test: 补充知识处理、检索与 Agent 回归用例

覆盖切块、向量检索、工具调用和历史预算；模型相关用例使用桩。

backend/tests/core/test_file_validation.py

@@ -0,0 +1,100 @@
+"""
+Copyright 2024-2026 ReplyPier
+
+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
+"""
+
+import io
+import os
+
+import pytest
+from fastapi import HTTPException
+from starlette.datastructures import Headers, UploadFile
+
+from app.core.file_validation import PDF_MAGIC, read_validated, safe_filename
+
+PDF_TYPES = ("application/pdf",)
+
+
+def _pdf_upload(content: bytes, filename="doc.pdf", content_type="application/pdf"):
+    headers = Headers({"content-type": content_type}) if content_type else None
+    return UploadFile(io.BytesIO(content), filename=filename, headers=headers)
+
+
+# ---- safe_filename (path traversal) ----------------------------------------
+
+@pytest.mark.parametrize("name", ["../../etc/passwd", "..\\..\\x.pdf", "/abs/path/a.pdf", "a/b/c.pdf"])
+def test_safe_filename_cannot_escape_target_dir(name):
+    out = safe_filename(name)
+    assert "/" not in out and "\\" not in out
+    # The real property: joining under a base dir stays inside it.
+    joined = os.path.normpath(os.path.join("temp", out))
+    assert joined.startswith("temp" + os.sep)
+
+
+def test_safe_filename_prefixes_uuid_and_keeps_basename():
+    out = safe_filename("report.pdf")
+    assert out.endswith("_report.pdf")
+    assert out != safe_filename("report.pdf")  # unique per call
+
+
+def test_safe_filename_handles_empty_and_dots():
+    assert safe_filename("").endswith("_upload")
+    assert safe_filename("..").endswith("_upload")
+
+
+# ---- read_validated ---------------------------------------------------------
+
+@pytest.mark.asyncio
+async def test_read_validated_accepts_pdf():
+    content = b"%PDF-1.7\n...body..."
+    data = await read_validated(
+        _pdf_upload(content), max_size=1024, allowed_content_types=PDF_TYPES,
+        magic_prefix=PDF_MAGIC, label="PDF",
+    )
+    assert data == content
+
+
+@pytest.mark.asyncio
+async def test_read_validated_rejects_wrong_content_type():
+    with pytest.raises(HTTPException) as e:
+        await read_validated(
+            _pdf_upload(b"%PDF-1.7", content_type="text/html"),
+            max_size=1024, allowed_content_types=PDF_TYPES, magic_prefix=PDF_MAGIC, label="PDF",
+        )
+    assert e.value.status_code == 400
+
+
+@pytest.mark.asyncio
+async def test_read_validated_rejects_bad_magic_bytes():
+    with pytest.raises(HTTPException) as e:
+        await read_validated(
+            _pdf_upload(b"<html>not a pdf</html>"),
+            max_size=1024, allowed_content_types=PDF_TYPES, magic_prefix=PDF_MAGIC, label="PDF",
+        )
+    assert e.value.status_code == 400
+    assert "not a valid" in e.value.detail.lower()
+
+
+@pytest.mark.asyncio
+async def test_read_validated_rejects_oversize():
+    with pytest.raises(HTTPException) as e:
+        await read_validated(
+            _pdf_upload(b"%PDF-" + b"x" * 5000),
+            max_size=1024, allowed_content_types=PDF_TYPES, magic_prefix=PDF_MAGIC, label="PDF",
+        )
+    assert e.value.status_code == 413
+
+
+@pytest.mark.asyncio
+async def test_read_validated_rejects_empty():
+    with pytest.raises(HTTPException) as e:
+        await read_validated(
+            _pdf_upload(b""), max_size=1024, allowed_content_types=PDF_TYPES,
+            magic_prefix=PDF_MAGIC, label="PDF",
+        )
+    assert e.value.status_code == 400