Merge pull request #634 from JulienBortolussiAda/raise_empty_diff_error

e3.diff.patch raise EmptyDiffError when doing nothing

src/e3/diff.py

@@ -16,6 +16,17 @@
 
 
 class DiffError(e3.error.E3Error):
+    """Error returned when the patch command fails."""
+
+    pass
+
+
+class EmptyDiffError(DiffError):
+    """Error returned when the patch is empty.
+
+    These situation can occur when all the patched files are discarded.
+    """
+
     pass
 
 
@@ -268,6 +279,6 @@ def process_git_patch() -> int:
         files_to_patch = process_regular_patch()
 
     if files_to_patch == 0:
-        raise DiffError(origin="patch", message="No file to patch")
+        raise EmptyDiffError(origin="patch", message="No file to patch")
 
     apply_patch(filtered_patch)

tests/tests_e3/diff/main_test.py

@@ -58,7 +58,7 @@ def test_patch_ignore_all(caplog):
 
     e3.fs.cp(file_to_patch, current_dir)
     e3.fs.cp(file_patch2, current_dir)
-    with pytest.raises(e3.diff.DiffError):
+    with pytest.raises(e3.diff.EmptyDiffError):
         e3.diff.patch("patch2.txt", current_dir, discarded_files=lambda x: True)
 
 
@@ -144,7 +144,7 @@ def test_patch_git_format_ignore():
     assert "That's nice it's working !" in content
 
     e3.fs.cp(file_to_patch, cwd)
-    with pytest.raises(e3.diff.DiffError):
+    with pytest.raises(e3.diff.EmptyDiffError):
         e3.diff.patch("git_diff.patch", cwd, discarded_files=["git_file.txt"])
 
     with open(os.path.join(cwd, "git_file.txt")) as fd:
@@ -190,7 +190,7 @@ def test_patch_git_with_headers():
 
     e3.fs.rm("file1")
     e3.fs.rm("file2")
-    with pytest.raises(e3.diff.DiffError):
+    with pytest.raises(e3.diff.EmptyDiffError):
         e3.diff.patch("git_patch_with_header", cwd, discarded_files=["file*"])
 
     assert not os.path.isfile("file1")