tests: Add umockdev based testing

Initially only the vfs5011 driver is tested. Please note that these
tests will be unreliable before umockdev 0.13.2.

See also https://github.com/martinpitt/umockdev/pull/92

tests/umockdev-test.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import os.path
+import shutil
+import tempfile
+import subprocess
+
+if len(sys.argv) != 2:
+    print("You need to specify exactly one argument, the directory with test data")
+
+edir = os.path.dirname(sys.argv[0])
+ddir = sys.argv[1]
+
+tmpdir = tempfile.mkdtemp(prefix='libfprint-umockdev-test-')
+
+assert os.path.isdir(ddir)
+assert os.path.isfile(os.path.join(ddir, "device"))
+
+def cmp_pngs(png_a, png_b):
+    print("Comparing PNGs %s and %s" % (png_a, png_b))
+    import cairo
+    img_a = cairo.ImageSurface.create_from_png(png_a)
+    img_b = cairo.ImageSurface.create_from_png(png_b)
+
+    assert img_a.get_format() == cairo.FORMAT_RGB24
+    assert img_b.get_format() == cairo.FORMAT_RGB24
+    assert img_a.get_width() == img_b.get_width()
+    assert img_a.get_height() == img_b.get_height()
+    assert img_a.get_stride () == img_b.get_stride()
+
+    data_a = img_a.get_data()
+    data_b = img_b.get_data()
+    stride = img_a.get_stride()
+
+    for x in range(img_a.get_width()):
+        for y in range(img_a.get_height()):
+            assert(data_a[y * stride + x * 4] == data_b[y * stride + x * 4])
+
+def capture():
+    ioctl = os.path.join(ddir, "capture.ioctl")
+    device = os.path.join(ddir, "device")
+    dev = open(ioctl).readline().strip()
+    assert dev.startswith('@DEV ')
+    dev = dev[5:]
+
+    subprocess.check_call(['umockdev-run', '-d', device,
+                                           '-i', "%s=%s" % (dev, ioctl),
+                                           '--',
+                                           '%s' % os.path.join(edir, "capture.py"),
+                                             '%s' % os.path.join(tmpdir, "capture.png")])
+
+    assert os.path.isfile(os.path.join(tmpdir, "capture.png"))
+    if os.path.isfile(os.path.join(ddir, "capture.png")):
+        # Compare the images, they need to be identical
+        cmp_pngs(os.path.join(tmpdir, "capture.png"), os.path.join(ddir, "capture.png"))
+
+try:
+    if os.path.exists(os.path.join(ddir, "capture.ioctl")):
+        capture()
+
+finally:
+    shutil.rmtree(tmpdir)
+