Merge pull request #532 from jakubbortlik/feat/implement-mergeability-checks

feat: add mergeability checks to summary view

cmd/app/client.go

@@ -32,6 +32,7 @@ type Client struct {
 	gitlab.UsersServiceInterface
 	gitlab.DraftNotesServiceInterface
 	gitlab.ProjectMarkdownUploadsServiceInterface
+	gitlab.GraphQLInterface
 }
 
 /* NewClient parses and validates the project settings and initializes the Gitlab client. */
@@ -100,6 +101,7 @@ func NewClient() (*Client, error) {
 		client.Users,
 		client.DraftNotes,
 		client.ProjectMarkdownUploads,
+		client.GraphQL,
 	}, nil
 }
 

cmd/app/mergeability_checks.go

@@ -0,0 +1,83 @@
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	gitlab "gitlab.com/gitlab-org/api/client-go"
+)
+
+type MergeabilityCheck struct {
+	Identifier string `json:"identifier"`
+	Status     string `json:"status"`
+}
+
+type MergeabilityChecksResponse struct {
+	SuccessResponse
+	MergeabilityChecks []*MergeabilityCheck `json:"mergeability_checks"`
+}
+
+type mergeabilityChecksGraphQLResponse struct {
+	Data struct {
+		Project struct {
+			MergeRequest struct {
+				MergeabilityChecks []*MergeabilityCheck `json:"mergeabilityChecks"`
+			} `json:"mergeRequest"`
+		} `json:"project"`
+	} `json:"data"`
+}
+
+const mergeabilityChecksQuery = `
+query GetMergeabilityChecks($projectPath: ID!, $iid: String!) {
+	project(fullPath: $projectPath) {
+		mergeRequest(iid: $iid) {
+			mergeabilityChecks {
+				identifier
+				status
+			}
+		}
+	}
+}
+`
+
+type mergeabilityChecksService struct {
+	data
+	client gitlab.GraphQLInterface
+}
+
+func (a mergeabilityChecksService) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	checks, err := a.fetchMergeabilityChecks()
+	if err != nil {
+		handleError(w, err, "Could not get mergeability checks", http.StatusInternalServerError)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	response := MergeabilityChecksResponse{
+		SuccessResponse:    SuccessResponse{Message: "Mergeability checks retrieved"},
+		MergeabilityChecks: checks,
+	}
+
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		handleError(w, err, "Could not encode response", http.StatusInternalServerError)
+	}
+}
+
+func (a mergeabilityChecksService) fetchMergeabilityChecks() ([]*MergeabilityCheck, error) {
+	var response mergeabilityChecksGraphQLResponse
+
+	_, err := a.client.Do(gitlab.GraphQLQuery{
+		Query: mergeabilityChecksQuery,
+		Variables: map[string]any{
+			"projectPath": a.gitInfo.ProjectPath(),
+			"iid":         fmt.Sprintf("%d", a.projectInfo.MergeId),
+		},
+	}, &response)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch mergeability checks: %w", err)
+	}
+
+	return response.Data.Project.MergeRequest.MergeabilityChecks, nil
+}

cmd/app/mergeability_checks_test.go

@@ -0,0 +1,121 @@
+package app
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/harrisoncramer/gitlab.nvim/cmd/app/git"
+	gitlab "gitlab.com/gitlab-org/api/client-go"
+)
+
+type fakeGraphQLClient struct {
+	err      error
+	jsonData []byte
+}
+
+func (f fakeGraphQLClient) Do(query gitlab.GraphQLQuery, response any, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error) {
+	if f.err != nil {
+		return nil, f.err
+	}
+
+	// Actually unmarshal JSON into the response struct
+	if err := json.Unmarshal(f.jsonData, response); err != nil {
+		return nil, err
+	}
+
+	// if resp, ok := response.(mergeabilityChecksGraphQLResponse); ok {
+	// 	resp.Data.Project.MergeRequest.MergeabilityChecks = f.checks
+	// }
+
+	return makeResponse(http.StatusOK), nil
+}
+
+var testMergeabilityData = data{
+	projectInfo: &ProjectInfo{MergeId: 123},
+	gitInfo: &git.GitData{
+		BranchName:  "feature-branch",
+		Namespace:   "test-namespace",
+		ProjectName: "test-project",
+	},
+}
+
+func TestMergeabilityChecksHandler(t *testing.T) {
+	t.Run("Returns mergeability checks", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/mr/mergeability_checks", nil)
+		client := fakeGraphQLClient{
+			jsonData: []byte(`{
+				"data": {
+					"project": {
+						"mergeRequest": {
+							"mergeabilityChecks": [
+								{"identifier": "CI_MUST_PASS", "status": "SUCCESS"},
+								{"identifier": "CONFLICT", "status": "FAILED"}
+							]
+						}
+					}
+				}
+			}`),
+		}
+		svc := middleware(
+			mergeabilityChecksService{testMergeabilityData, client},
+			withMethodCheck(http.MethodGet),
+		)
+
+		res := httptest.NewRecorder()
+		svc.ServeHTTP(res, request)
+
+		var data MergeabilityChecksResponse
+		err := json.Unmarshal(res.Body.Bytes(), &data)
+		assert(t, err, nil)
+
+		assert(t, data.Message, "Mergeability checks retrieved")
+		assert(t, len(data.MergeabilityChecks), 2)
+		assert(t, data.MergeabilityChecks[0].Identifier, "CI_MUST_PASS")
+		assert(t, data.MergeabilityChecks[0].Status, "SUCCESS")
+		assert(t, data.MergeabilityChecks[1].Identifier, "CONFLICT")
+		assert(t, data.MergeabilityChecks[1].Status, "FAILED")
+	})
+
+	t.Run("Returns empty list when there are no checks", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/mr/mergeability_checks", nil)
+		client := fakeGraphQLClient{
+			jsonData: []byte(`{
+				"data": {
+					"project": {
+						"mergeRequest": {
+							"mergeabilityChecks": []
+						}
+					}
+				}
+			}`),
+		}
+		svc := middleware(
+			mergeabilityChecksService{testMergeabilityData, client},
+			withMethodCheck(http.MethodGet),
+		)
+
+		res := httptest.NewRecorder()
+		svc.ServeHTTP(res, request)
+
+		var data MergeabilityChecksResponse
+		err := json.Unmarshal(res.Body.Bytes(), &data)
+		assert(t, err, nil)
+
+		assert(t, data.Message, "Mergeability checks retrieved")
+		assert(t, len(data.MergeabilityChecks), 0)
+	})
+
+	t.Run("Handles errors from Gitlab client", func(t *testing.T) {
+		request := makeRequest(t, http.MethodGet, "/mr/mergeability_checks", nil)
+		client := fakeGraphQLClient{err: errorFromGitlab}
+		svc := middleware(
+			mergeabilityChecksService{testMergeabilityData, client},
+			withMethodCheck(http.MethodGet),
+		)
+		data, _ := getFailData(t, svc, request)
+		assert(t, data.Message, "Could not get mergeability checks")
+		assert(t, data.Details, "failed to fetch mergeability checks: "+errorFromGitlab.Error())
+	})
+}

cmd/app/server.go

@@ -134,6 +134,11 @@ func CreateRouter(gitlabClient *Client, projectInfo *ProjectInfo, s *shutdownSer
 		withMr(d, gitlabClient),
 		withMethodCheck(http.MethodGet),
 	))
+	m.HandleFunc("/mr/info/mergeability", middleware(
+		mergeabilityChecksService{d, gitlabClient},
+		withMr(d, gitlabClient),
+		withMethodCheck(http.MethodGet),
+	))
 	m.HandleFunc("/mr/assignee", middleware(
 		assigneesService{d, gitlabClient},
 		withMr(d, gitlabClient),

doc/gitlab.nvim.txt

@@ -312,6 +312,39 @@ you call this function with no values the defaults will be used:
           "squash",
           "labels",
           "web_url",
+          "mergeability_checks", -- See more detailed configuration below
+        },
+        -- Settings for the mergeability checks in the summary view
+        -- https://docs.gitlab.com/api/graphql/reference/#mergeabilitycheckidentifier
+        mergeability_checks = {
+          -- Symbols for individual check statuses. Set values to `false` to hide checks with given status from summary
+          statuses = {
+            SUCCESS = "✅",
+            CHECKING = "🔁",
+            FAILED = "❌",
+            WARNING = "⚠️",
+            INACTIVE = "💤",
+          },
+          -- Descriptions for individual checks. Set values to `false` to hide given checks from summary
+          checks = {
+            CI_MUST_PASS = "Pipeline must succeed",
+            COMMITS_STATUS = "Source branch exists and contains commits",
+            CONFLICT = "Merge conflicts must be resolved",
+            DISCUSSIONS_NOT_RESOLVED = "Open threads must be resolved",
+            DRAFT_STATUS = "Merge request must not be draft",
+            JIRA_ASSOCIATION_MISSING = "Title or description references a Jira issue",
+            LOCKED_LFS_FILES = "All LFS files must be unlocked",
+            LOCKED_PATHS = "All paths must be unlocked",
+            MERGE_REQUEST_BLOCKED = "Merge request is not blocked",
+            MERGE_TIME = "Merge is not blocked due to a scheduled merge time",
+            NEED_REBASE = "Merge request must be rebased, fast-forward merge is not possible",
+            NOT_APPROVED = "All required approvals must be given",
+            NOT_OPEN = "Merge request must be open",
+            REQUESTED_CHANGES = "Change requests must be approved by the requesting user",
+            SECURITY_POLICY_VIOLATIONS = "Security policies are satisfied",
+            STATUS_CHECKS_MUST_PASS = "External status checks pass",
+            TITLE_REGEX = "Title matches the expected regex",
+          },
         },
       },
       discussion_signs = {

lua/gitlab/actions/approvals.lua

@@ -6,9 +6,11 @@ local M = {}
 
 local refresh_status_state = function(data)
   u.notify(data.message, vim.log.levels.INFO)
+  state.load_new_state("mergeability", function()
     state.load_new_state("info", function()
       require("gitlab.actions.summary").update_summary_details()
     end)
+  end)
 end
 
 M.approve = function()

lua/gitlab/actions/data.lua

@@ -6,6 +6,7 @@ local M = {}
 local user = state.dependencies.user
 local info = state.dependencies.info
 local labels = state.dependencies.labels
+local mergeability = state.dependencies.mergeability
 local project_members = state.dependencies.project_members
 local revisions = state.dependencies.revisions
 local latest_pipeline = state.dependencies.latest_pipeline
@@ -21,6 +22,7 @@ M.data = function(resources, cb)
     info = info,
     user = user,
     labels = labels,
+    mergeability = mergeability,
     project_members = project_members,
     revisions = revisions,
     pipeline = latest_pipeline,

lua/gitlab/actions/summary.lua

@@ -8,10 +8,12 @@ local job = require("gitlab.job")
 local common = require("gitlab.actions.common")
 local u = require("gitlab.utils")
 local popup = require("gitlab.popup")
-local List = require("gitlab.utils.list")
 local state = require("gitlab.state")
 local miscellaneous = require("gitlab.actions.miscellaneous")
 
+-- No-break space used in summary details to make matching different parts of the line more robust
+local nbsp = " "
+
 local M = {
   layout_visible = false,
   layout = nil,
@@ -108,6 +110,28 @@ M.update_details_popup = function(bufnr, info_lines)
   M.color_details(bufnr) -- Color values in details popup
 end
 
+---Return the mergeability checks statuses and descriptions
+---@return string[]
+local make_mergeability_checks = function()
+  local lines = {}
+  for _, check in ipairs(state.MERGEABILITY) do
+    local status = state.settings.mergeability_checks.statuses[check.status]
+    if status == nil then
+      u.notify(string.format("Unknown mergeability check status: %s", check.status), vim.log.levels.ERROR)
+    end
+    if status then
+      local description = state.settings.mergeability_checks.checks[check.identifier]
+      if description == nil then
+        u.notify(string.format("Unknown mergeability check identifier: %s", check.identifier), vim.log.levels.ERROR)
+      end
+      if description then
+        table.insert(lines, status .. " " .. description)
+      end
+    end
+  end
+  return lines
+end
+
 -- Builds a lua list of strings that contain metadata about the current MR. Only builds the
 -- lines that users include in their state.settings.info.fields list.
 M.build_info_lines = function()
@@ -132,7 +156,7 @@ M.build_info_lines = function()
     pipeline = {
       title = "Pipeline Status",
       content = function()
-        local pipeline = state.INFO.pipeline
+        local pipeline = info.head_pipeline ~= vim.NIL and info.head_pipeline or info.pipeline
         if type(pipeline) ~= "table" or (type(pipeline) == "table" and u.table_size(pipeline) == 0) then
           return ""
         end
@@ -140,6 +164,7 @@ M.build_info_lines = function()
       end,
     },
     web_url = { title = "MR URL", content = info.web_url },
+    mergeability_checks = { title = "Mergeability checks", content = make_mergeability_checks },
   }
 
   local longest_used = ""
@@ -147,33 +172,41 @@ M.build_info_lines = function()
     if v == "merge_status" then
       v = "detailed_merge_status"
     end -- merge_status was deprecated, see https://gitlab.com/gitlab-org/gitlab/-/issues/3169#note_1162532204
+    if options[v] == nil then
+      u.notify(string.format("Invalid field in settings.info.fields: '%s'", v), vim.log.levels.ERROR)
+    else
       local title = options[v].title
-    if string.len(title) > string.len(longest_used) then
+      if vim.fn.strcharlen(title) > vim.fn.strcharlen(longest_used) then
         longest_used = title
       end
     end
+  end
 
   local function row_offset(row)
-    local offset = string.len(longest_used) - string.len(row)
-    return string.rep(" ", offset + 3)
+    local offset = vim.fn.strcharlen(longest_used) - vim.fn.strcharlen(row)
+    return string.rep(nbsp, offset + 3)
   end
 
-  return List.new(state.settings.info.fields):map(function(v)
+  local result = {}
+  for _, v in ipairs(state.settings.info.fields) do
     if v == "merge_status" then
       v = "detailed_merge_status"
     end
     local row = options[v]
-    local line = "* " .. row.title .. row_offset(row.title)
-    if type(row.content) == "function" then
-      local content = row.content()
-      if content ~= nil then
-        line = line .. row.content()
+    local title_prefix = "* " .. row.title .. row_offset(row.title)
+    local content = type(row.content) == "function" and row.content() or row.content
+    if type(content) == "table" then
+      -- Multi-line content
+      local padding = string.rep(nbsp, vim.fn.strcharlen(title_prefix)) -- no-break space
+      for i, line in ipairs(#content > 0 and content or { "" }) do
+        table.insert(result, (i == 1 and title_prefix or padding) .. line)
       end
     else
-      line = line .. row.content
+      -- Single-line content
+      table.insert(result, title_prefix .. (content or ""))
     end
-    return line
-  end)
+  end
+  return result
 end
 
 -- This function will PUT the new description to the Go server
@@ -260,24 +293,57 @@ end
 
 M.color_details = function(bufnr)
   local details_namespace = vim.api.nvim_create_namespace("Details")
-  for i, v in ipairs(state.settings.info.fields) do
-    if v == "labels" then
-      local line_content = u.get_line_content(bufnr, i)
+  for i, line in ipairs(vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)) do
+    if line:match("^* Labels") then
       for j, label in ipairs(state.LABELS) do
-        local start_idx, end_idx = line_content:find(label.Name)
+        local start_idx, end_idx = line:find(label.Name, 1, true)
         if start_idx ~= nil and end_idx ~= nil then
           vim.cmd("highlight " .. "label" .. j .. " guifg=white")
           vim.api.nvim_set_hl(0, ("label" .. j), { fg = label.Color })
-          vim.api.nvim_buf_add_highlight(bufnr, details_namespace, ("label" .. j), i - 1, start_idx - 1, end_idx)
+          vim.hl.range(bufnr, details_namespace, ("label" .. j), { i - 1, start_idx - 1 }, { i - 1, end_idx })
         end
       end
-    elseif v == "delete_branch" or v == "squash" or v == "draft" or v == "conflicts" then
-      local line_content = u.get_line_content(bufnr, i)
-      local start_idx, end_idx = line_content:find("%S-$")
-      if start_idx ~= nil and end_idx ~= nil then
+    elseif line:match("^* Status") then
+      local status = line:match("[^" .. nbsp .. "]-$")
+      local hl = ({
+        blocked_status = "DiagnosticError",
+        broken_status = "DiagnosticError",
+        checking = "DiagnosticInfo",
+        ci_must_pass = "DiagnosticWarn",
+        ci_still_running = "DiagnosticInfo",
+        discussions_not_resolved = "DiagnosticWarn",
+        draft_status = "Comment",
+        external_status_checks = "DiagnosticHint",
+        mergeable = "DiagnosticOK",
+        not_approved = "DiagnosticWarn",
+        not_open = "NonText",
+        policies_denied = "DiagnosticError",
+        unchecked = "NonText",
+      })[status] or "Normal"
+      local start_idx, end_idx = line:find("[^" .. nbsp .. "]-$")
+      vim.hl.range(bufnr, details_namespace, hl, { i - 1, start_idx - 1 }, { i - 1, end_idx })
+    elseif line:match("^* Branch") or line:match("^* Target Branch") then
+      local start_idx, end_idx = line:find("[^" .. nbsp .. "]-$")
+      vim.hl.range(bufnr, details_namespace, "Title", { i - 1, start_idx - 1 }, { i - 1, end_idx })
+    elseif line:match("^* Pipeline") then
+      local status = line:match("[^" .. nbsp .. "]-$")
+      local hl = ({
+        canceled = "DiagnosticWarn",
+        created = "DiagnosticInfo",
+        failed = "DiagnosticError",
+        manual = "DiagnosticHint",
+        pending = "DiagnosticWarn",
+        running = "DiagnosticInfo",
+        skipped = "Comment",
+        success = "DiagnosticOK",
+        unknown = "NonText",
+      })[status] or "Normal"
+      local start_idx, end_idx = line:find("[^" .. nbsp .. "]-$")
+      vim.hl.range(bufnr, details_namespace, hl, { i - 1, start_idx - 1 }, { i - 1, end_idx })
+    elseif line:match(nbsp .. "No$") or line:match(nbsp .. "Yes$") then
+      local start_idx, end_idx = line:find("[^" .. nbsp .. "]-$")
       vim.api.nvim_set_hl(0, "boolean", { link = "Constant" })
-        vim.api.nvim_buf_add_highlight(bufnr, details_namespace, "boolean", i - 1, start_idx - 1, end_idx)
-      end
+      vim.hl.range(bufnr, details_namespace, "boolean", { i - 1, start_idx - 1 }, { i - 1, end_idx })
     end
   end
 end

lua/gitlab/annotations.lua

@@ -159,6 +159,7 @@
 ---@field discussion_tree? DiscussionSettings -- Settings for the popup windows
 ---@field choose_merge_request? ChooseMergeRequestSettings -- Default settings when choosing a merge request
 ---@field info? InfoSettings -- Settings for the "info" or "summary" view
+---@field mergeability_checks? MergeabilityChecksSettings -- Settings for the mergeability checks in the "summary" view
 ---@field discussion_signs? DiscussionSigns -- The settings for discussion signs/diagnostics
 ---@field pipeline? PipelineSettings -- The settings for the pipeline popup
 ---@field create_mr? CreateMrSettings -- The settings when creating an MR
@@ -252,7 +253,37 @@
 
 ---@class InfoSettings
 ---@field horizontal? boolean -- Display metadata to the left of the summary rather than underneath
----@field fields? ("author" | "created_at" | "updated_at" | "merge_status" | "draft" | "conflicts" | "assignees" | "reviewers" | "pipeline" | "branch" | "target_branch" | "delete_branch" | "squash" | "labels")[]
+---@field fields? ("author" | "created_at" | "updated_at" | "merge_status" | "draft" | "conflicts" | "assignees" | "reviewers" | "pipeline" | "branch" | "target_branch" | "delete_branch" | "squash" | "labels" | "web_url" | "mergeability_checks")[]
+
+---@class MergeabilityChecksSettings
+---@field statuses MergeabilityStatuses
+---@field checks MergeabilityChecks
+
+---@class MergeabilityStatuses
+---@field SUCCESS string|false
+---@field CHECKING string|false
+---@field FAILED string|false
+---@field WARNING string|false
+---@field INACTIVE string|false
+
+---@class MergeabilityChecks
+---@field CI_MUST_PASS string|false
+---@field COMMITS_STATUS string|false
+---@field CONFLICT string|false
+---@field DISCUSSIONS_NOT_RESOLVED string|false
+---@field DRAFT_STATUS string|false
+---@field JIRA_ASSOCIATION_MISSING string|false
+---@field LOCKED_LFS_FILES string|false
+---@field LOCKED_PATHS string|false
+---@field MERGE_REQUEST_BLOCKED string|false
+---@field MERGE_TIME string|false
+---@field NEED_REBASE string|false
+---@field NOT_APPROVED string|false
+---@field NOT_OPEN string|false
+---@field REQUESTED_CHANGES string|false
+---@field SECURITY_POLICY_VIOLATIONS string|false
+---@field STATUS_CHECKS_MUST_PASS string|false
+---@field TITLE_REGEX string|false
 
 ---@class DiscussionSettings: table
 ---@field expanders? ExpanderOpts -- Customize the expander icons in the discussion tree

lua/gitlab/init.lua

@@ -22,6 +22,7 @@ local health = require("gitlab.health")
 
 local user = state.dependencies.user
 local info = state.dependencies.info
+local mergeability = state.dependencies.mergeability
 local labels_dep = state.dependencies.labels
 local project_members = state.dependencies.project_members
 local latest_pipeline = state.dependencies.latest_pipeline
@@ -62,6 +63,7 @@ return {
   setup = setup,
   summary = async.sequence({
     u.merge(info, { refresh = true }),
+    u.merge(mergeability, { refresh = true }),
     labels_dep,
   }, summary.summary),
   approve = async.sequence({ info }, approvals.approve),

lua/gitlab/state.lua

@@ -218,6 +218,35 @@ M.settings = {
       "squash",
       "labels",
       "web_url",
+      "mergeability_checks",
+    },
+  },
+  mergeability_checks = {
+    statuses = {
+      SUCCESS = "✅",
+      CHECKING = "🔁",
+      FAILED = "❌",
+      WARNING = "⚠️",
+      INACTIVE = "💤",
+    },
+    checks = {
+      CI_MUST_PASS = "Pipeline must succeed",
+      COMMITS_STATUS = "Source branch exists and contains commits",
+      CONFLICT = "Merge conflicts must be resolved",
+      DISCUSSIONS_NOT_RESOLVED = "Open threads must be resolved",
+      DRAFT_STATUS = "Merge request must not be draft",
+      JIRA_ASSOCIATION_MISSING = "Title or description references a Jira issue",
+      LOCKED_LFS_FILES = "All LFS files must be unlocked",
+      LOCKED_PATHS = "All paths must be unlocked",
+      MERGE_REQUEST_BLOCKED = "Merge request is not blocked",
+      MERGE_TIME = "Merge is not blocked due to a scheduled merge time",
+      NEED_REBASE = "Merge request must be rebased, fast-forward merge is not possible",
+      NOT_APPROVED = "All required approvals must be given",
+      NOT_OPEN = "Merge request must be open",
+      REQUESTED_CHANGES = "Change requests must be approved by the requesting user",
+      SECURITY_POLICY_VIOLATIONS = "Security policies are satisfied",
+      STATUS_CHECKS_MUST_PASS = "External status checks pass",
+      TITLE_REGEX = "Title matches the expected regex",
     },
   },
   discussion_signs = {
@@ -467,6 +496,12 @@ M.dependencies = {
     state = "INFO",
     refresh = false,
   },
+  mergeability = {
+    endpoint = "/mr/info/mergeability",
+    key = "mergeability_checks",
+    state = "MERGEABILITY",
+    refresh = false,
+  },
   latest_pipeline = {
     endpoint = "/pipeline",
     key = "latest_pipeline",

lua/gitlab/utils/init.lua

@@ -309,8 +309,8 @@ end
 M.get_longest_string = function(list)
   local longest = 0
   for _, v in pairs(list) do
-    if string.len(v) > longest then
-      longest = string.len(v)
+    if vim.fn.strcharlen(v) > longest then
+      longest = vim.fn.strcharlen(v)
     end
   end
   return longest