- test_utils.py

# imports
import re

import pytest  # used for our unit tests
from pydantic.alias_generators import to_snake


# unit tests
def test_basic_conversions():
    # Simple camelCase
    assert to_snake("camelCase") == "camel_case"
    # Simple PascalCase
    assert to_snake("PascalCase") == "pascal_case"
    # Simple kebab-case
    assert to_snake("kebab-case") == "kebab_case"

def test_mixed_case_with_numbers():
    # camelCase with numbers
    assert to_snake("camelCase123") == "camel_case_123"
    # PascalCase with numbers
    assert to_snake("PascalCase123") == "pascal_case_123"
    # kebab-case with numbers
    assert to_snake("kebab-case-123") == "kebab_case_123"

def test_all_uppercase_acronyms():
    # PascalCase with acronyms
    assert to_snake("HTTPResponse") == "http_response"
    # camelCase with acronyms
    assert to_snake("httpResponse") == "http_response"

def test_multiple_consecutive_uppercase_letters():
    # PascalCase with multiple uppercase sequences
    assert to_snake("XMLHTTPRequest") == "xml_http_request"
    # camelCase with multiple uppercase sequences
    assert to_snake("xmlHTTPRequest") == "xml_http_request"

def test_edge_cases():
    # Single character input
    assert to_snake("a") == "a"
    assert to_snake("A") == "a"
    # All lowercase input
    assert to_snake("lowercase") == "lowercase"
    # All uppercase input
    assert to_snake("UPPERCASE") == "uppercase"
    # Empty string
    assert to_snake("") == ""
    # String with no letters
    assert to_snake("123") == "123"

def test_special_characters():
    # Input with special characters (should remain unchanged except for hyphens)
    assert to_snake("special!@#") == "special!@#"
    assert to_snake("kebab-case!@#") == "kebab_case!@#"

def test_hyphenated_words():
    # Multiple hyphens
    assert to_snake("multi-hyphen-case") == "multi_hyphen_case"
    # Leading and trailing hyphens
    assert to_snake("-leading-hyphen") == "_leading_hyphen"
    assert to_snake("trailing-hyphen-") == "trailing_hyphen_"

def test_mixed_case_with_special_characters():
    # PascalCase with special characters
    assert to_snake("PascalCase!@#") == "pascal_case!@#"
    # camelCase with special characters
    assert to_snake("camelCase!@#") == "camel_case!@#"
    # kebab-case with special characters
    assert to_snake("kebab-case!@#") == "kebab_case!@#"

def test_large_scale_test_cases():
    # Very long camelCase string
    assert to_snake("aVeryLongCamelCaseStringWith123Numbers") == "a_very_long_camel_case_string_with_123_numbers"
    # Very long PascalCase string
    assert to_snake("AVeryLongPascalCaseStringWith123Numbers") == "a_very_long_pascal_case_string_with_123_numbers"
    # Very long kebab-case string
    assert to_snake("a-very-long-kebab-case-string-with-123-numbers") == "a_very_long_kebab_case_string_with_123_numbers"

def test_complex_mixed_cases():
    # Complex mixed case with numbers and special characters
    assert to_snake("ComplexMixedCase123!@#") == "complex_mixed_case_123!@#"
    assert to_snake("complexMixedCase123!@#") == "complex_mixed_case_123!@#"
    assert to_snake("complex-mixed-case-123!@#") == "complex_mixed_case_123!@#"

def test_non_standard_characters():
    # Input with Unicode characters
    assert to_snake("PascalCaseÜnicode") == "pascal_case_ünicode"
    assert to_snake("camelCaseÜnicode") == "camel_case_ünicode"
    assert to_snake("kebab-case-ünicode") == "kebab_case_ünicode"

def test_mixed_separators():
    # Input with mixed separators (spaces, underscores, hyphens)
    assert to_snake("Pascal_Case-With Spaces") == "pascal_case_with_spaces"
    assert to_snake("camel_Case-With Spaces") == "camel_case_with_spaces"
    assert to_snake("kebab-case_with Spaces") == "kebab_case_with_spaces"

def test_leading_and_trailing_whitespace():
    # Input with leading and trailing whitespace
    assert to_snake(" PascalCase ") == " pascal_case "
    assert to_snake(" camelCase ") == " camel_case "
    assert to_snake(" kebab-case ") == " kebab_case "

def test_multiple_consecutive_separators():
    # Input with multiple consecutive separators
    assert to_snake("Pascal--Case") == "pascal__case"
    assert to_snake("camel--Case") == "camel__case"
    assert to_snake("kebab--case") == "kebab__case"

def test_empty_substrings():
    # Input with empty substrings between separators
    assert to_snake("Pascal--Case") == "pascal__case"
    assert to_snake("camel--Case") == "camel__case"
    assert to_snake("kebab--case") == "kebab__case"

def test_non_standard_casing():
    # Input with non-standard casing patterns
    assert to_snake("PascalCASE") == "pascal_case"
    assert to_snake("camelCASE") == "camel_case"
    assert to_snake("kebab-CASE") == "kebab_case"

def test_numbers_and_special_characters_mixed():
    # Input with numbers and special characters mixed within words
    assert to_snake("Pascal123Case!@#") == "pascal_123_case!@#"
    assert to_snake("camel123Case!@#") == "camel_123_case!@#"
    assert to_snake("kebab-123-case!@#") == "kebab_123_case!@#"

def test_single_character_separators():
    # Input with single character separators
    assert to_snake("Pascal-Case") == "pascal_case"
    assert to_snake("camel-Case") == "camel_case"
    assert to_snake("kebab-Case") == "kebab_case"

def test_repeated_characters():
    # Input with repeated characters
    assert to_snake("PascalCCase") == "pascal_c_case"
    assert to_snake("camelCCase") == "camel_c_case"
    assert to_snake("kebab-CCase") == "kebab_c_case"

def test_long_sequences_of_uppercase_letters():
    # Input with long sequences of uppercase letters
    assert to_snake("PascalCASEWithLongSequence") == "pascal_case_with_long_sequence"
    assert to_snake("camelCASEWithLongSequence") == "camel_case_with_long_sequence"
    assert to_snake("kebab-CASE-With-Long-Sequence") == "kebab_case_with_long_sequence"