Feat: Intercept 'tempfile' argument of the PdfComparator to improve it (#69)

Author: adrien-berchet

dir_content_diff/base_comparators.py

@@ -15,6 +15,7 @@
 import re
 from abc import ABC
 from abc import abstractmethod
+from pathlib import Path
 from xml.etree import ElementTree
 
 import dictdiffer
@@ -625,4 +626,27 @@ def diff(self, ref, comp, *args, **kwargs):
             num_threads (int): If set to 2 (the default), the image conversion are processed in
                 parallel. If set to 1 it is processed sequentially.
         """
+        tempdir = kwargs.pop("tempdir", None)
+        if tempdir is not None:
+            relative_parts = []
+            for i, j in zip(ref.parts[::-1], comp.parts[::-1]):  # pragma: no branch
+                if i != j:
+                    break
+                relative_parts.append(i)
+            if not relative_parts:
+                relative_parts.append(comp.name)
+            relative_parts[-1] = "diff-pdf-" + relative_parts[-1]
+            new_tempdir = Path(tempdir) / Path(*relative_parts[::-1])
+
+            # Deduplicate name if needed
+            num = 1
+            while True:
+                try:
+                    new_tempdir.mkdir(parents=True, exist_ok=False)
+                    break
+                except FileExistsError:
+                    new_tempdir = new_tempdir.with_name(new_tempdir.name + f"_{num}")
+                    num += 1
+
+            kwargs["tempdir"] = new_tempdir
         return not pdf_similar(ref, comp, *args, **kwargs)

tests/test_base.py

@@ -17,6 +17,7 @@
 import copy
 import json
 import re
+import shutil
 
 import dictdiffer
 import pytest
@@ -646,6 +647,59 @@ def test_initodict(self, ref_tree):
                 "section2": {"attr3": [1, 2, "a", "b"], "attr4": {"a": 1, "b": [1, 2]}},
             }
 
+    class TestPdfComparator:
+        """Test the PDF comparator."""
+
+        def test_diff_tempfile(self, ref_tree, res_tree_equal):
+            """Test the custom tempfile option."""
+            ref_file = ref_tree / "file.pdf"
+            res_file = res_tree_equal / "file.pdf"
+
+            # Copy the initial data into a nested directory
+            nested_ref = res_tree_equal / "nested" / "ref"
+            nested_res = res_tree_equal / "nested" / "res"
+            shutil.copytree(res_tree_equal, nested_res)
+            shutil.copytree(ref_tree, nested_ref)
+
+            # Compute difference on initial data
+            diff = dir_content_diff.compare_files(
+                ref_file,
+                res_file,
+                dir_content_diff.PdfComparator(),
+                tempdir=res_tree_equal,
+            )
+            assert not diff
+            assert (res_tree_equal / "diff-pdf-file.pdf" / "diff-1.png").exists()
+
+            # Compute difference on nested data
+            ref_file = nested_ref / "file.pdf"
+            res_file = nested_res / "file.pdf"
+            diff_nested = dir_content_diff.compare_files(
+                ref_file,
+                res_file,
+                dir_content_diff.PdfComparator(),
+                tempdir=nested_res.parent,
+            )
+            assert not diff_nested
+            assert (nested_res.parent / "diff-pdf-file.pdf" / "diff-1.png").exists()
+
+            # Compare files with different names and with existing tempdir
+            other_res_file = res_file.with_name("other_file.pdf")
+            shutil.copyfile(res_file, other_res_file)
+            (res_tree_equal / "diff-pdf-other_file.pdf").mkdir()
+            other_diff = dir_content_diff.compare_files(
+                ref_file,
+                other_res_file,
+                dir_content_diff.PdfComparator(),
+                tempdir=res_tree_equal,
+            )
+            assert not other_diff
+            assert (res_tree_equal / "diff-pdf-other_file.pdf").exists()
+            assert not list((res_tree_equal / "diff-pdf-other_file.pdf").iterdir())
+            assert (
+                res_tree_equal / "diff-pdf-other_file.pdf_1" / "diff-1.png"
+            ).exists()
+
 
 class TestRegistry:
     """Test the internal registry."""