diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 37aba38..878d343 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1,6 +1,7 @@
 " Tests for various functions.
 source shared.vim
 source check.vim
+source term_util.vim
 
 " Must be done first, since the alternate buffer must be unset.
 func Test_00_bufexists()
@@ -1659,3 +1660,62 @@
   call assert_equal(0, bufexists('someName'))
   call delete('XotherName')
 endfunc
+
+func Test_state()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+	call setline(1, ['one', 'two', 'three'])
+	map ;; gg
+	func RunTimer()
+	  call timer_start(10, {id -> execute('let g:state = state()') .. execute('let g:mode = mode()')})
+	endfunc
+	au Filetype foobar let g:state = state()|let g:mode = mode()
+  END
+  call writefile(lines, 'XState')
+  let buf = RunVimInTerminal('-S XState', #{rows: 6})
+
+  " Using a ":" command Vim is busy, thus "S" is returned
+  call term_sendkeys(buf, ":echo 'state: ' .. state() .. '; mode: ' .. mode()\<CR>")
+  call WaitForAssert({-> assert_match('state: S; mode: n', term_getline(buf, 6))}, 1000)
+  call term_sendkeys(buf, ":\<CR>")
+
+  " Using a timer callback
+  call term_sendkeys(buf, ":call RunTimer()\<CR>")
+  call term_wait(buf, 50)
+  let getstate = ":echo 'state: ' .. g:state .. '; mode: ' .. g:mode\<CR>"
+  call term_sendkeys(buf, getstate)
+  call WaitForAssert({-> assert_match('state: c; mode: n', term_getline(buf, 6))}, 1000)
+
+  " Halfway a mapping
+  call term_sendkeys(buf, ":call RunTimer()\<CR>;")
+  call term_wait(buf, 50)
+  call term_sendkeys(buf, ";")
+  call term_sendkeys(buf, getstate)
+  call WaitForAssert({-> assert_match('state: mSc; mode: n', term_getline(buf, 6))}, 1000)
+
+  " Insert mode completion
+  call term_sendkeys(buf, ":call RunTimer()\<CR>Got\<C-N>")
+  call term_wait(buf, 50)
+  call term_sendkeys(buf, "\<Esc>")
+  call term_sendkeys(buf, getstate)
+  call WaitForAssert({-> assert_match('state: aSc; mode: i', term_getline(buf, 6))}, 1000)
+
+  " Autocommand executing
+  call term_sendkeys(buf, ":set filetype=foobar\<CR>")
+  call term_wait(buf, 50)
+  call term_sendkeys(buf, getstate)
+  call WaitForAssert({-> assert_match('state: xS; mode: n', term_getline(buf, 6))}, 1000)
+
+  " Todo: "w" - waiting for ch_evalexpr()
+
+  " messages scrolled
+  call term_sendkeys(buf, ":call RunTimer()\<CR>:echo \"one\\ntwo\\nthree\"\<CR>")
+  call term_wait(buf, 50)
+  call term_sendkeys(buf, "\<CR>")
+  call term_sendkeys(buf, getstate)
+  call WaitForAssert({-> assert_match('state: Scs; mode: r', term_getline(buf, 6))}, 1000)
+
+  call StopVimInTerminal(buf)
+  call delete('XState')
+endfunc