Nan Cheng

22 papers B 1C 4Misc 1Journal 14Unranked 2
YearRankTypeTitle / Venue / Authors
2026 J jnl
CoRR
Yu Sun, Yaqiong Liu, Nan Cheng, Jiayuan Li, Zihan Jia, Xialin Du, Mugen Peng
2026 J jnl
IEEE Computer Graphics and Applications
Shuo Wang, Tong Ren, Nan Cheng, Rong Wang, Li Zhang
2026 J jnl
Neurocomputing
Kangkang Lu, Yanhua Yu, Ruopei Guo, Nan Cheng, Zhiyong Huang, Yunshan Ma, MeiYu Liang, Yuling Wang, Xiting Qin, Yimeng Ren, Tat-Seng Chua
2026 J jnl
IEEE Trans. Netw. Serv. Manag.
Yuanzhen Jiang, Yaqiong Liu, Xidian Wang, Nan Cheng, Zihan Jia, Duo Shi, Zhe Lv, Zhouyuan Li, Yan Zhang
2025 J jnl
CoRR
Jialin Wan, Nan Cheng, Jinglong Shen
2025 B conf
SMC
Zicheng Tang, Nan Cheng, Yaying Zhang
2025 J jnl
CoRR
Shuo Wang, Tong Ren, Nan Cheng, Li Zhang, Rong Wang
2025 J jnl
CoRR
Shuo Wang, Tong Ren, Nan Cheng, Rong Wang, Li Zhang
2025 J jnl
CoRR
Feng Chen, Allan Raventós, Nan Cheng, Surya Ganguli, Shaul Druckmann
2025 J jnl
CoRR
Shuo Wang, Tong Ren, Nan Cheng, Rong Wang, Li Zhang
2024 J jnl
CoRR
Jun-Jie Zhang, Jiahao Song, Xiu-Cheng Wang, Fu-Peng Li, Zehan Liu, Jian-Nan Chen, Haoning Dang, Shiyao Wang, Yiyan Zhang, Jianhui Xu, Chunxiang Shi, Fei Wang, Long-Gang Pang, Nan Cheng, Weiwei Zhang, Duo Zhang, Deyu Meng
2018 J jnl
Biomed. Signal Process. Control.
Yi Xia, Jun Zhang, Qiang Ye, Nan Cheng, Yixiang Lu, Dexiang Zhang
2018 J jnl
Web Intell.
Xi Wu, Chen Tang, Xu Chen, Shengqiang Xu, Nan Cheng, Ning An
2017 conf
BIBM
Xi Wu, Xu Chen, You Duan, Shengqiang Xu, Nan Cheng, Ning An
2017 J jnl
Biomed. Signal Process. Control.
Yi Xia, Qingwei Gao, Nan Cheng, Yixiang Lu, Dexiang Zhang, Qiang Ye
2016 conf
CISP-BMEI
Yao Liu, Nan Cheng, Shengqiang Xu, Yining Sun, Xianjun Yang
2014 C conf
CIS
Wei Wu, Nan Cheng, Yubin Wang
2014 C conf
CIS
Nan Cheng, Wei Wu, Yubin Wang
2014 C conf
CIS
Yubin Wang, Chao Li, Nan Cheng
2012 C conf
ICCC
Peng Gao, Dexiang Meng, Shoufeng Wang, Dongchen Zhang, Nan Cheng, Yi Zhan
2011 J jnl
J. Zhejiang Univ. Sci. C
Zhenhua Li, Bang-hong Guo, Zheng-jun Wei, Songhao Liu, Nan Cheng, Jin-dong Wang, Jianjun Guo, Long Yan
2010 Misc conf
ICNC
Huapu Lu, Xinxin Yu, Jianan Zhu, Xiaoqiang Zhao, Nan Cheng
tests/integration/test_base_extractor.py
← Index tests/integration/test_base_extractor.py python
"""
Integration tests for the base Extractor class.
"""
import pytest
import hashlib
import math
from unittest.mock import Mock, patch, MagicMock
from collections import Counter

pytestmark = [pytest.mark.integration]


class TestExtractorStaticMethods:
    """Tests for static methods in Extractor class."""

    def test_process_binary_string_printable(self):
        """Test processing a printable binary string."""
        from redb.extractors.extractor import Extractor

        # Test with printable ASCII characters
        input_bytes = b"Hello World\x00\x00\x00"
        result = Extractor.process_binary_string(input_bytes)
        assert result == "Hello World"

    def test_process_binary_string_non_printable(self):
        """Test processing a string with non-printable characters."""
        from redb.extractors.extractor import Extractor

        # Test with non-printable characters
        input_bytes = b"\x01\x02Hello\x00"
        result = Extractor.process_binary_string(input_bytes)
        assert "\\x01" in result
        assert "\\x02" in result
        assert "Hello" in result

    def test_process_binary_string_empty(self):
        """Test processing an empty binary string."""
        from redb.extractors.extractor import Extractor

        input_bytes = b"\x00\x00\x00"
        result = Extractor.process_binary_string(input_bytes)
        assert result == ""

    def test_process_binary_string_all_printable(self):
        """Test processing a fully printable string."""
        from redb.extractors.extractor import Extractor

        input_bytes = b"TestString123"
        result = Extractor.process_binary_string(input_bytes)
        assert result == "TestString123"

    def test_remove_non_utf8_valid(self):
        """Test removing non-UTF8 characters from valid UTF8 string."""
        from redb.extractors.extractor import Extractor

        input_bytes = b"Hello World"
        result = Extractor.remove_non_utf8(input_bytes)
        assert result == b"Hello World"

    def test_remove_non_utf8_with_invalid(self):
        """Test removing non-UTF8 characters from mixed string."""
        from redb.extractors.extractor import Extractor

        # Mix of valid UTF8 and invalid bytes
        input_bytes = b"Hello\xff\xfeWorld"
        result = Extractor.remove_non_utf8(input_bytes)
        # Should remove the invalid bytes
        assert b"\xff" not in result
        assert b"\xfe" not in result
        assert b"Hello" in result
        assert b"World" in result

    def test_remove_non_utf8_empty(self):
        """Test removing non-UTF8 from empty string."""
        from redb.extractors.extractor import Extractor

        result = Extractor.remove_non_utf8(b"")
        assert result == b""


class TestExtractorEntropyCalculation:
    """Tests for entropy calculation in Extractor class."""

    def test_calculate_entropy_empty_data(self, elf_binary_path, mock_logger):
        """Test entropy calculation with empty data."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            result = extractor.calculate_entropy(b"")
            assert result == 0.0

    def test_calculate_entropy_uniform_data(self, elf_binary_path, mock_logger):
        """Test entropy calculation with uniform (low entropy) data."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            # All same bytes = 0 entropy
            uniform_data = b"\x00" * 256
            result = extractor.calculate_entropy(uniform_data)
            assert result == 0.0

    def test_calculate_entropy_random_data(self, elf_binary_path, mock_logger, high_entropy_data):
        """Test entropy calculation with random (high entropy) data."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            result = extractor.calculate_entropy(high_entropy_data)
            # Random data should have entropy close to 8 (max for bytes)
            assert result > 7.0

    def test_calculate_entropy_binary_data(self, elf_binary_path, mock_logger):
        """Test entropy calculation with binary data."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            # Two equally distributed values = 1 bit entropy
            binary_data = b"\x00\x01" * 128
            result = extractor.calculate_entropy(binary_data)
            assert abs(result - 1.0) < 0.01

    def test_calculate_entropy_string_data(self, elf_binary_path, mock_logger):
        """Test entropy calculation with string data."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            # String with two equally distributed characters
            string_data = "ab" * 100
            result = extractor.calculate_entropy(string_data)
            assert abs(result - 1.0) < 0.01


class TestExtractorInitialization:
    """Tests for Extractor initialization."""

    def test_extractor_hashes_computed_on_init(self, elf_binary_path, mock_logger, known_hashes):
        """Test that hashes are computed during initialization."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)

            assert extractor.md5 == known_hashes['md5']
            assert extractor.sha1 == known_hashes['sha1']
            assert extractor.sha256 == known_hashes['sha256']

    def test_extractor_hash_dataclass_created(self, elf_binary_path, mock_logger, known_hashes):
        """Test that Hash dataclass is created during initialization."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)

            assert extractor.hash.md5 == known_hashes['md5']
            assert extractor.hash.sha1 == known_hashes['sha1']
            assert extractor.hash.sha256 == known_hashes['sha256']

    def test_extractor_binary_cached_property(self, elf_binary_path, mock_logger, elf_binary_content):
        """Test that binary content is loaded as cached property."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)

            # Access binary property
            binary = extractor.binary
            assert binary == elf_binary_content

            # Second access should return cached value (same id)
            assert extractor.binary is binary

    def test_extractor_with_exporters(self, elf_binary_path, mock_logger, mock_print_exporter):
        """Test extractor initialization with exporters."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                exporters=[mock_print_exporter]
            )

            assert len(extractor.exporters) == 1
            assert extractor.exporters[0] is mock_print_exporter

    def test_extractor_with_index_prefix(self, elf_binary_path, mock_logger):
        """Test extractor initialization with custom index prefix."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                index_prefix="custom_prefix"
            )

            assert "custom_prefix" in extractor.elastic_index

    def test_extractor_known_benign_flag(self, elf_binary_path, mock_logger):
        """Test extractor with known_benign flag."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                known_benign=True
            )

            assert extractor.known_benign is True
            assert extractor.known_malicious is False

    def test_extractor_known_malicious_flag(self, elf_binary_path, mock_logger):
        """Test extractor with known_malicious flag."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                known_malicious=True
            )

            assert extractor.known_benign is False
            assert extractor.known_malicious is True


class TestExtractorExportData:
    """Tests for export_data method."""

    def test_export_data_with_print_exporter(self, elf_binary_path, mock_logger, mock_print_exporter, capsys):
        """Test export_data with PrintExporter."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                exporters=[mock_print_exporter]
            )

            result = extractor.export_data()
            # Should succeed with PrintExporter
            assert result is True

    def test_export_data_no_exporters(self, elf_binary_path, mock_logger):
        """Test export_data with no exporters configured."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(
                elf_binary_path,
                mock_logger,
                exporters=[]
            )

            result = extractor.export_data()
            # Should succeed with no exporters (nothing to export)
            assert result is True


class TestExtractorEdgeCases:
    """Tests for edge cases in Extractor class."""

    def test_extractor_with_nonexistent_file(self, mock_logger):
        """Test extractor with non-existent file."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            with pytest.raises(FileNotFoundError):
                BasicPropertiesExtractor("/nonexistent/file.bin", mock_logger)

    def test_entropy_none_data(self, elf_binary_path, mock_logger):
        """Test entropy calculation with None returns 0."""
        from redb.extractors.basicproperties import BasicPropertiesExtractor

        with patch('redb.settings.ELASTIC_BINARIES_COLLECTION', 'test'):
            extractor = BasicPropertiesExtractor(elf_binary_path, mock_logger)
            result = extractor.calculate_entropy(None)
            assert result == 0.0

    def test_process_binary_string_high_bytes(self):
        """Test processing binary string with high byte values."""
        from redb.extractors.extractor import Extractor

        # Characters above 126 are non-printable
        input_bytes = b"\x7f\x80\x81\xff"
        result = Extractor.process_binary_string(input_bytes)
        assert "\\x7f" in result
        assert "\\x80" in result
        assert "\\xff" in result