[AUR-421] base output post-processor that works using regex. (#20)

tests/test_post_processing.py

@@ -0,0 +1,38 @@
+import pytest
+
+from kotaemon.documents.base import Document
+from kotaemon.post_processing.extractor import RegexExtractor
+
+
+@pytest.fixture
+def regex_extractor():
+    return RegexExtractor(
+        pattern=r"\d+", output_map={"1": "One", "2": "Two", "3": "Three"}
+    )
+
+
+def test_run_document(regex_extractor):
+    document = Document(text="This is a test. 1 2 3")
+    extracted_document = regex_extractor(document)
+    extracted_texts = [each.text for each in extracted_document]
+    assert extracted_texts == ["One", "Two", "Three"]
+
+
+def test_is_document(regex_extractor):
+    assert regex_extractor.is_document(Document(text="Test"))
+    assert not regex_extractor.is_document("Test")
+
+
+def test_is_batch(regex_extractor):
+    assert regex_extractor.is_batch([Document(text="Test")])
+    assert not regex_extractor.is_batch(Document(text="Test"))
+
+
+def test_run_raw(regex_extractor):
+    output = regex_extractor("This is a test. 123")
+    assert output == ["123"]
+
+
+def test_run_batch_raw(regex_extractor):
+    output = regex_extractor(["This is a test. 123", "456"])
+    assert output == [["123"], ["456"]]