TST: some tex tests also need to guard against missing gs

jankatins · matthew-brett · commit 890c5aded195 · 2016-08-24T20:36:58.000-07:00
Also fixed a problem in an error message when bytes were appended to
a string (fails on py3.x) by using %.

One of the errors before:

======================================================================
ERROR: matplotlib.tests.test_backend_ps.test_savefig_to_stringio_with_usetex
----------------------------------------------------------------------
Traceback (most recent call last):
  File "lib\site-packages\nose\case.py", line 198, in runTest
    self.test(*self.arg)
  File "lib\matplotlib\testing\decorators.py", line 152, in wrapped_callable

    func(*args, **kwargs)
  File "lib\matplotlib\testing\decorators.py", line 55, in failer
    result = f(*args, **kwargs)
  File "lib\matplotlib\tests\test_backend_ps.py", line 77, in test_savefig_to_stringio_with_usetex
    _test_savefig_to_stringio()
  File "lib\matplotlib\tests\test_backend_ps.py", line 40, in _test_savefig_to_stringio
    fig.savefig(buffer, format=format)
  File "lib\matplotlib\figure.py", line 1698, in savefig
    self.canvas.print_figure(*args, **kwargs)
  File "lib\matplotlib\backend_bases.py", line 2232, in print_figure
    **kwargs)
  File "lib\matplotlib\backends\backend_ps.py", line 985, in print_ps
    return self._print_ps(outfile, 'ps', *args, **kwargs)
  File "lib\matplotlib\backends\backend_ps.py", line 1012, in _print_ps
    **kwargs)
  File "lib\matplotlib\backends\backend_ps.py", line 1376, in _print_figure_tex
    rotated=psfrag_rotated)
  File "lib\matplotlib\backends\backend_ps.py", line 1539, in gs_distill
    raise RuntimeError(m % output)
RuntimeError: ghostscript was not able to process your image.
Here is the full report generated by ghostscript:

b''
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -1503,8 +1503,13 @@ def gs_distill(tmpfile, eps=False, ptype='letter', bbox=None, rotated=False):
 
     with io.open(outfile, 'rb') as fh:
         if exit_status:
-            raise RuntimeError('ghostscript was not able to process \
-    your image.\nHere is the full report generated by ghostscript:\n\n' + fh.read())
+            output = fh.read()
+            m = "\n".join(["ghostscript was not able to process your image.",
+                           "Here is the full report generated by ghostscript:",
+                           "",
+                           "%s"])
+            # use % to prevent problems with bytes
+            raise RuntimeError(m % output)
         else:
             verbose.report(fh.read(), 'debug')
     os.remove(outfile)
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
@@ -71,6 +71,7 @@ def test_savefig_to_stringio_with_distiller():
 
 @cleanup
 @needs_tex
+@needs_ghostscript
 def test_savefig_to_stringio_with_usetex():
     matplotlib.rcParams['text.latex.unicode'] = True
     matplotlib.rcParams['text.usetex'] = True
@@ -90,6 +91,7 @@ def test_savefig_to_stringio_eps_afm():
 
 @cleanup
 @needs_tex
+@needs_ghostscript
 def test_savefig_to_stringio_with_usetex_eps():
     matplotlib.rcParams['text.latex.unicode'] = True
     matplotlib.rcParams['text.usetex'] = True
