tests for ROUGE and readability

tests/test_metrics/test_readability.py

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+"""Tests for the readability metric."""
+
+import pytest
+
+from veritext.metrics import Readability, ReadabilityResult
+
+
+class TestReadability:
+    @pytest.fixture
+    def readability(self) -> Readability:
+        return Readability()
+
+    def test_name(self, readability: Readability) -> None:
+        assert readability.name == "readability"
+
+    def test_requires_reference(self, readability: Readability) -> None:
+        assert readability.requires_reference is False
+
+    def test_simple_text(self, readability: Readability) -> None:
+        # Simple children's text - short sentences, simple words
+        text = "The cat sat. The dog ran. I see a bird."
+        result = readability.score(text)
+
+        # Should have low grade level and high reading ease
+        assert result.flesch_kincaid_grade < 5.0
+        assert result.flesch_reading_ease > 80.0
+
+    def test_complex_text(self, readability: Readability) -> None:
+        # Complex academic text - long sentences, polysyllabic words
+        text = (
+            "The implementation of sophisticated computational methodologies "
+            "necessitates thorough understanding of algorithmic complexity "
+            "and architectural considerations."
+        )
+        result = readability.score(text)
+
+        # Should have high grade level and low reading ease
+        assert result.flesch_kincaid_grade > 12.0
+        assert result.flesch_reading_ease < 30.0
+
+    def test_medium_text(self, readability: Readability) -> None:
+        text = (
+            "The weather today is quite pleasant. "
+            "Many people are enjoying the sunshine in the park. "
+            "Children play while parents watch nearby."
+        )
+        result = readability.score(text)
+
+        # Should be middle of the road
+        assert 3.0 < result.flesch_kincaid_grade < 10.0
+        assert 50.0 < result.flesch_reading_ease < 90.0
+
+    def test_single_sentence(self, readability: Readability) -> None:
+        text = "The cat sat on the mat."
+        result = readability.score(text)
+
+        # Should compute without error
+        assert result.flesch_kincaid_grade is not None
+        assert result.flesch_reading_ease is not None
+
+    def test_single_word(self, readability: Readability) -> None:
+        text = "Cat"
+        result = readability.score(text)
+
+        # Should handle single word (1 word, 1 sentence, 1 syllable)
+        assert result.flesch_kincaid_grade is not None
+        assert result.flesch_reading_ease is not None
+
+    def test_empty_text(self, readability: Readability) -> None:
+        result = readability.score("")
+
+        assert result.flesch_kincaid_grade == 0.0
+        assert result.flesch_reading_ease == 0.0
+
+    def test_whitespace_only(self, readability: Readability) -> None:
+        result = readability.score("   \t\n  ")
+
+        assert result.flesch_kincaid_grade == 0.0
+        assert result.flesch_reading_ease == 0.0
+
+    def test_reference_ignored(self, readability: Readability) -> None:
+        text = "The cat sat on the mat."
+
+        # Score with no reference
+        result1 = readability.score(text)
+        # Score with reference (should be ignored)
+        result2 = readability.score(text, "Completely different text")
+        # Score with list of references
+        result3 = readability.score(text, ["ref1", "ref2"])
+
+        # All should produce identical results
+        assert result1.flesch_kincaid_grade == result2.flesch_kincaid_grade
+        assert result1.flesch_reading_ease == result2.flesch_reading_ease
+        assert result1.flesch_kincaid_grade == result3.flesch_kincaid_grade
+
+    def test_punctuation_handling(self, readability: Readability) -> None:
+        # Same words, different sentence structure
+        text1 = "The cat sat on the mat"  # 1 sentence
+        text2 = "The cat sat. On the mat."  # 2 sentences
+
+        result1 = readability.score(text1)
+        result2 = readability.score(text2)
+
+        # Different sentence counts should affect scores
+        assert result1.flesch_kincaid_grade != result2.flesch_kincaid_grade
+
+    def test_question_marks_count_sentences(self, readability: Readability) -> None:
+        text = "What is this? It is a test."
+        result = readability.score(text)
+
+        # Should count as 2 sentences
+        # With 7 words total, words_per_sentence = 3.5
+        assert result.flesch_kincaid_grade is not None
+
+    def test_exclamation_marks_count_sentences(self, readability: Readability) -> None:
+        text = "Wow! That is amazing!"
+        result = readability.score(text)
+
+        # Should count as 2 sentences
+        assert result.flesch_kincaid_grade is not None
+
+    def test_multiple_punctuation(self, readability: Readability) -> None:
+        text = "What?! That's crazy... Well then."
+        result = readability.score(text)
+
+        # Should handle gracefully
+        assert result.flesch_kincaid_grade is not None
+
+    def test_result_score_property(self, readability: Readability) -> None:
+        result = readability.score("The cat sat on the mat.")
+        assert result.score == result.flesch_reading_ease
+
+    def test_contractions(self, readability: Readability) -> None:
+        text = "I'm going to the store. It's not far away."
+        result = readability.score(text)
+
+        # Should handle contractions as words
+        assert result.flesch_kincaid_grade is not None
+        assert result.flesch_reading_ease is not None
+
+
+class TestReadabilityBatch:
+    @pytest.fixture
+    def readability(self) -> Readability:
+        return Readability()
+
+    def test_batch_score_basic(self, readability: Readability) -> None:
+        candidates = [
+            "The cat sat on the mat.",
+            "A dog ran through the park.",
+        ]
+        result = readability.batch_score(candidates)
+
+        assert result.count == 2
+        assert len(result.results) == 2
+
+    def test_batch_score_statistics(self, readability: Readability) -> None:
+        candidates = [
+            "Cat sat.",  # Very simple
+            "The implementation of sophisticated methodologies requires expertise.",
+        ]
+        result = readability.batch_score(candidates)
+
+        # Check statistics are computed
+        assert "flesch_kincaid_grade" in result.stats
+        assert "flesch_reading_ease" in result.stats
+
+        # First should be easier than second
+        assert (
+            result.results[0].flesch_reading_ease
+            > result.results[1].flesch_reading_ease
+        )
+
+    def test_batch_score_percentiles(self, readability: Readability) -> None:
+        candidates = ["a", "b", "c", "d", "e"]
+        result = readability.batch_score(candidates)
+
+        stats = result.stats["flesch_reading_ease"]
+        assert 25 in stats.percentiles
+        assert 50 in stats.percentiles
+        assert 75 in stats.percentiles
+        assert 95 in stats.percentiles
+
+    def test_batch_score_references_ignored(self, readability: Readability) -> None:
+        candidates = ["The cat sat.", "A dog ran."]
+
+        result1 = readability.batch_score(candidates)
+        result2 = readability.batch_score(candidates, ["ref1", "ref2"])
+
+        # Results should be identical
+        assert result1.results[0].flesch_kincaid_grade == (
+            result2.results[0].flesch_kincaid_grade
+        )
+
+    def test_batch_score_empty_list_raises(self, readability: Readability) -> None:
+        with pytest.raises(ValueError, match="empty"):
+            readability.batch_score([])
+
+
+class TestReadabilityResult:
+    def test_frozen(self) -> None:
+        from pydantic import ValidationError
+
+        result = ReadabilityResult(flesch_kincaid_grade=5.0, flesch_reading_ease=70.0)
+        with pytest.raises(ValidationError):
+            result.flesch_kincaid_grade = 6.0  # type: ignore[misc]
+
+    def test_values(self) -> None:
+        result = ReadabilityResult(flesch_kincaid_grade=8.5, flesch_reading_ease=65.0)
+        assert result.flesch_kincaid_grade == 8.5
+        assert result.flesch_reading_ease == 65.0
+
+    def test_score_property(self) -> None:
+        result = ReadabilityResult(flesch_kincaid_grade=8.5, flesch_reading_ease=65.0)
+        assert result.score == 65.0
+
+
+class TestSyllableCounting:
+    @pytest.fixture
+    def readability(self) -> Readability:
+        return Readability()
+
+    def test_monosyllabic_words(self, readability: Readability) -> None:
+        # All one-syllable words
+        text = "The cat sat on the mat."
+        result = readability.score(text)
+
+        # Should be very easy to read
+        assert result.flesch_reading_ease > 90.0
+
+    def test_polysyllabic_words(self, readability: Readability) -> None:
+        # Words with multiple syllables
+        text = "International communication facilitates understanding."
+        result = readability.score(text)
+
+        # Should be harder to read
+        assert result.flesch_reading_ease < 50.0