refactor: optimize PR title generation and expand test coverage (#549)

- Import "regexp" package in pull_create.go
- Replace existing code for `GetDefaultPRTitle` with a more efficient regular expression approach
- Add a new test file pull_create_test.go with a test function for `GetDefaultPRTitle`

Signed-off-by: appleboy <appleboy.tw@gmail.com>
Reviewed-on: https://gitea.com/gitea/tea/pulls/549
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: techknowlogick <techknowlogick@noreply.gitea.io>
Co-authored-by: appleboy <appleboy.tw@gmail.com>
Co-committed-by: appleboy <appleboy.tw@gmail.com>

modules/task/pull_create.go

@@ -6,6 +6,7 @@ package task
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 
 	"code.gitea.io/sdk/gitea"
@@ -16,6 +17,12 @@ import (
 	"code.gitea.io/tea/modules/utils"
 )
 
+var (
+	spaceRegex  = regexp.MustCompile(`[\s_-]+`)
+	noSpace     = regexp.MustCompile(`^[^a-zA-Z\s]*`)
+	consecutive = regexp.MustCompile(`[\s]{2,}`)
+)
+
 // CreatePull creates a PR in the given repo and prints the result
 func CreatePull(ctx *context.TeaContext, base, head string, allowMaintainerEdits bool, opts *gitea.CreateIssueOption) (err error) {
 	// default is default branch
@@ -65,7 +72,6 @@ func CreatePull(ctx *context.TeaContext, base, head string, allowMaintainerEdits
 		Milestone: opts.Milestone,
 		Deadline:  opts.Deadline,
 	})
-
 	if err != nil {
 		return fmt.Errorf("could not create PR from %s to %s:%s: %s", head, ctx.Owner, base, err)
 	}
@@ -133,13 +139,18 @@ func GetHeadSpec(owner, branch, baseOwner string) string {
 }
 
 // GetDefaultPRTitle transforms a string like a branchname to a readable text
-func GetDefaultPRTitle(head string) string {
-	title := head
-	if strings.Contains(title, ":") {
-		title = strings.SplitN(title, ":", 2)[1]
+func GetDefaultPRTitle(header string) string {
+	// Extract the part after the last colon in the input string
+	colonIndex := strings.LastIndex(header, ":")
+	if colonIndex != -1 {
+		header = header[colonIndex+1:]
 	}
-	title = strings.Replace(title, "-", " ", -1)
-	title = strings.Replace(title, "_", " ", -1)
+
+	title := noSpace.ReplaceAllString(header, "")
+	title = spaceRegex.ReplaceAllString(title, " ")
+	title = strings.TrimSpace(title)
 	title = strings.Title(strings.ToLower(title))
+	title = consecutive.ReplaceAllString(title, " ")
+
 	return title
 }

modules/task/pull_create_test.go

@@ -0,0 +1,28 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package task
+
+import "testing"
+
+func TestGetDefaultPRTitle(t *testing.T) {
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{input: "Add new feature", want: "Add New Feature"},
+		{input: "update-docs: Fix typo", want: "Fix Typo"},
+		{input: "remove_long-string", want: "Remove Long String"},
+		{input: "Replace_Underscores_With_Spaces", want: "Replace Underscores With Spaces"},
+		{input: "  leading-and-trailing-spaces ", want: "Leading And Trailing Spaces"},
+		{input: "-----No--Upper--Case-----", want: "No Upper Case"},
+		{input: "", want: ""},
+	}
+	for _, test := range tests {
+		got := GetDefaultPRTitle(test.input)
+		if got != test.want {
+			t.Errorf("GetDefaultPRTitle(%q) = %q, want %q", test.input, got, test.want)
+		}
+	}
+}