Provide diff and patch API endpoints (#11751)

* Provide diff and patch API endpoints

The diff and patch endpoints on the main routes are not accessible by token
therefore we provide new API based endpoints for these

Fix #10923

Signed-off-by: Andrew Thornton <art27@cantab.net>

* placate swagger

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Make the response an actual string

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>

4 files changed, 182 insertions, 0 deletions

diff --git a/modules/context/api.go b/modules/context/api.go
index 5d91ac49a3..acecf8f264 100644
--- a/modules/context/api.go
+++ b/modules/context/api.go
@@ -65,6 +65,10 @@ type APINotFound struct{}
 // swagger:response redirect
 type APIRedirect struct{}
 
+//APIString is a string response
+// swagger:response string
+type APIString string
+
 // Error responds with an error message to client with given obj as the message.
 // If status is 500, also it prints error to log.
 func (ctx *APIContext) Error(status int, title string, obj interface{}) {
diff --git a/routers/api/v1/api.go b/routers/api/v1/api.go
index 0f8a0326e9..1ae4e7a58f 100644
--- a/routers/api/v1/api.go
+++ b/routers/api/v1/api.go
@@ -796,6 +796,8 @@ func RegisterRoutes(m *macaron.Macaron) {
 					m.Group("/:index", func() {
 						m.Combo("").Get(repo.GetPullRequest).
 							Patch(reqToken(), reqRepoWriter(models.UnitTypePullRequests), bind(api.EditPullRequestOption{}), repo.EditPullRequest)
+						m.Get(".diff", repo.DownloadPullDiff)
+						m.Get(".patch", repo.DownloadPullPatch)
 						m.Combo("/merge").Get(repo.IsPullRequestMerged).
 							Post(reqToken(), mustNotBeArchived, bind(auth.MergePullRequestForm{}), repo.MergePullRequest)
 						m.Group("/reviews", func() {
diff --git a/routers/api/v1/repo/pull.go b/routers/api/v1/repo/pull.go
index bddf4e48f7..284c231628 100644
--- a/routers/api/v1/repo/pull.go
+++ b/routers/api/v1/repo/pull.go
@@ -169,6 +169,88 @@ func GetPullRequest(ctx *context.APIContext) {
 	ctx.JSON(http.StatusOK, convert.ToAPIPullRequest(pr))
 }
 
+// DownloadPullDiff render a pull's raw diff
+func DownloadPullDiff(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/pulls/{index}.diff repository repoDownloadPullDiff
+	// ---
+	// summary: Get a pull request diff
+	// produces:
+	// - text/plain
+	// 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
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/string"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	DownloadPullDiffOrPatch(ctx, false)
+}
+
+// DownloadPullPatch render a pull's raw patch
+func DownloadPullPatch(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/pulls/{index}.patch repository repoDownloadPullPatch
+	// ---
+	// summary: Get a pull request patch file
+	// produces:
+	// - text/plain
+	// 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
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/string"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	DownloadPullDiffOrPatch(ctx, true)
+}
+
+// DownloadPullDiffOrPatch render a pull's raw diff or patch
+func DownloadPullDiffOrPatch(ctx *context.APIContext, patch bool) {
+	pr, err := models.GetPullRequestByIndex(ctx.Repo.Repository.ID, ctx.ParamsInt64(":index"))
+	if err != nil {
+		if models.IsErrPullRequestNotExist(err) {
+			ctx.NotFound()
+		} else {
+			ctx.InternalServerError(err)
+		}
+		return
+	}
+
+	if err := pull_service.DownloadDiffOrPatch(pr, ctx, patch); err != nil {
+		ctx.InternalServerError(err)
+		return
+	}
+}
+
 // CreatePullRequest does what it says
 func CreatePullRequest(ctx *context.APIContext, form api.CreatePullRequestOption) {
 	// swagger:operation POST /repos/{owner}/{repo}/pulls repository repoCreatePullRequest
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 687a6bc5e4..d90fafd75f 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -6649,6 +6649,94 @@
         }
       }
     },
+    "/repos/{owner}/{repo}/pulls/{index}.diff": {
+      "get": {
+        "produces": [
+          "text/plain"
+        ],
+        "tags": [
+          "repository"
+        ],
+        "summary": "Get a pull request diff",
+        "operationId": "repoDownloadPullDiff",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "format": "int64",
+            "description": "index of the pull request to get",
+            "name": "index",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/string"
+          },
+          "404": {
+            "$ref": "#/responses/notFound"
+          }
+        }
+      }
+    },
+    "/repos/{owner}/{repo}/pulls/{index}.patch": {
+      "get": {
+        "produces": [
+          "text/plain"
+        ],
+        "tags": [
+          "repository"
+        ],
+        "summary": "Get a pull request patch file",
+        "operationId": "repoDownloadPullPatch",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "integer",
+            "format": "int64",
+            "description": "index of the pull request to get",
+            "name": "index",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "$ref": "#/responses/string"
+          },
+          "404": {
+            "$ref": "#/responses/notFound"
+          }
+        }
+      }
+    },
     "/repos/{owner}/{repo}/pulls/{index}/merge": {
       "get": {
         "produces": [
@@ -15209,6 +15297,12 @@
     "redirect": {
       "description": "APIRedirect is a redirect response"
     },
+    "string": {
+      "description": "APIString is a string response",
+      "schema": {
+        "type": "string"
+      }
+    },
     "validationError": {
       "description": "APIValidationError is error format response related to input validation",
       "headers": {