1 files changed, 96 insertions, 0 deletions
diff --git a/tests/build/cythonize_newer_files.srctree b/tests/build/cythonize_newer_files.srctree
new file mode 100644
index 000000000..d2f65e2d6
--- /dev/null
+++ b/tests/build/cythonize_newer_files.srctree
@@ -0,0 +1,96 @@
+"""
+PYTHON test.py
+"""
+
+######## a.pyx ########
+
+######## test.py ########
+
+import os.path
+import time
+
+from Cython.Utils import GENERATED_BY_MARKER_BYTES, clear_function_caches, clear_method_caches
+from Cython.Build.Dependencies import cythonize, DependencyTree
+import Cython.Build.Dependencies
+
+getmtime = os.path.getmtime
+
+def wait_for_newer_mtime(filename, old_mtime):
+    mtime = old_mtime
+    while mtime <= old_mtime:
+        os.utime(filename, None)
+        mtime = getmtime(filename)
+    return mtime
+
+
+# test the mtime waiting itself
+with open("test_file.txt", 'wb') as f:
+    pass
+orig_mtime = getmtime("test_file.txt")
+wait_for_newer_mtime("test_file.txt", orig_mtime)
+assert orig_mtime < getmtime("test_file.txt")
+
+
+def fresh_cythonize(*args):
+    clear_function_caches()
+    clear_method_caches(DependencyTree.timestamp)
+    Cython.Build.Dependencies._dep_tree = None
+    cythonize(*args)
+
+
+assert not os.path.exists("a.c")
+
+# new
+fresh_cythonize("*.pyx")
+assert os.path.isfile("a.c")
+mtime = getmtime("a.c")
+
+# already exists
+fresh_cythonize("*.pyx")
+assert mtime == getmtime("a.c")
+
+# outdated
+wait_for_newer_mtime("a.pyx", mtime)
+assert mtime < getmtime("a.pyx")
+fresh_cythonize("*.pyx")
+new_mtime = getmtime("a.c")
+assert mtime < new_mtime
+
+# now up to date
+fresh_cythonize("*.pyx")
+assert new_mtime == getmtime("a.c")
+
+# different Cython version (even though newer)
+marker = b"/* Generated by Cython "
+assert GENERATED_BY_MARKER_BYTES.startswith(marker)  # safety belt
+with open("a.c", "rb") as f:
+    content = f.read()
+
+assert content.startswith(GENERATED_BY_MARKER_BYTES)
+content = marker + b"123" + content[len(marker):]
+
+with open("a.c", "wb") as f:
+    f.write(content)
+wait_for_newer_mtime("a.c", new_mtime)
+
+other_cython_mtime = getmtime("a.c")
+assert mtime < new_mtime < other_cython_mtime
+
+fresh_cythonize("*.pyx")
+latest_mtime = getmtime("a.c")
+assert mtime < new_mtime < other_cython_mtime <= latest_mtime
+
+with open("a.c", "rb") as f:
+    assert f.read(len(GENERATED_BY_MARKER_BYTES)) == GENERATED_BY_MARKER_BYTES  # file was rewritten
+
+# now up to date
+fresh_cythonize("*.pyx")
+assert mtime < new_mtime < other_cython_mtime <= latest_mtime == getmtime("a.c")
+
+# force regeneration with environment variable
+os.environ["CYTHON_FORCE_REGEN"] = "1"
+time.sleep(0.1)
+
+assert latest_mtime == getmtime("a.c")
+fresh_cythonize("*.pyx")
+assert latest_mtime < getmtime("a.c")