test: wait for changedtick before asserting buffer changes (#1857)

Author: pynappo

tests/neo-tree/ui/icons_spec.lua

@@ -2,6 +2,7 @@ pcall(require, "luacov")
 
 local ns_id = require("neo-tree.ui.highlights").ns_id
 local u = require("tests.utils")
+local events = require("neo-tree.events")
 
 describe("ui/icons", function()
   local req_switch = u.get_require_switch()
@@ -61,13 +62,13 @@ describe("ui/icons", function()
         "   * 1.md",
       })
 
+      local wait = u.changedtick_waiter(bufnr, 2)
       vim.api.nvim_win_set_cursor(winid, { 2, 0 })
       u.feedkeys("<CR>")
 
       vim.api.nvim_win_set_cursor(winid, { 3, 0 })
       u.feedkeys("<CR>")
-
-      vim.wait(100)
+      wait()
 
       u.assert_buf_lines(bufnr, {
         string.format("  %s", fs_tree.abspath):sub(1, 42),
@@ -98,13 +99,13 @@ describe("ui/icons", function()
         "    1.md",
       })
 
+      local wait = u.changedtick_waiter(bufnr, 4)
       vim.api.nvim_win_set_cursor(winid, { 2, 0 })
       u.feedkeys("<CR>")
 
       vim.api.nvim_win_set_cursor(winid, { 3, 0 })
       u.feedkeys("<CR>")
-
-      vim.wait(100)
+      wait()
 
       u.assert_buf_lines(bufnr, {
         vim.fn.strcharpart(string.format("  %s", fs_tree.abspath), 0, 40),
@@ -159,13 +160,13 @@ describe("ui/icons", function()
         "   f 1.md",
       })
 
+      local wait = u.changedtick_waiter(bufnr, 4)
       vim.api.nvim_win_set_cursor(winid, { 2, 0 })
       u.feedkeys("<CR>")
 
       vim.api.nvim_win_set_cursor(winid, { 3, 0 })
       u.feedkeys("<CR>")
-
-      vim.wait(100)
+      wait()
 
       u.assert_buf_lines(bufnr, {
         string.format(" o %s", fs_tree.abspath):sub(1, 40),
@@ -196,13 +197,13 @@ describe("ui/icons", function()
         "    1.md",
       })
 
+      local wait = u.changedtick_waiter(bufnr, 4)
       vim.api.nvim_win_set_cursor(winid, { 2, 0 })
       u.feedkeys("<CR>")
 
       vim.api.nvim_win_set_cursor(winid, { 3, 0 })
       u.feedkeys("<CR>")
-
-      vim.wait(100)
+      wait()
 
       u.assert_buf_lines(bufnr, {
         vim.fn.strcharpart(string.format(" o %s", fs_tree.abspath), 0, 40),

tests/utils/init.lua

@@ -1,6 +1,7 @@
 local mod = {
   fs = require("tests.utils.fs"),
 }
+local events = require("neo-tree.events")
 
 function mod.clear_environment()
   -- Create fresh window
@@ -188,4 +189,27 @@ function mod.wait_for_neo_tree(options)
   end, options)
 end
 
+function mod.changedtick_waiter(bufnr, offset_goal, timeout)
+  local changedtick = vim.b[bufnr].changedtick
+  timeout = timeout or 4000
+  return function()
+    assert(
+      vim.wait(timeout, function()
+        local offset = vim.b[bufnr].changedtick - changedtick
+        return offset >= offset_goal
+      end),
+      ("expected changedtick offset of %s or more, got %s - %s. lines: %s"):format(
+        offset_goal,
+        vim.b[bufnr].changedtick,
+        changedtick,
+        table.concat(mod.buflines(bufnr), "\n")
+      )
+    )
+  end
+end
+
+function mod.buflines(bufnr)
+  return vim.api.nvim_buf_get_lines(bufnr, 0, -1, false)
+end
+
 return mod