improve github pullrequest title

internal/change.go

@@ -24,6 +24,8 @@ type Change struct {
 
 type Changes []Change
 
+const gitHubMaxPullRequestTitleLength = 256
+
 func (c Change) Identifier() string {
 	return c.File + "#" + c.Trace.ToString() + "#" + c.NewValue
 }
@@ -51,6 +53,18 @@ func (c Change) Message() string {
 	return fmt.Sprintf("Update %s:%s from %s to %s", c.File, c.Trace.ToString(), c.OldValue, c.NewValue)
 }
 
+func (cs Changes) Title() string {
+	updates := []string{}
+	for _, change := range cs {
+		updates = append(updates, fmt.Sprintf("%s:%s", change.ResourceName, change.NewVersion))
+	}
+	result := fmt.Sprintf("Update %s", strings.Join(updates, ", "))
+	if len(result) > gitHubMaxPullRequestTitleLength {
+		return result[0:gitHubMaxPullRequestTitleLength]
+	}
+	return result
+}
+
 func (cs Changes) Message() string {
 	lines := []string{}
 	if len(cs) > 1 {

internal/change_test.go

@@ -6,30 +6,39 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var c1 = Change{
+	RegistryName: "my-registry",
+	ResourceName: "my-resource",
+	OldVersion:   "1.0.0",
+	NewVersion:   "2.0.0",
+	OldValue:     "my-image:1.0.0",
+	NewValue:     "my-image:2.0.0",
+	File:         "folder/file.yaml",
+	Trace:        []interface{}{"spec", 0, "image"},
+}
+
+var c2 = Change{
+	RegistryName: "my-registry2",
+	ResourceName: "my-resource2",
+	OldVersion:   "3.0.0",
+	NewVersion:   "4.0.0",
+	OldValue:     "my-image2:3.0.0",
+	NewValue:     "my-image2:4.0.0",
+	File:         "folder/file2.yaml",
+	Trace:        []interface{}{"spec", 0, "image2"},
+}
+
 func TestChangeIdentifier(t *testing.T) {
-	c := Change{
-		RegistryName: "my-registry",
-		ResourceName: "my-resource",
-		OldVersion:   "1.0.0",
-		NewVersion:   "2.0.0",
-		OldValue:     "my-image:1.0.0",
-		NewValue:     "my-image:2.0.0",
-		File:         "folder/file.yaml",
-		Trace:        []interface{}{"spec", 0, "image"},
-	}
-	assert.Equal(t, "folder/file.yaml#spec.0.image#my-image:2.0.0", c.Identifier())
+	assert.Equal(t, "folder/file.yaml#spec.0.image#my-image:2.0.0", c1.Identifier())
+	assert.Equal(t, "folder/file2.yaml#spec.0.image2#my-image2:4.0.0", c2.Identifier())
+}
+
+func TestChangesTitle(t *testing.T) {
+	assert.Equal(t, "Update my-resource:2.0.0", Changes{c1}.Title())
+	assert.Equal(t, "Update my-resource:2.0.0, my-resource2:4.0.0", Changes{c1, c2}.Title())
 }
 
 func TestChangesBranch(t *testing.T) {
-	cs := Changes{Change{
-		RegistryName: "my-registry",
-		ResourceName: "my-resource",
-		OldVersion:   "1.0.0",
-		NewVersion:   "2.0.0",
-		OldValue:     "my-image:1.0.0",
-		NewValue:     "my-image:2.0.0",
-		File:         "folder/file.yaml",
-		Trace:        []interface{}{"spec", 0, "image"},
-	}}
-	assert.Equal(t, "git-ops-update/b192fbd55a666b30", cs.Branch("git-ops-update"))
+	assert.Equal(t, "git-ops-update/b192fbd55a666b30", Changes{c1}.Branch("git-ops-update"))
+	assert.Equal(t, "git-ops-update/925d44a4f1703462", Changes{c1, c2}.Branch("git-ops-update"))
 }

internal/git_github.go

@@ -99,9 +99,9 @@ func (p GitHubGitProvider) Request(dir string, changes Changes, callbacks ...fun
 	ts := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: p.AccessToken})
 	tc := oauth2.NewClient(ctx, ts)
 	client := github.NewClient(tc)
-	pullTitle := "Update"
 	pullBase := string(baseBranch.Name())
 	pullHead := string(targetBranch)
+	pullTitle := changes.Title()
 	pullBody := changes.Message()
 	_, res, err := client.PullRequests.Create(context.Background(), *ownerName, *repoName, &github.NewPullRequest{
 		Title: &pullTitle,