api: vim_err_write: add tests for multiline handling

test/functional/api/vim_spec.lua

@@ -1,6 +1,8 @@
 -- Sanity checks for vim_* API calls via msgpack-rpc
 local helpers = require('test.functional.helpers')
-local clear, nvim, eq, neq, ok = helpers.clear, helpers.nvim, helpers.eq, helpers.neq, helpers.ok
+local Screen = require('test.functional.ui.screen')
+local clear, nvim, eq, neq = helpers.clear, helpers.nvim, helpers.eq, helpers.neq
+local ok, nvim_async, feed = helpers.ok, helpers.nvim_async, helpers.feed
 
 
 describe('vim_* functions', function()
@@ -177,6 +179,104 @@ describe('vim_* functions', function()
     end)
   end)
 
+  describe('err_write', function()
+    before_each(function()
+      clear()
+      screen = Screen.new(40, 8)
+      screen:attach()
+      screen:set_default_attr_ids({
+        [1] = {foreground = Screen.colors.White, background = Screen.colors.Red},
+        [2] = {bold = true, foreground = Screen.colors.SeaGreen}
+      })
+      screen:set_default_attr_ignore( {{bold=true, foreground=Screen.colors.Blue}} )
+    end)
+
+    it('can show one line', function()
+      nvim_async('err_write', 'has bork\n')
+      screen:expect([[
+        ^                                        |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:has bork}                                |
+      ]])
+    end)
+
+    it('shows return prompt when more than &cmdheight lines', function()
+      nvim_async('err_write', 'something happened\nvery bad\n')
+      screen:expect([[
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:something happened}                      |
+        {1:very bad}                                |
+        {2:Press ENTER or type command to continue}^ |
+      ]])
+    end)
+
+    it('shows return prompt after all lines are shown', function()
+      nvim_async('err_write', 'FAILURE\nERROR\nEXCEPTION\nTRACEBACK\n')
+      screen:expect([[
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:FAILURE}                                 |
+        {1:ERROR}                                   |
+        {1:EXCEPTION}                               |
+        {1:TRACEBACK}                               |
+        {2:Press ENTER or type command to continue}^ |
+      ]])
+    end)
+
+    it('handles multiple calls', function()
+      -- without linebreak text is joined to one line
+      nvim_async('err_write', 'very ')
+      nvim_async('err_write', 'fail\n')
+      screen:expect([[
+        ^                                        |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:very fail}                               |
+      ]])
+
+      -- shows up to &cmdheight lines
+      nvim_async('err_write', 'more fail\n')
+      nvim_async('err_write', 'too fail\n')
+      screen:expect([[
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:very fail}                               |
+        {1:more fail}                               |
+        {2:Press ENTER or type command to continue}^ |
+      ]])
+
+      -- shows the rest after return
+      feed('<cr>')
+      screen:expect([[
+        ~                                       |
+        ~                                       |
+        ~                                       |
+        {1:very fail}                               |
+        {1:more fail}                               |
+        {2:Press ENTER or type command to continue} |
+        {1:too fail}                                |
+        {2:Press ENTER or type command to continue}^ |
+      ]])
+    end)
+  end)
+
   it('can throw exceptions', function()
     local status, err = pcall(nvim, 'get_option', 'invalid-option')
     eq(false, status)

test/functional/helpers.lua

@@ -246,6 +246,10 @@ local function nvim(method, ...)
   return request('vim_'..method, ...)
 end
 
+local function nvim_async(method, ...)
+  session:notify('vim_'..method, ...)
+end
+
 local function buffer(method, ...)
   return request('buffer_'..method, ...)
 end
@@ -341,6 +345,7 @@ return {
   expect = expect,
   ok = ok,
   nvim = nvim,
+  nvim_async = nvim_async,
   nvim_prog = nvim_prog,
   nvim_dir = nvim_dir,
   buffer = buffer,

test/functional/ui/screen.lua

@@ -489,7 +489,7 @@ function Screen:snapshot_util(attrs, ignore)
   self:print_snapshot(attrs, ignore)
 end
 
-function Screen:redraw_debug(attrs, ignore)
+function Screen:redraw_debug(attrs, ignore, timeout)
   self:print_snapshot(attrs, ignore)
   local function notification_cb(method, args)
     assert(method == 'redraw')
@@ -500,7 +500,10 @@ function Screen:redraw_debug(attrs, ignore)
     self:print_snapshot(attrs, ignore)
     return true
   end
-  run(nil, notification_cb, nil, 250)
+  if timeout == nil then
+    timeout = 250
+  end
+  run(nil, notification_cb, nil, timeout)
 end
 
 function Screen:print_snapshot(attrs, ignore)