Add dependency on ucs for pgf tests using [utf8x]{inputenc}.

anntzer · anntzer · commit 3b9102c58731 · 2020-11-02T17:26:35.000+01:00
`ucs` is a dependency of `\usepackage[utf8x]{inputenc}`, but if it
is absent we fail later with the slightly confusing error message
"Keyboard character used is undefined in inputencoding `utf8x'" (as
can be observed by temporarily uninstalling `ucs`).  Instead, make
the dependency explicit.  Also, in test_rcupdate, only one of the two
iterations uses `[utf8x]{inputenc}`, so run the other iteration first
(giving it a chance to fail) and skip the test only at the second
iteration if needed.
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
@@ -46,9 +46,9 @@ def check_for(texsystem):
                                     reason='lualatex + pgf is required')
 
 
-def _has_sfmath():
+def _has_tex_package(package):
     return (shutil.which("kpsewhich")
-            and subprocess.run(["kpsewhich", "sfmath.sty"],
+            and subprocess.run(["kpsewhich", f"{package}.sty"],
                                stdout=subprocess.PIPE).returncode == 0)
 
 
@@ -113,6 +113,7 @@ def test_xelatex():
 
 # test compiling a figure to pdf with pdflatex
 @needs_pdflatex
+@pytest.mark.skipif(not _has_tex_package('ucs'), reason='needs ucs.sty')
 @pytest.mark.backend('pgf')
 @image_comparison(['pgf_pdflatex.pdf'], style='default')
 def test_pdflatex():
@@ -132,7 +133,6 @@ def test_pdflatex():
 # test updating the rc parameters for each figure
 @needs_xelatex
 @needs_pdflatex
-@pytest.mark.skipif(not _has_sfmath(), reason='needs sfmath.sty')
 @pytest.mark.style('default')
 @pytest.mark.backend('pgf')
 def test_rcupdate():
@@ -153,6 +153,10 @@ def test_rcupdate():
                                  '\\usepackage{sfmath}')}]
     tol = [6, 0]
     for i, rc_set in enumerate(rc_sets):
+        if i == 1:
+            for pkg in ['ucs', 'sfmath']:
+                if not _has_tex_package(pkg):
+                    pytest.skip(f'needs {pkg}.sty')
         with mpl.rc_context(rc_set):
             create_figure()
             compare_figure('pgf_rcupdate%d.pdf' % (i + 1), tol=tol[i])
