diff --git a/src/testdir/test_gui.vim b/src/testdir/test_gui.vim
index 8817d8f2c..506a80095 100644
--- a/src/testdir/test_gui.vim
+++ b/src/testdir/test_gui.vim
@@ -22,6 +22,15 @@ func Test_1_set_secure()
   call assert_equal(1, has('gui_running'))
 endfunc
 
+" As for non-GUI, a balloon_show() test was already added through the patch
+" 8.0.0401 (a0107bdf87).
+func Test_balloon_show()
+  if has('balloon_eval')
+    " This won't do anything but must not crash either.
+    call balloon_show('hi!')
+  endif
+endfunc
+
 func Test_getfontname_with_arg()
   let skipped = ''
 
@@ -117,6 +126,146 @@ func Test_quoteplus()
   endif
 endfunc
 
+func Test_set_balloondelay()
+  let skipped = ''
+
+  if !exists('+balloondelay')
+    let skipped = g:not_supported . 'balloondelay'
+  else
+    let balloondelay_saved = &balloondelay
+
+    " Check if the default value is identical to that described in the manual.
+    set balloondelay&
+    call assert_equal(600, &balloondelay)
+
+    " Edge cases
+
+    " XXX This fact should be hidden so that people won't be tempted to write
+    " plugin/TimeMachine.vim.  TODO Add reasonable range checks to the source
+    " code.
+    set balloondelay=-1
+    call assert_equal(-1, &balloondelay)
+
+    " Though it's possible to interpret the zero delay to be 'as soon as
+    " possible' or even 'indefinite', its actual meaning depends on the GUI
+    " toolkit in use after all.
+    set balloondelay=0
+    call assert_equal(0, &balloondelay)
+
+    set balloondelay=1
+    call assert_equal(1, &balloondelay)
+
+    " Since p_bdelay is of type long currently, the upper bound can be
+    " impractically huge and machine-dependent.  Practically, it's sufficient
+    " to check if balloondelay works with 0xffffffff (32 bits) for now.
+    set balloondelay=4294967295
+    call assert_equal(4294967295, &balloondelay)
+
+    let &balloondelay = balloondelay_saved
+  endif
+
+  if !empty(skipped)
+    throw skipped
+  endif
+endfunc
+
+func Test_set_ballooneval()
+  let skipped = ''
+
+  if !exists('+ballooneval')
+    let skipped = g:not_supported . 'ballooneval'
+  else
+    let ballooneval_saved = &ballooneval
+
+    set ballooneval&
+    call assert_equal(0, &ballooneval)
+
+    set ballooneval
+    call assert_notequal(0, &ballooneval)
+
+    set noballooneval
+    call assert_equal(0, &ballooneval)
+
+    let &ballooneval = ballooneval_saved
+  endif
+
+  if !empty(skipped)
+    throw skipped
+  endif
+endfunc
+
+func Test_set_balloonexpr()
+  let skipped = ''
+
+  if !exists('+balloonexpr')
+  else
+    let balloonexpr_saved = &balloonexpr
+
+    " Default value
+    set balloonexpr&
+    call assert_equal('', &balloonexpr)
+
+    " User-defined function
+    new
+    func MyBalloonExpr()
+        return 'Cursor is at line ' . v:beval_lnum .
+                \', column ' . v:beval_col .
+                \ ' of file ' .  bufname(v:beval_bufnr) .
+                \ ' on word "' . v:beval_text . '"' .
+                \ ' in window ' . v:beval_winid . ' (#' . v:beval_winnr . ')'
+    endfunc
+    setl balloonexpr=MyBalloonExpr()
+    setl ballooneval
+    call assert_equal('MyBalloonExpr()', &balloonexpr)
+    " TODO Read non-empty text, place the pointer at a character of a word,
+    " and check if the content of the balloon is the smae as what is expected.
+    " Also, check if textlock works as expected.
+    setl balloonexpr&
+    call assert_equal('', &balloonexpr)
+    delfunc MyBalloonExpr
+    bwipe!
+
+    " Multiline support
+    if has('balloon_multiline')
+      " Multiline balloon using NL
+      new
+      func MyBalloonFuncForMultilineUsingNL()
+        return "Multiline\nSuppported\nBalloon\nusing NL"
+      endfunc
+      setl balloonexpr=MyBalloonFuncForMultilineUsingNL()
+      setl ballooneval
+      call assert_equal('MyBalloonFuncForMultilineUsingNL()', &balloonexpr)
+      " TODO Read non-empty text, place the pointer at a character of a word,
+      " and check if the content of the balloon is the smae as what is
+      " expected.  Also, check if textlock works as expected.
+      setl balloonexpr&
+      delfunc MyBalloonFuncForMultilineUsingNL
+      bwipe!
+
+      " Multiline balloon using List
+      new
+      func MyBalloonFuncForMultilineUsingList()
+        return [ 'Multiline', 'Suppported', 'Balloon', 'using List' ]
+      endfunc
+      setl balloonexpr=MyBalloonFuncForMultilineUsingList()
+      setl ballooneval
+      call assert_equal('MyBalloonFuncForMultilineUsingList()', &balloonexpr)
+      " TODO Read non-empty text, place the pointer at a character of a word,
+      " and check if the content of the balloon is the smae as what is
+      " expected.  Also, check if textlock works as expected.
+      setl balloonexpr&
+      delfunc MyBalloonFuncForMultilineUsingList
+      bwipe!
+    endif
+
+    let &balloonexpr = balloonexpr_saved
+  endif
+
+  if !empty(skipped)
+    throw skipped
+  endif
+endfunc
+
 func Test_set_guifont()
   let skipped = ''