Simplify Go Endpoints + Add Tests (#120)

This MR represents a major refactor of the Go codebase, as well as introducing tests for the handlers. The MR also introduces an endpoint to shutdown or restart the Go server, which may be useful for clients who want to refresh the state of the plugin after checking out branches. Finally, this MR adds a contributing document for users who want to make feature changes.

cmd/comment_test.go

@@ -0,0 +1,139 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+func createMergeRequestDiscussion(pid interface{}, mergeRequest int, opt *gitlab.CreateMergeRequestDiscussionOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Discussion, *gitlab.Response, error) {
+	return &gitlab.Discussion{Notes: []*gitlab.Note{{}}}, makeResponse(http.StatusOK), nil
+}
+
+func createMergeRequestDiscussionNon200(pid interface{}, mergeRequest int, opt *gitlab.CreateMergeRequestDiscussionOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Discussion, *gitlab.Response, error) {
+	return nil, makeResponse(http.StatusSeeOther), nil
+}
+
+func createMergeRequestDiscussionErr(pid interface{}, mergeRequest int, opt *gitlab.CreateMergeRequestDiscussionOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Discussion, *gitlab.Response, error) {
+	return nil, nil, errors.New("Some error from Gitlab")
+}
+
+func TestPostComment(t *testing.T) {
+	t.Run("Creates a new note (unlinked comment)", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/comment", PostCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{createMergeRequestDiscussion: createMergeRequestDiscussion})
+		data := serveRequest(t, server, request, CommentResponse{})
+		assert(t, data.SuccessResponse.Message, "Note created successfully")
+		assert(t, data.SuccessResponse.Status, http.StatusOK)
+	})
+
+	t.Run("Creates a new comment", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/comment", PostCommentRequest{FileName: "some_file.txt"})
+		server, _ := createRouterAndApi(fakeClient{createMergeRequestDiscussion: createMergeRequestDiscussion})
+		data := serveRequest(t, server, request, CommentResponse{})
+		assert(t, data.SuccessResponse.Message, "Comment created successfully")
+		assert(t, data.SuccessResponse.Status, http.StatusOK)
+	})
+
+	t.Run("Creates a new multiline comment", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/comment", PostCommentRequest{
+			FileName: "some_file.txt",
+			LineRange: &LineRange{
+				StartRange: &LinePosition{}, /* These would have real data */
+				EndRange:   &LinePosition{},
+			},
+		})
+		server, _ := createRouterAndApi(fakeClient{createMergeRequestDiscussion: createMergeRequestDiscussion})
+		data := serveRequest(t, server, request, CommentResponse{})
+		assert(t, data.SuccessResponse.Message, "Multiline Comment created successfully")
+		assert(t, data.SuccessResponse.Status, http.StatusOK)
+	})
+
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/comment", PostCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{createMergeRequestDiscussion: createMergeRequestDiscussionErr})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkErrorFromGitlab(t, *data, "Could not create discussion")
+	})
+
+	t.Run("Handles non-200s from Gitlab", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPost, "/comment", PostCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{createMergeRequestDiscussion: createMergeRequestDiscussionNon200})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkNon200(t, *data, "Could not create discussion", "/comment")
+	})
+}
+
+func deleteMergeRequestDiscussionNote(pid interface{}, mergeRequest int, discussion string, note int, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error) {
+	return makeResponse(http.StatusOK), nil
+}
+
+func deleteMergeRequestDiscussionNoteErr(pid interface{}, mergeRequest int, discussion string, note int, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error) {
+	return nil, errors.New("Some error from Gitlab")
+}
+
+func deleteMergeRequestDiscussionNoteNon200(pid interface{}, mergeRequest int, discussion string, note int, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error) {
+	return makeResponse(http.StatusSeeOther), nil
+}
+
+func TestDeleteComment(t *testing.T) {
+	t.Run("Deletes a comment", func(t *testing.T) {
+		request := makeRequest(t, http.MethodDelete, "/comment", DeleteCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{deleteMergeRequestDiscussionNote: deleteMergeRequestDiscussionNote})
+		data := serveRequest(t, server, request, CommentResponse{})
+		assert(t, data.SuccessResponse.Message, "Comment deleted successfully")
+		assert(t, data.SuccessResponse.Status, http.StatusOK)
+	})
+
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodDelete, "/comment", DeleteCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{deleteMergeRequestDiscussionNote: deleteMergeRequestDiscussionNoteErr})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkErrorFromGitlab(t, *data, "Could not delete comment")
+	})
+
+	t.Run("Handles non-200s from Gitlab", func(t *testing.T) {
+		request := makeRequest(t, http.MethodDelete, "/comment", DeleteCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{deleteMergeRequestDiscussionNote: deleteMergeRequestDiscussionNoteNon200})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkNon200(t, *data, "Could not delete comment", "/comment")
+	})
+}
+
+func updateMergeRequestDiscussionNote(pid interface{}, mergeRequest int, discussion string, note int, opt *gitlab.UpdateMergeRequestDiscussionNoteOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Note, *gitlab.Response, error) {
+	return &gitlab.Note{}, makeResponse(http.StatusOK), nil
+}
+
+func updateMergeRequestDiscussionNoteErr(pid interface{}, mergeRequest int, discussion string, note int, opt *gitlab.UpdateMergeRequestDiscussionNoteOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Note, *gitlab.Response, error) {
+	return nil, nil, errors.New("Some error from Gitlab")
+}
+
+func updateMergeRequestDiscussionNoteNon200(pid interface{}, mergeRequest int, discussion string, note int, opt *gitlab.UpdateMergeRequestDiscussionNoteOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Note, *gitlab.Response, error) {
+	return nil, makeResponse(http.StatusSeeOther), nil
+}
+
+func TestEditComment(t *testing.T) {
+	t.Run("Edits a comment", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPatch, "/comment", EditCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{updateMergeRequestDiscussionNote: updateMergeRequestDiscussionNote})
+		data := serveRequest(t, server, request, CommentResponse{})
+		assert(t, data.SuccessResponse.Message, "Comment updated successfully")
+		assert(t, data.SuccessResponse.Status, http.StatusOK)
+	})
+
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPatch, "/comment", EditCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{updateMergeRequestDiscussionNote: updateMergeRequestDiscussionNoteErr})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkErrorFromGitlab(t, *data, "Could not update comment")
+	})
+
+	t.Run("Handles non-200s from Gitlab", func(t *testing.T) {
+		request := makeRequest(t, http.MethodPatch, "/comment", EditCommentRequest{})
+		server, _ := createRouterAndApi(fakeClient{updateMergeRequestDiscussionNote: updateMergeRequestDiscussionNoteNon200})
+		data := serveRequest(t, server, request, ErrorResponse{})
+		checkNon200(t, *data, "Could not update comment", "/comment")
+	})
+}