Add svg-flatten SVG feature tests

2 files changed, 76 insertions, 1 deletions

diff --git a/svg-flatten/src/nopencv_test.cpp b/svg-flatten/src/test/nopencv_test.cpp
index 17ba71e..2f358b2 100644
--- a/svg-flatten/src/nopencv_test.cpp
+++ b/svg-flatten/src/test/nopencv_test.cpp
@@ -15,7 +15,7 @@
 using namespace gerbolyze;
 using namespace gerbolyze::nopencv;
 
-char msg[1024];
+char msg[512];
 
 class TempfileHack {
 public:
diff --git a/svg-flatten/src/test/svg_tests.py b/svg-flatten/src/test/svg_tests.py
new file mode 100644
index 0000000..a5139ec
--- /dev/null
+++ b/svg-flatten/src/test/svg_tests.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+
+import tempfile
+import unittest
+from pathlib import Path
+import subprocess
+import os
+
+from PIL import Image
+import numpy as np
+
+def run_svg_flatten(input_file, output_file, **kwargs):
+    if 'SVG_FLATTEN' in os.environ:
+        svg_flatten = os.environ.get('SVG_FLATTEN')
+    elif (Path(__file__) / '../../build/svg-flatten').is_file():
+        svg_flatten = '../../build/svg-flatten'
+    elif Path('./build/svg-flatten').is_file():
+        svg_flatten = './build/svg-flatten'
+    else:
+        svg_flatten = 'svg-flatten'
+
+    args = [ svg_flatten,
+            *(arg for (key, value) in kwargs.items() for arg in (f'--{key.replace("_", "-")}', value)),
+            str(input_file), str(output_file) ]
+
+    try:
+        proc = subprocess.run(args, capture_output=True, check=True)
+    except:
+        print('Subprocess stdout:')
+        print(proc.stdout)
+        print('Subprocess stderr:')
+        print(proc.stderr)
+        raise
+
+class SVGRoundTripTests(unittest.TestCase):
+
+    def compare_images(self, reference, output, test_name, mean=0.01):
+        ref = np.array(Image.open(reference))
+        out = np.array(Image.open(output))
+        delta = np.abs(out - ref).astype(float) / 255
+
+        #print(f'{test_name}: mean={delta.mean():.5g}')
+
+        self.assertTrue(delta.mean() < mean,
+                f'Expected mean pixel difference between images to be <{mean}, was {delta.mean():.5g}')
+
+    def run_svg_round_trip_test(self, test_in_svg):
+        with tempfile.NamedTemporaryFile(suffix='.svg') as tmp_out_svg,\
+            tempfile.NamedTemporaryFile(suffix='.png') as tmp_out_png,\
+            tempfile.NamedTemporaryFile(suffix='.png') as tmp_in_png:
+
+            run_svg_flatten(test_in_svg, tmp_out_svg.name, format='svg')
+
+            subprocess.run(['resvg', tmp_out_svg.name, tmp_out_png.name], check=True, stdout=subprocess.DEVNULL)
+            subprocess.run(['resvg', test_in_svg, tmp_in_png.name], check=True, stdout=subprocess.DEVNULL)
+
+            try:
+                self.compare_images(tmp_in_png, tmp_out_png, test_in_svg.stem)
+            except AssertionError as e:
+                import shutil
+                shutil.copyfile(tmp_in_png.name, f'/tmp/gerbolyze-fail-{test_in_svg.stem}-in.png')
+                shutil.copyfile(tmp_out_png.name, f'/tmp/gerbolyze-fail-{test_in_svg.stem}-out.png')
+                foo = list(e.args)
+                foo[0] += '\nFailing test renderings copied to:\n'
+                foo[0] += f'  /tmp/gerbolyze-fail-{test_in_svg.stem}-{{in|out}}.png\n'
+                e.args = tuple(foo)
+                raise e
+
+for test_in_svg in Path('testdata/svg').glob('*.svg'):
+    # We need to make sure we capture the loop variable's current value here.
+    gen = lambda testcase: lambda self: self.run_svg_round_trip_test(testcase)
+    setattr(SVGRoundTripTests, f'test_{test_in_svg.stem}', gen(test_in_svg))
+
+if __name__ == '__main__':
+    unittest.main()