Refactor various strings (#17784)

Fixes #16478

Co-authored-by: Gusted <williamzijl7@hotmail.com>

Co-authored-by: Gusted <williamzijl7@hotmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

8 files changed, 30 insertions, 19 deletions

diff --git a/modules/convert/pull.go b/modules/convert/pull.go
index ea1e4bb3c2..a5e7d9608a 100644
--- a/modules/convert/pull.go
+++ b/modules/convert/pull.go
@@ -79,7 +79,7 @@ func ToAPIPullRequest(pr *models.PullRequest, doer *user_model.User) *api.PullRe
 		},
 		Head: &api.PRBranchInfo{
 			Name:   pr.HeadBranch,
-			Ref:    fmt.Sprintf("refs/pull/%d/head", pr.Index),
+			Ref:    fmt.Sprintf(git.PullPrefix+"%d/head", pr.Index),
 			RepoID: -1,
 		},
 	}
diff --git a/modules/git/commit.go b/modules/git/commit.go
index fe2c2b9774..26c5445e2a 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -141,7 +141,7 @@ func CommitChangesWithArgs(repoPath string, args []string, opts CommitChangesOpt
 func AllCommitsCount(repoPath string, hidePRRefs bool, files ...string) (int64, error) {
 	args := []string{"--all", "--count"}
 	if hidePRRefs {
-		args = append([]string{"--exclude=refs/pull/*"}, args...)
+		args = append([]string{"--exclude=" + PullPrefix + "*"}, args...)
 	}
 	cmd := NewCommand("rev-list")
 	cmd.AddArguments(args...)
diff --git a/modules/git/ref.go b/modules/git/ref.go
index 2a2798b18f..9fd071ce58 100644
--- a/modules/git/ref.go
+++ b/modules/git/ref.go
@@ -6,6 +6,15 @@ package git
 
 import "strings"
 
+const (
+	// RemotePrefix is the base directory of the remotes information of git.
+	RemotePrefix = "refs/remotes/"
+	// PullPrefix is the base directory of the pull information of git.
+	PullPrefix = "refs/pull/"
+
+	pullLen = len(PullPrefix)
+)
+
 // Reference represents a Git ref.
 type Reference struct {
 	Name   string
@@ -24,17 +33,17 @@ func (ref *Reference) ShortName() string {
 	if ref == nil {
 		return ""
 	}
-	if strings.HasPrefix(ref.Name, "refs/heads/") {
-		return ref.Name[11:]
+	if strings.HasPrefix(ref.Name, BranchPrefix) {
+		return strings.TrimPrefix(ref.Name, BranchPrefix)
 	}
-	if strings.HasPrefix(ref.Name, "refs/tags/") {
-		return ref.Name[10:]
+	if strings.HasPrefix(ref.Name, TagPrefix) {
+		return strings.TrimPrefix(ref.Name, TagPrefix)
 	}
-	if strings.HasPrefix(ref.Name, "refs/remotes/") {
-		return ref.Name[13:]
+	if strings.HasPrefix(ref.Name, RemotePrefix) {
+		return strings.TrimPrefix(ref.Name, RemotePrefix)
 	}
-	if strings.HasPrefix(ref.Name, "refs/pull/") && strings.IndexByte(ref.Name[10:], '/') > -1 {
-		return ref.Name[10 : strings.IndexByte(ref.Name[10:], '/')+10]
+	if strings.HasPrefix(ref.Name, PullPrefix) && strings.IndexByte(ref.Name[pullLen:], '/') > -1 {
+		return ref.Name[pullLen : strings.IndexByte(ref.Name[pullLen:], '/')+pullLen]
 	}
 
 	return ref.Name
@@ -45,16 +54,16 @@ func (ref *Reference) RefGroup() string {
 	if ref == nil {
 		return ""
 	}
-	if strings.HasPrefix(ref.Name, "refs/heads/") {
+	if strings.HasPrefix(ref.Name, BranchPrefix) {
 		return "heads"
 	}
-	if strings.HasPrefix(ref.Name, "refs/tags/") {
+	if strings.HasPrefix(ref.Name, TagPrefix) {
 		return "tags"
 	}
-	if strings.HasPrefix(ref.Name, "refs/remotes/") {
+	if strings.HasPrefix(ref.Name, RemotePrefix) {
 		return "remotes"
 	}
-	if strings.HasPrefix(ref.Name, "refs/pull/") && strings.IndexByte(ref.Name[10:], '/') > -1 {
+	if strings.HasPrefix(ref.Name, PullPrefix) && strings.IndexByte(ref.Name[pullLen:], '/') > -1 {
 		return "pull"
 	}
 	return ""
diff --git a/modules/git/repo.go b/modules/git/repo.go
index 3ff2b6fe2d..3950bb4a92 100644
--- a/modules/git/repo.go
+++ b/modules/git/repo.go
@@ -371,7 +371,7 @@ func parseSize(objects string) *CountObject {
 
 // GetLatestCommitTime returns time for latest commit in repository (across all branches)
 func GetLatestCommitTime(repoPath string) (time.Time, error) {
-	cmd := NewCommand("for-each-ref", "--sort=-committerdate", "refs/heads/", "--count", "1", "--format=%(committerdate)")
+	cmd := NewCommand("for-each-ref", "--sort=-committerdate", BranchPrefix, "--count", "1", "--format=%(committerdate)")
 	stdout, err := cmd.RunInDir(repoPath)
 	if err != nil {
 		return time.Time{}, err
diff --git a/modules/git/repo_compare.go b/modules/git/repo_compare.go
index 303bb5bc03..4342eb4b2f 100644
--- a/modules/git/repo_compare.go
+++ b/modules/git/repo_compare.go
@@ -33,7 +33,7 @@ func (repo *Repository) GetMergeBase(tmpRemote string, base, head string) (strin
 	}
 
 	if tmpRemote != "origin" {
-		tmpBaseName := "refs/remotes/" + tmpRemote + "/tmp_" + base
+		tmpBaseName := RemotePrefix + tmpRemote + "/tmp_" + base
 		// Fetch commit into a temporary branch in order to be able to handle commits and tags
 		_, err := NewCommandContext(repo.Ctx, "fetch", tmpRemote, base+":"+tmpBaseName).RunInDir(repo.Path)
 		if err == nil {
diff --git a/modules/git/repo_ref_nogogit.go b/modules/git/repo_ref_nogogit.go
index 790b717d38..5c9ed57ea1 100644
--- a/modules/git/repo_ref_nogogit.go
+++ b/modules/git/repo_ref_nogogit.go
@@ -66,7 +66,7 @@ func (repo *Repository) GetRefsFiltered(pattern string) ([]*Reference, error) {
 		refName = refName[:len(refName)-1]
 
 		// refName cannot be HEAD but can be remotes or stash
-		if strings.HasPrefix(refName, "/refs/remotes/") || refName == "/refs/stash" {
+		if strings.HasPrefix(refName, RemotePrefix) || refName == "/refs/stash" {
 			continue
 		}
 
diff --git a/modules/gitgraph/graph.go b/modules/gitgraph/graph.go
index 8505678639..cf994bfd4c 100644
--- a/modules/gitgraph/graph.go
+++ b/modules/gitgraph/graph.go
@@ -29,7 +29,7 @@ func GetCommitGraph(r *git.Repository, page int, maxAllowedColors int, hidePRRef
 	args = append(args, "--graph", "--date-order", "--decorate=full")
 
 	if hidePRRefs {
-		args = append(args, "--exclude=refs/pull/*")
+		args = append(args, "--exclude="+git.PullPrefix+"*")
 	}
 
 	if len(branches) == 0 {
diff --git a/modules/migration/pullrequest.go b/modules/migration/pullrequest.go
index 9ca9a70b7d..498768ea48 100644
--- a/modules/migration/pullrequest.go
+++ b/modules/migration/pullrequest.go
@@ -8,6 +8,8 @@ package migration
 import (
 	"fmt"
 	"time"
+
+	"code.gitea.io/gitea/modules/git"
 )
 
 // PullRequest defines a standard pull request information
@@ -43,7 +45,7 @@ func (p *PullRequest) IsForkPullRequest() bool {
 
 // GetGitRefName returns pull request relative path to head
 func (p PullRequest) GetGitRefName() string {
-	return fmt.Sprintf("refs/pull/%d/head", p.Number)
+	return fmt.Sprintf(git.PullPrefix+"%d/head", p.Number)
 }
 
 // PullRequestBranch represents a pull request branch