Add CheckNotMacVim command for tests

src/testdir/check.vim

@@ -111,6 +111,14 @@ func CheckNotBSD()
   endif
 endfunc
 
+" Command to check for not running on a MacVim.
+command CheckNotMacVim call CheckNotMacVim()
+func CheckNotMacVim()
+  if has('gui_macvim')
+    throw 'Skipped: does not work on MacVim'
+  endif
+endfunc
+
 " Command to check that making screendumps is supported.
 " Caller must source screendump.vim
 command CheckScreendump call CheckScreendump()

src/testdir/test_clientserver.vim

@@ -9,10 +9,10 @@ endif
 
 CheckFeature clientserver
 
-if has('gui_macvim') && !has('gui_running')
+if has('gui_macvim')
   " MacVim currently doesn't support client_server for non-gui.
   " See https://github.com/macvim-dev/macvim/issues/657
-  finish
+  CheckGui
 endif
 
 source shared.vim

src/testdir/test_edit.vim

@@ -1209,8 +1209,8 @@ endfunc
 
 func Test_edit_MOUSE()
   " This is a simple test, since we not really using the mouse here
-  if (has("gui_macvim") && has("gui_running"))
-    return
+  if has("gui_macvim")
+    CheckNotGui
   endif
   CheckFeature mouse
   10new

src/testdir/test_startup.vim

@@ -839,7 +839,7 @@ func Test_v_argv()
   let out = system(GetVimCommand() . ' -es -V1 -X arg1 --cmd "echo v:argv" --cmd q')
   let list = out->split("', '")
   if !has('gui_macvim') " MacVim doesn't always use 'vim' as the executable as it could be 'Vim'
-      call assert_match('vim', list[0])
+    call assert_match('vim', list[0])
   endif
   let idx = index(list, 'arg1')
   call assert_true(idx > 2)