.isBinary() {
+		if info.FileName == file && !info.isResolvable() {
 			if line >= info.hunkStart && line <= info.hunkEnd {
 				return info, nil
 			}
@@ -197,12 +197,18 @@ func getCommitInfo(file *github.CommitFile) (cfi *commitFileInfo, err error) {
 	var isBinary bool
 	patch := file.GetPatch()
 	if patch != "" {
-		groups := patchRegex.FindAllStringSubmatch(file.GetPatch(), -1)
+		groups := patchRegex.FindAllStringSubmatch(patch, -1)
 		if len(groups) < 1 {
 			return nil, fmt.Errorf("the patch details for [%s] could not be resolved", *file.Filename)
 		}
-		hunkStart, _ = strconv.Atoi(groups[0][1])
-		hunkEnd, _ = strconv.Atoi(groups[0][2])
+		hunkStart, err = strconv.Atoi(groups[0][1])
+		if err != nil {
+			hunkStart = -1
+		}
+		hunkEnd, err = strconv.Atoi(groups[0][2])
+		if err != nil {
+			hunkEnd = -1
+		}
 	}
 
 	shaGroups := commitRefRegex.FindAllStringSubmatch(file.GetContentsURL(), -1)
diff --git a/commenter/commitFileInfo.go b/commenter/commitFileInfo.go
index 39925e7..0ee08af 100644
--- a/commenter/commitFileInfo.go
+++ b/commenter/commitFileInfo.go
@@ -47,3 +47,7 @@ func (cfi commitFileInfo) calculatePosition(line int) *int {
 func (cfi commitFileInfo) isBinary() bool {
 	return cfi.likelyBinary
 }
+
+func (cfi commitFileInfo) isResolvable() bool {
+	return cfi.isBinary() && cfi.hunkStart != -1 && cfi.hunkEnd != -1
+}