Add API endpoint to get changed files of a PR (#21177)

This adds an api endpoint `/files` to PRs that allows to get a list of changed files.

built upon #18228, reviews there are included
closes #654

Co-authored-by: Anton Bracke <anton@ju60.de>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/fixtures/pull_request.yml

@@ -60,8 +60,8 @@
   head_repo_id: 1
   base_repo_id: 1
   head_branch: pr-to-update
-  base_branch: branch1
-  merge_base: 1234567890abcdef
+  base_branch: branch2
+  merge_base: 985f0301dba5e7b34be866819cd15ad3d8f508ee
   has_merged: false
 
 -

modules/convert/convert.go

@@ -27,6 +27,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/services/gitdiff"
 	webhook_service "code.gitea.io/gitea/services/webhook"
 )
 
@@ -414,3 +415,36 @@ func ToLFSLock(l *git_model.LFSLock) *api.LFSLock {
 		},
 	}
 }
+
+// ToChangedFile convert a gitdiff.DiffFile to api.ChangedFile
+func ToChangedFile(f *gitdiff.DiffFile, repo *repo_model.Repository, commit string) *api.ChangedFile {
+	status := "changed"
+	if f.IsDeleted {
+		status = "deleted"
+	} else if f.IsCreated {
+		status = "added"
+	} else if f.IsRenamed && f.Type == gitdiff.DiffFileCopy {
+		status = "copied"
+	} else if f.IsRenamed && f.Type == gitdiff.DiffFileRename {
+		status = "renamed"
+	} else if f.Addition == 0 && f.Deletion == 0 {
+		status = "unchanged"
+	}
+
+	file := &api.ChangedFile{
+		Filename:    f.GetDiffFileName(),
+		Status:      status,
+		Additions:   f.Addition,
+		Deletions:   f.Deletion,
+		Changes:     f.Addition + f.Deletion,
+		HTMLURL:     fmt.Sprint(repo.HTMLURL(), "/src/commit/", commit, "/", util.PathEscapeSegments(f.GetDiffFileName())),
+		ContentsURL: fmt.Sprint(repo.APIURL(), "/contents/", util.PathEscapeSegments(f.GetDiffFileName()), "?ref=", commit),
+		RawURL:      fmt.Sprint(repo.HTMLURL(), "/raw/commit/", commit, "/", util.PathEscapeSegments(f.GetDiffFileName())),
+	}
+
+	if status == "rename" {
+		file.PreviousFilename = f.OldName
+	}
+
+	return file
+}

modules/structs/pull.go

@@ -95,3 +95,16 @@ type EditPullRequestOption struct {
 	RemoveDeadline      *bool      `json:"unset_due_date"`
 	AllowMaintainerEdit *bool      `json:"allow_maintainer_edit"`
 }
+
+// ChangedFile store information about files affected by the pull request
+type ChangedFile struct {
+	Filename         string `json:"filename"`
+	PreviousFilename string `json:"previous_filename,omitempty"`
+	Status           string `json:"status"`
+	Additions        int    `json:"additions"`
+	Deletions        int    `json:"deletions"`
+	Changes          int    `json:"changes"`
+	HTMLURL          string `json:"html_url,omitempty"`
+	ContentsURL      string `json:"contents_url,omitempty"`
+	RawURL           string `json:"raw_url,omitempty"`
+}

routers/api/v1/api.go

@@ -1002,6 +1002,7 @@ func Routes(ctx gocontext.Context) *web.Route {
 						m.Get(".{diffType:diff|patch}", repo.DownloadPullDiffOrPatch)
 						m.Post("/update", reqToken(), repo.UpdatePullRequest)
 						m.Get("/commits", repo.GetPullRequestCommits)
+						m.Get("/files", repo.GetPullRequestFiles)
 						m.Combo("/merge").Get(repo.IsPullRequestMerged).
 							Post(reqToken(), mustNotBeArchived, bind(forms.MergePullRequestForm{}), repo.MergePullRequest).
 							Delete(reqToken(), mustNotBeArchived, repo.CancelScheduledAutoMerge)

routers/api/v1/repo/pull.go

@@ -26,13 +26,15 @@ import (
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
+	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/routers/api/v1/utils"
 	asymkey_service "code.gitea.io/gitea/services/asymkey"
 	"code.gitea.io/gitea/services/automerge"
 	"code.gitea.io/gitea/services/forms"
+	"code.gitea.io/gitea/services/gitdiff"
 	issue_service "code.gitea.io/gitea/services/issue"
 	pull_service "code.gitea.io/gitea/services/pull"
 	repo_service "code.gitea.io/gitea/services/repository"
@@ -1323,3 +1325,137 @@ func GetPullRequestCommits(ctx *context.APIContext) {
 
 	ctx.JSON(http.StatusOK, &apiCommits)
 }
+
+// GetPullRequestFiles gets all changed files associated with a given PR
+func GetPullRequestFiles(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/pulls/{index}/files repository repoGetPullRequestFiles
+	// ---
+	// summary: Get changed files for a pull request
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: index
+	//   in: path
+	//   description: index of the pull request to get
+	//   type: integer
+	//   format: int64
+	//   required: true
+	// - name: skip-to
+	//   in: query
+	//   description: skip to given file
+	//   type: string
+	// - name: whitespace
+	//   in: query
+	//   description: whitespace behavior
+	//   type: string
+	//   enum: [ignore-all, ignore-change, ignore-eol, show-all]
+	// - name: page
+	//   in: query
+	//   description: page number of results to return (1-based)
+	//   type: integer
+	// - name: limit
+	//   in: query
+	//   description: page size of results
+	//   type: integer
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ChangedFileList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	pr, err := issues_model.GetPullRequestByIndex(ctx, ctx.Repo.Repository.ID, ctx.ParamsInt64(":index"))
+	if err != nil {
+		if issues_model.IsErrPullRequestNotExist(err) {
+			ctx.NotFound()
+		} else {
+			ctx.Error(http.StatusInternalServerError, "GetPullRequestByIndex", err)
+		}
+		return
+	}
+
+	if err := pr.LoadBaseRepo(); err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+
+	if err := pr.LoadHeadRepo(); err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+
+	baseGitRepo := ctx.Repo.GitRepo
+
+	var prInfo *git.CompareInfo
+	if pr.HasMerged {
+		prInfo, err = baseGitRepo.GetCompareInfo(pr.BaseRepo.RepoPath(), pr.MergeBase, pr.GetGitRefName(), true, false)
+	} else {
+		prInfo, err = baseGitRepo.GetCompareInfo(pr.BaseRepo.RepoPath(), pr.BaseBranch, pr.GetGitRefName(), true, false)
+	}
+	if err != nil {
+		ctx.ServerError("GetCompareInfo", err)
+		return
+	}
+
+	headCommitID, err := baseGitRepo.GetRefCommitID(pr.GetGitRefName())
+	if err != nil {
+		ctx.ServerError("GetRefCommitID", err)
+		return
+	}
+
+	startCommitID := prInfo.MergeBase
+	endCommitID := headCommitID
+
+	maxLines, maxFiles := setting.Git.MaxGitDiffLines, setting.Git.MaxGitDiffFiles
+
+	diff, err := gitdiff.GetDiff(baseGitRepo,
+		&gitdiff.DiffOptions{
+			BeforeCommitID:     startCommitID,
+			AfterCommitID:      endCommitID,
+			SkipTo:             ctx.FormString("skip-to"),
+			MaxLines:           maxLines,
+			MaxLineCharacters:  setting.Git.MaxGitDiffLineCharacters,
+			MaxFiles:           maxFiles,
+			WhitespaceBehavior: gitdiff.GetWhitespaceFlag(ctx.FormString("whitespace")),
+		})
+	if err != nil {
+		ctx.ServerError("GetDiff", err)
+		return
+	}
+
+	listOptions := utils.GetListOptions(ctx)
+
+	totalNumberOfFiles := diff.NumFiles
+	totalNumberOfPages := int(math.Ceil(float64(totalNumberOfFiles) / float64(listOptions.PageSize)))
+
+	start, end := listOptions.GetStartEnd()
+
+	if end > totalNumberOfFiles {
+		end = totalNumberOfFiles
+	}
+
+	apiFiles := make([]*api.ChangedFile, 0, end-start)
+	for i := start; i < end; i++ {
+		apiFiles = append(apiFiles, convert.ToChangedFile(diff.Files[i], pr.HeadRepo, endCommitID))
+	}
+
+	ctx.SetLinkHeader(totalNumberOfFiles, listOptions.PageSize)
+	ctx.SetTotalCountHeader(int64(totalNumberOfFiles))
+
+	ctx.RespHeader().Set("X-Page", strconv.Itoa(listOptions.Page))
+	ctx.RespHeader().Set("X-PerPage", strconv.Itoa(listOptions.PageSize))
+	ctx.RespHeader().Set("X-PageCount", strconv.Itoa(totalNumberOfPages))
+	ctx.RespHeader().Set("X-HasMore", strconv.FormatBool(listOptions.Page < totalNumberOfPages))
+	ctx.AppendAccessControlExposeHeaders("X-Page", "X-PerPage", "X-PageCount", "X-HasMore")
+
+	ctx.JSON(http.StatusOK, &apiFiles)
+}

routers/api/v1/swagger/repo.go

@@ -254,6 +254,28 @@ type swaggerCommitList struct {
 	Body []api.Commit `json:"body"`
 }
 
+// ChangedFileList
+// swagger:response ChangedFileList
+type swaggerChangedFileList struct {
+	// The current page
+	Page int `json:"X-Page"`
+
+	// Commits per page
+	PerPage int `json:"X-PerPage"`
+
+	// Total commit count
+	Total int `json:"X-Total"`
+
+	// Total number of pages
+	PageCount int `json:"X-PageCount"`
+
+	// True if there is another page
+	HasMore bool `json:"X-HasMore"`
+
+	// in: body
+	Body []api.ChangedFile `json:"body"`
+}
+
 // Note
 // swagger:response Note
 type swaggerNote struct {