feat: implement commit comparison feature in Gitea client (#659)

See the API: https://github.com/go-gitea/gitea/pull/30349

- Add a new file `repo_compare.go` with package `gitea` and `Compare` struct
- Implement `CompareCommits` method in `Client` struct in `repo_compare.go`
- Add `version1_22_0` constant in `version.go`

Signed-off-by: appleboy <appleboy.tw@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-on: https://gitea.com/gitea/go-sdk/pulls/659
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: appleboy <appleboy.tw@gmail.com>
Co-committed-by: appleboy <appleboy.tw@gmail.com>

gitea/repo_compare.go

@@ -0,0 +1,33 @@
+// Copyright 2024 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 gitea
+
+import "fmt"
+
+// Compare represents a comparison between two commits.
+type Compare struct {
+	TotalCommits int       `json:"total_commits"` // Total number of commits in the comparison.
+	Commits      []*Commit `json:"commits"`       // List of commits in the comparison.
+}
+
+// CompareCommits compares two commits in a repository.
+func (c *Client) CompareCommits(user, repo, prev, current string) (*Compare, *Response, error) {
+	if err := c.checkServerVersionGreaterThanOrEqual(version1_22_0); err != nil {
+		return nil, nil, err
+	}
+	if err := escapeValidatePathSegments(&user, &repo, &prev, &current); err != nil {
+		return nil, nil, err
+	}
+
+	basehead := fmt.Sprintf("%s...%s", prev, current)
+
+	apiResp := new(Compare)
+	resp, err := c.getParsedResponse(
+		"GET",
+		fmt.Sprintf("/repos/%s/%s/compare/%s", user, repo, basehead),
+		nil, nil, apiResp,
+	)
+	return apiResp, resp, err
+}

gitea/version.go

@@ -69,6 +69,7 @@ var (
 	version1_15_0 = version.Must(version.NewVersion("1.15.0"))
 	version1_16_0 = version.Must(version.NewVersion("1.16.0"))
 	version1_17_0 = version.Must(version.NewVersion("1.17.0"))
+	version1_22_0 = version.Must(version.NewVersion("1.22.0"))
 )
 
 // ErrUnknownVersion is an unknown version from the API