1 files changed, 123 insertions, 0 deletions
diff --git a/src/testdir/screendump.vim b/src/testdir/screendump.vim
new file mode 100644
index 0000000..a2a54f4
--- /dev/null
+++ b/src/testdir/screendump.vim
@@ -0,0 +1,123 @@
+" Functions shared by tests making screen dumps.
+
+" Only load this script once.
+if exists('*VerifyScreenDump')
+  finish
+endif
+
+source shared.vim
+source term_util.vim
+
+" Skip the rest if there is no terminal feature at all.
+if !has('terminal')
+  finish
+endif
+
+" Read a dump file "fname" and if "filter" exists apply it to the text.
+def ReadAndFilter(fname: string, filter: string): list<string>
+  var contents = readfile(fname)
+
+  if filereadable(filter)
+    # do this in the bottom window so that the terminal window is unaffected
+    wincmd j
+    enew
+    setline(1, contents)
+    exe "source " .. filter
+    contents = getline(1, '$')
+    enew!
+    wincmd k
+    redraw
+  endif
+
+  return contents
+enddef
+
+
+" Verify that Vim running in terminal buffer "buf" matches the screen dump.
+" "options" is passed to term_dumpwrite().
+" Additionally, the "wait" entry can specify the maximum time to wait for the
+" screen dump to match in msec (default 1000 msec).
+" The file name used is "dumps/{filename}.dump".
+"
+" To ignore part of the dump, provide a "dumps/{filename}.vim" file with
+" Vim commands to be applied to both the reference and the current dump, so
+" that parts that are irrelevant are not used for the comparison.  The result
+" is NOT written, thus "term_dumpdiff()" shows the difference anyway.
+"
+" Optionally an extra argument can be passed which is prepended to the error
+" message.  Use this when using the same dump file with different options.
+" Returns non-zero when verification fails.
+func VerifyScreenDump(buf, filename, options, ...)
+  let reference = 'dumps/' . a:filename . '.dump'
+  let filter = 'dumps/' . a:filename . '.vim'
+  let testfile = 'failed/' . a:filename . '.dump'
+
+  let max_loops = get(a:options, 'wait', 1000) / 10
+
+  " Starting a terminal to make a screendump is always considered flaky.
+  let g:test_is_flaky = 1
+
+  " wait for the pending updates to be handled.
+  call TermWait(a:buf)
+
+  " Redraw to execute the code that updates the screen.  Otherwise we get the
+  " text and attributes only from the internal buffer.
+  redraw
+
+  if filereadable(reference)
+    let refdump = ReadAndFilter(reference, filter)
+  else
+    " Must be a new screendump, always fail
+    let refdump = []
+  endif
+
+  let did_mkdir = 0
+  if !isdirectory('failed')
+    let did_mkdir = 1
+    call mkdir('failed')
+  endif
+
+  let i = 0
+  while 1
+    " leave some time for updating the original window
+    sleep 10m
+    call delete(testfile)
+    call term_dumpwrite(a:buf, testfile, a:options)
+    let testdump = ReadAndFilter(testfile, filter)
+    if refdump == testdump
+      call delete(testfile)
+      if did_mkdir
+	call delete('failed', 'd')
+      endif
+      break
+    endif
+    if i == max_loops
+      " Leave the failed dump around for inspection.
+      if filereadable(reference)
+	let msg = 'See dump file difference: call term_dumpdiff("testdir/' .. testfile .. '", "testdir/' .. reference .. '")'
+	if a:0 == 1
+	  let msg = a:1 . ': ' . msg
+	endif
+	if len(testdump) != len(refdump)
+	  let msg = msg . '; line count is ' . len(testdump) . ' instead of ' . len(refdump)
+	endif
+      else
+	let msg = 'See new dump file: call term_dumpload("testdir/' .. testfile .. '")'
+	" no point in retrying
+	let g:run_nr = 10
+      endif
+      for i in range(len(refdump))
+	if i >= len(testdump)
+	  break
+	endif
+	if testdump[i] != refdump[i]
+	  let msg = msg . '; difference in line ' . (i + 1) . ': "' . testdump[i] . '"'
+	endif
+      endfor
+      call assert_report(msg)
+      return 1
+    endif
+    let i += 1
+  endwhile
+  return 0
+endfunc