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ragflow/test/unit_test/rag/test_naive_merge.py
Jack 4b4a6e72f0 fix(chunker): unify TokenChunker merge and strip coord tags in Python JSON path (#18002)
Unifies the Go TokenChunker merge path on a single `mergeUnits` core and
fixes coordinate-tag drift in the Python JSON merge at `overlap > 0`.
Rebased on top of #17979 (delimiter_mode convergence).
2026-08-07 21:55:07 +08:00

385 lines
16 KiB
Python

#
# Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Regression tests for ``naive_merge`` / ``naive_merge_with_images``.
Guards against:
* the regression introduced by commit db0f6840d (#11434) where the default
(non-custom-delimiter) path stopped splitting oversized sections at sentence
boundaries, and the overlap prefix was not counted toward a chunk's token
budget;
* the soft-cap bug where chunks systematically overshot ``chunk_token_num`` by
up to one unit (sentence / line) because the size check fired *after* the
append instead of using a projected-total check.
"""
import itertools
import re
import pytest
from rag import nlp
from rag.nlp import naive_merge, naive_merge_with_images, MergeStrategy
DEFAULT_DELIMITER = "\n!?。;!?"
@pytest.fixture(autouse=True)
def word_count_tokens(monkeypatch):
"""Count tokens as whitespace-delimited words (ignoring ``@@..`` position tags).
Deterministic and tokenizer-independent so chunk-size assertions are exact.
"""
def fake_num_tokens(s):
s = re.sub(r"@@[0-9]+\t[^\t\n]*", "", s or "")
return len(s.split())
monkeypatch.setattr(nlp, "num_tokens_from_string", fake_num_tokens)
return fake_num_tokens
def _tok(s):
return len(re.sub(r"@@[0-9]+\t[^\t\n]*", "", s or "").split())
def _nonempty(chunks):
return [c for c in chunks if c.strip()]
# --------------------------------------------------------------------------- #
# naive_merge — text path
# --------------------------------------------------------------------------- #
@pytest.mark.p2
def test_oversized_section_is_split_at_sentence_boundaries():
# One section far larger than chunk_token_num, sentences separated by '\n'.
sentence = " ".join(["word"] * 10) # 10 tokens
section = "\n".join([sentence] * 20) # 200 tokens, single section
assert _tok(section) == 200
chunks = _nonempty(naive_merge([section], chunk_token_num=50, delimiter=DEFAULT_DELIMITER))
# Pre-regression behaviour: the section is broken into several chunks
# instead of a single oversized one.
assert len(chunks) > 1
# OVER_CAP (default) allows at most one boundary paragraph to overflow the
# soft cap: a chunk may exceed ``chunk_token_num`` by one paragraph (10
# tokens here) but never more. The old pairwise code packed to strictly
# ``<= cap``; greedy OVER_CAP instead closes the chunk right after the
# overflowing paragraph.
assert all(_tok(c) <= 50 + 10 for c in chunks)
# Content is preserved.
assert "".join(chunks).count("word") == 200
@pytest.mark.p2
def test_small_section_is_split_at_delimiter_boundary():
# A small section (well under chunk_token_num) that contains a delimiter
# must still be broken at the delimiter: the delimiter is a chunk boundary
# and its text must never leak into a chunk. The old code kept the whole
# section when it fit, so the delimiter text survived inside one chunk.
small_section = "first part。second part。third part" # 6 words, 2 delimiters
chunks = _nonempty(naive_merge([small_section], chunk_token_num=128, delimiter=DEFAULT_DELIMITER))
# Delimiter text never appears inside any chunk.
assert all("" not in c for c in chunks)
# Every delimiter-separated piece is present (content preserved).
joined = "".join(chunks)
assert "first part" in joined and "second part" in joined and "third part" in joined
@pytest.mark.p2
def test_small_section_with_images_split_at_delimiter_boundary():
# Same guarantee for the image path: a small text carrying an image is
# still split at the delimiter so the delimiter text does not leak.
small_section = "alpha。beta。gamma" # 3 words, 2 delimiters
texts = [(small_section, "")]
images = [object()]
chunks, imgs = naive_merge_with_images(texts, images, chunk_token_num=128, delimiter=DEFAULT_DELIMITER)
nonempty = _nonempty(chunks)
assert all("" not in c for c in nonempty)
# The single image travels with its (split) text.
assert len(chunks) == len(imgs)
@pytest.mark.p2
def test_small_sections_accumulate_under_over_cap():
# Default strategy is OVER_CAP: adjacent small paragraphs are greedily
# accumulated while the projected total stays under chunk_token_num, not
# capped at fixed-size pairs. No atom-split is performed; the delimiter
# boundary (paragraph) is the unit.
sentences = ["alpha beta gamma delta" for _ in range(8)] # 4 tokens each
chunks = _nonempty(naive_merge(sentences, chunk_token_num=50, delimiter=DEFAULT_DELIMITER))
assert len(chunks) == 1
assert _tok(chunks[0]) == 32
# Content is preserved (32 tokens total).
assert sum(_tok(c) for c in chunks) == 32
@pytest.mark.p2
def test_default_delimiters_are_honored_without_backticks():
# Sentences delimited by '?' and '!' (part of the default set) must split.
section = ("q " * 10).strip() + "?" + ("r " * 10).strip() + "!" + ("s " * 10).strip()
chunks = _nonempty(naive_merge([section], chunk_token_num=12, delimiter=DEFAULT_DELIMITER))
assert len(chunks) >= 2
@pytest.mark.p2
def test_empty_delimiter_falls_back_to_token_size_merge():
# token_chunker.py calls naive_merge with delimiter="" as a size-only fallback.
sections = [f"sentence number {i} here" for i in range(30)] # 4 tokens each
chunks = _nonempty(naive_merge(sections, chunk_token_num=20, delimiter=""))
assert len(chunks) >= 1
# Must not crash and must not explode into per-character chunks.
assert len(chunks) < len(sections)
@pytest.mark.p2
def test_overlap_prefix_is_never_dropped_at_overflow():
# With overlap, each chunk = overlap-prefix + new content. The unified
# strategy applies the overlap UNCONDITIONALLY at every boundary: it is
# never dropped for not fitting the budget, so context stays continuous
# across boundaries even when the chunk overshoots chunk_token_num by the
# overlap amount.
sentences = [" ".join(["w"] * 10) for _ in range(30)]
# UNDER_CAP (strict): content chunks never overflow chunk_token_num, so the
# overlap-prefix budget check is the only thing under test here.
chunks = _nonempty(naive_merge(sentences, chunk_token_num=50, delimiter=DEFAULT_DELIMITER, overlapped_percent=20, strategy=MergeStrategy.UNDER_CAP))
assert len(chunks) > 1
# The overlap prefix is always present at every boundary: each chunk (after
# the first) starts with the tail of the previous chunk.
for prev, cur in itertools.pairwise(chunks):
cut = int(len(prev) * (100 - 20) / 100.0)
assert prev[cut:] and cur.startswith(prev[cut:]), "overlap prefix missing at boundary"
# And because the prefix is never dropped, some chunks exceed the budget.
assert any(_tok(c) > 50 for c in chunks)
# --------------------------------------------------------------------------- #
# Custom-delimiter path (intended #11434 behaviour must be preserved)
# --------------------------------------------------------------------------- #
@pytest.mark.p2
def test_custom_delimiter_ignores_chunk_size():
text = "partA##partB##partC"
# Backtick-wrapped custom delimiter -> every segment is its own chunk,
# regardless of chunk_token_num.
chunks = [c.strip() for c in naive_merge([text], chunk_token_num=1000, delimiter="\n。`##`")]
assert chunks == ["partA", "partB", "partC"]
@pytest.mark.p2
def test_custom_delimiter_does_not_size_merge():
parts = [f"seg{i}" for i in range(5)]
text = "##".join(parts)
chunks = [c.strip() for c in naive_merge([text], chunk_token_num=1000, delimiter="`##`")]
assert chunks == parts
# --------------------------------------------------------------------------- #
# naive_merge_with_images — image path
# --------------------------------------------------------------------------- #
@pytest.mark.p2
def test_images_oversized_section_is_split():
sentence = " ".join(["word"] * 10)
section = "\n".join([sentence] * 20) # 200 tokens
texts = [(section, "")]
images = [None]
chunks, imgs = naive_merge_with_images(texts, images, chunk_token_num=50, delimiter=DEFAULT_DELIMITER)
nonempty = _nonempty(chunks)
assert len(nonempty) > 1
# Returned lists stay aligned.
assert len(chunks) == len(imgs)
# OVER_CAP allows one boundary paragraph (10 tokens) to overflow the cap.
assert all(_tok(c) <= 50 + 10 for c in nonempty)
@pytest.mark.p2
def test_images_custom_delimiter_preserved():
chunks, imgs = naive_merge_with_images([("x##y##z", "")], [None], chunk_token_num=1000, delimiter="`##`")
assert [c.strip() for c in chunks] == ["x", "y", "z"]
assert len(chunks) == len(imgs)
@pytest.mark.p2
def test_images_plain_string_input():
# texts may be plain strings (not tuples).
sentence = " ".join(["word"] * 10)
section = "\n".join([sentence] * 20)
chunks, imgs = naive_merge_with_images([section], [None], chunk_token_num=50, delimiter=DEFAULT_DELIMITER)
assert len(_nonempty(chunks)) > 1
assert len(chunks) == len(imgs)
@pytest.mark.p2
def test_images_mismatched_lengths_returns_empty():
assert naive_merge_with_images(["a"], [], chunk_token_num=50) == ([], [])
@pytest.mark.p2
def test_images_shared_lazyimage_not_stacked_across_split_sentences():
# A single section carries one LazyImage. After splitting into sentences that
# merge back into one chunk, the shared image must NOT be duplicated/stacked
# (concat_img would otherwise concatenate the blob list with itself).
from rag.utils.lazy_image import LazyImage
image = LazyImage([b"FAKEBLOB"])
section = "\n".join([" ".join(["word"] * 10)] * 20)
_, imgs = naive_merge_with_images([(section, "")], [image], chunk_token_num=50, delimiter=DEFAULT_DELIMITER)
for im in imgs:
if isinstance(im, LazyImage):
assert len(im._blobs) == 1 # never grows beyond the single source blob
@pytest.mark.p2
def test_images_distinct_lazyimages_are_concatenated():
# Two different sections (small enough to land in one chunk) with distinct
# images must still be merged together.
from rag.utils.lazy_image import LazyImage
a = LazyImage([b"BLOB_A"])
b = LazyImage([b"BLOB_B"])
texts = [("alpha beta gamma", ""), ("delta epsilon zeta", "")]
_, imgs = naive_merge_with_images(texts, [a, b], chunk_token_num=100, delimiter=DEFAULT_DELIMITER)
nonempty_imgs = [im for im in imgs if im is not None]
assert len(nonempty_imgs) == 1
merged = nonempty_imgs[0]
assert isinstance(merged, LazyImage)
assert merged._blobs == [b"BLOB_A", b"BLOB_B"]
# --------------------------------------------------------------------------- #
# Hard cap on chunk size (overshoot bug fix)
# --------------------------------------------------------------------------- #
@pytest.mark.p2
def test_strict_cap_no_overlap_packs_to_budget():
# "strict cap" == UNDER_CAP: chunks never overflow chunk_token_num.
sections = [" ".join(["w"] * 25) for _ in range(8)]
chunks = _nonempty(naive_merge(sections, chunk_token_num=50, delimiter=DEFAULT_DELIMITER, strategy=MergeStrategy.UNDER_CAP))
assert len(chunks) >= 3
assert all(_tok(c) <= 50 for c in chunks)
@pytest.mark.p2
def test_strict_cap_overlap_never_dropped_at_overflow_boundary():
# UNDER_CAP chunks are exactly 20 tokens (two 10-token sentences). A 20%
# overlap prefix is 4 tokens; 20 + 4 > 20, so under the old fit-check the
# prefix was dropped. The unified strategy applies it UNCONDITIONALLY, so
# the chunk overshoots the strict cap by the overlap amount rather than
# losing boundary context.
sentences = [" ".join(["w"] * 10) for _ in range(20)]
chunks = _nonempty(naive_merge(sentences, chunk_token_num=20, delimiter=DEFAULT_DELIMITER, overlapped_percent=20, strategy=MergeStrategy.UNDER_CAP))
assert len(chunks) > 1
for prev, cur in itertools.pairwise(chunks):
cut = int(len(prev) * (100 - 20) / 100.0)
assert prev[cut:] and cur.startswith(prev[cut:]), "overlap prefix missing at boundary"
assert any(_tok(c) > 20 for c in chunks)
@pytest.mark.p2
def test_no_atom_split_keeps_oversize_unit_whole(monkeypatch):
# The strict-cap atom sub-splitter is gone. A single unbroken unit that
# exceeds chunk_token_num is kept whole (the model layer truncates); this
# is the fix for the token_size=1 -> 1-token-per-chunk regression.
def char_count_tokens(s):
return len(s or "")
monkeypatch.setattr(nlp, "num_tokens_from_string", char_count_tokens)
big_section = "a" * 80 # unbroken, token-dense string
chunks = _nonempty(naive_merge([big_section], chunk_token_num=50, delimiter=DEFAULT_DELIMITER))
assert len(chunks) == 1
assert "".join(chunks).strip() == big_section
@pytest.mark.p2
def test_strict_cap_overlap_chosen_when_it_fits():
# UNDER_CAP packs two 7-token sentences into a 14-token chunk, leaving
# headroom. A 20% overlap prefix is 4 tokens; 14 + 4 <= 20, so the prefix is
# kept (the overlap is chosen because it fits the strict cap).
sentences = [" ".join(["w"] * 7) for _ in range(20)]
chunks = _nonempty(naive_merge(sentences, chunk_token_num=20, delimiter=DEFAULT_DELIMITER, overlapped_percent=20, strategy=MergeStrategy.UNDER_CAP))
assert all(_tok(c) <= 20 for c in chunks)
overlap_seen = False
for a, b in itertools.pairwise(chunks):
a_tokens = a.split()
b_tokens = b.split()
if a_tokens and b_tokens and any(t in b_tokens for t in a_tokens):
overlap_seen = True
break
assert overlap_seen
@pytest.mark.p2
def test_images_strict_cap_packs_to_budget():
sections = [" ".join(["w"] * 25) for _ in range(6)]
images = [None] * len(sections)
chunks, imgs = naive_merge_with_images(sections, images, chunk_token_num=50, delimiter=DEFAULT_DELIMITER, strategy=MergeStrategy.UNDER_CAP)
nonempty = _nonempty(chunks)
assert all(_tok(c) <= 50 for c in nonempty)
assert len(chunks) == len(imgs)
@pytest.mark.p2
def test_strict_cap_pos_text_does_not_overshoot_budget(monkeypatch):
"""Verify that pos text addition does not push chunk over chunk_token_num."""
def char_count_tokens(s):
return len(s or "")
monkeypatch.setattr(nlp, "num_tokens_from_string", char_count_tokens)
# section is ~15 chars, pos is 10 chars. chunk_token_num is 20.
# NOTE: ``pos`` is attached post-merge (in ``_reconstruct_text_chunk``), so it
# is NOT counted in the merge-paragraphs token budget. Greedy UNDER_CAP packs
# the text up to the cap; the reconstructed chunk then gains the pos tag on
# top. The honest bound is therefore ``cap + len(pos)`` — the pos tag is not
# budgeted away. (Accounting pos in the merge budget would be a separate fix.)
pos_tag = "@@12345678"
sections = [("\na" * 15, pos_tag)]
chunks = _nonempty(naive_merge(sections, chunk_token_num=20, delimiter=DEFAULT_DELIMITER, strategy=MergeStrategy.UNDER_CAP))
assert all(char_count_tokens(c) <= 20 + len(pos_tag) for c in chunks)
@pytest.mark.p2
def test_empty_delimiter_keeps_unit_whole():
# Empty delimiter -> no split; the whole section is one chunk (no atom-split).
# The model layer truncates oversize units.
long_section = "word " * 100 # ~100 tokens
chunks = _nonempty(naive_merge([long_section], chunk_token_num=30, delimiter=""))
assert len(chunks) == 1
assert "".join(chunks).count("word") == 100
@pytest.mark.p2
def test_images_empty_delimiter_keeps_unit_whole():
long_section = "word " * 100
images = [None]
chunks, imgs = naive_merge_with_images([long_section], images, chunk_token_num=30, delimiter="")
nonempty = _nonempty(chunks)
assert len(nonempty) == 1
assert "".join(nonempty).count("word") == 100
assert len(chunks) == len(imgs)