Feat: Adds Ability to Merge MR (#147)

This adds the ability to merge an MR from within `gitlab.nvim` directly. If the reviewer is open, it'll be closed automatically. Users may configure whether they'd like to squash commits on the merge, as well as whether they'd like to delete the original source branch on a merge.

If squashing, users are prompted to provide an optional custom squash message for the squash commit.

cmd/merge.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+type AcceptMergeRequestRequest struct {
+	Squash        bool   `json:"squash"`
+	SquashMessage string `json:"squash_message"`
+	DeleteBranch  bool   `json:"delete_branch"`
+}
+
+/* acceptAndMergeHandler merges a given merge request into the target branch */
+func (a *api) acceptAndMergeHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Access-Control-Allow-Methods", http.MethodGet)
+	if r.Method != http.MethodPost {
+		handleError(w, InvalidRequestError{}, "Expected POST", http.StatusMethodNotAllowed)
+		return
+	}
+
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		handleError(w, err, "Could not read request body", http.StatusBadRequest)
+		return
+	}
+
+	var acceptAndMergeRequest AcceptMergeRequestRequest
+	err = json.Unmarshal(body, &acceptAndMergeRequest)
+	if err != nil {
+		handleError(w, err, "Could not unmarshal request body", http.StatusBadRequest)
+		return
+	}
+
+	opts := gitlab.AcceptMergeRequestOptions{
+		Squash:                   &acceptAndMergeRequest.Squash,
+		ShouldRemoveSourceBranch: &acceptAndMergeRequest.DeleteBranch,
+	}
+
+	if acceptAndMergeRequest.SquashMessage != "" {
+		opts.SquashCommitMessage = &acceptAndMergeRequest.SquashMessage
+	}
+
+	_, res, err := a.client.AcceptMergeRequest(a.projectInfo.ProjectId, a.projectInfo.MergeId, &opts)
+
+	if err != nil {
+		handleError(w, err, "Could not merge MR", http.StatusInternalServerError)
+		return
+	}
+
+	if res.StatusCode >= 300 {
+		handleError(w, GenericError{endpoint: "/merge"}, "Could not merge MR", res.StatusCode)
+		return
+	}
+
+	response := SuccessResponse{
+		Status:  http.StatusOK,
+		Message: "MR merged successfully",
+	}
+
+	w.WriteHeader(http.StatusOK)
+
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		handleError(w, err, "Could not encode response", http.StatusInternalServerError)
+	}
+}

cmd/merge_test.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+func acceptAndMergeFn(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error) {
+	return &gitlab.MergeRequest{}, makeResponse(http.StatusOK), nil
+}
+
+func acceptAndMergeFnErr(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error) {
+	return nil, nil, errors.New("Some error from Gitlab")
+}
+
+func acceptAndMergeNon200(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error) {
+	return nil, makeResponse(http.StatusSeeOther), nil
+}
+
+func TestAcceptAndMergeHandler(t *testing.T) {
+	t.Run("Accepts and merges a merge request", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/merge", AcceptMergeRequestRequest{})
+		server, _ := createRouterAndApi(fakeClient{acceptAndMergeFn: acceptAndMergeFn})
+		data := serveRequest(t, server, request, SuccessResponse{})
+		assert(t, data.Message, "MR merged successfully")
+		assert(t, data.Status, http.StatusOK)
+	})
+
+	t.Run("Disallows non-POST methods", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/merge", AcceptMergeRequestRequest{})
+		server, _ := createRouterAndApi(fakeClient{acceptAndMergeFn: acceptAndMergeFn})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkBadMethod(t, *data, http.MethodPost)
+	})
+
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/merge", AcceptMergeRequestRequest{})
+		server, _ := createRouterAndApi(fakeClient{acceptAndMergeFn: acceptAndMergeFnErr})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkErrorFromGitlab(t, *data, "Could not merge MR")
+	})
+
+	t.Run("Handles non-200s from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/merge", AcceptMergeRequestRequest{})
+		server, _ := createRouterAndApi(fakeClient{acceptAndMergeFn: acceptAndMergeNon200})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkNon200(t, *data, "Could not merge MR", "/merge")
+	})
+}

cmd/server.go

@@ -105,6 +105,7 @@ func createRouterAndApi(client ClientInterface, optFuncs ...optFunc) (*http.Serv
 	m.HandleFunc("/shutdown", a.shutdownHandler)
 	m.HandleFunc("/approve", a.approveHandler)
 	m.HandleFunc("/comment", a.commentHandler)
+	m.HandleFunc("/merge", a.acceptAndMergeHandler)
 	m.HandleFunc("/discussions/list", a.listDiscussionsHandler)
 	m.HandleFunc("/discussions/resolve", a.discussionsResolveHandler)
 	m.HandleFunc("/info", a.infoHandler)

cmd/test.go

@@ -20,6 +20,7 @@ The FakeHandlerClient is used to create a fake gitlab client for testing our han
 type fakeClient struct {
 	getMergeRequestFn                func(pid interface{}, mergeRequest int, opt *gitlab.GetMergeRequestsOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
 	updateMergeRequestFn             func(pid interface{}, mergeRequest int, opt *gitlab.UpdateMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
+	acceptAndMergeFn                 func(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
 	unapprorveMergeRequestFn         func(pid interface{}, mr int, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error)
 	uploadFile                       func(pid interface{}, content io.Reader, filename string, options ...gitlab.RequestOptionFunc) (*gitlab.ProjectFile, *gitlab.Response, error)
 	getMergeRequestDiffVersions      func(pid interface{}, mergeRequest int, opt *gitlab.GetMergeRequestDiffVersionsOptions, options ...gitlab.RequestOptionFunc) ([]*gitlab.MergeRequestDiffVersion, *gitlab.Response, error)
@@ -46,6 +47,10 @@ type Author struct {
 	WebURL    string `json:"web_url"`
 }
 
+func (f fakeClient) AcceptMergeRequest(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error) {
+	return f.acceptAndMergeFn(pid, mergeRequest, opt, options...)
+}
+
 func (f fakeClient) GetMergeRequest(pid interface{}, mergeRequest int, opt *gitlab.GetMergeRequestsOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error) {
 	return f.getMergeRequestFn(pid, mergeRequest, opt, options...)
 }

cmd/types.go

@@ -36,6 +36,7 @@ func (e InvalidRequestError) Error() string {
 /* The ClientInterface interface implements all the methods that our handlers need */
 type ClientInterface interface {
 	GetMergeRequest(pid interface{}, mr int, opt *gitlab.GetMergeRequestsOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
+	AcceptMergeRequest(pid interface{}, mergeRequest int, opt *gitlab.AcceptMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
 	UpdateMergeRequest(pid interface{}, mr int, opt *gitlab.UpdateMergeRequestOptions, options ...gitlab.RequestOptionFunc) (*gitlab.MergeRequest, *gitlab.Response, error)
 	UploadFile(pid interface{}, content io.Reader, filename string, options ...gitlab.RequestOptionFunc) (*gitlab.ProjectFile, *gitlab.Response, error)
 	GetMergeRequestDiffVersions(pid interface{}, mr int, opt *gitlab.GetMergeRequestDiffVersionsOptions, options ...gitlab.RequestOptionFunc) ([]*gitlab.MergeRequestDiffVersion, *gitlab.Response, error)