diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 00000000..55b033e9
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+pytest
\ No newline at end of file
diff --git a/src/array_flatten.py b/src/array_flatten.py
new file mode 100644
index 00000000..acdf2061
--- /dev/null
+++ b/src/array_flatten.py
@@ -0,0 +1,38 @@
+from typing import List, Union, Any
+
+def flatten_array(arr: List[Union[Any, List]]) -> List[Any]:
+    """
+    Recursively flatten a nested list into a single-level list.
+    
+    Args:
+        arr (List[Union[Any, List]]): A potentially nested list to be flattened.
+    
+    Returns:
+        List[Any]: A flattened list containing all non-list elements.
+    
+    Raises:
+        TypeError: If the input is not a list.
+    
+    Examples:
+        >>> flatten_array([1, [2, 3], [4, [5, 6]]])
+        [1, 2, 3, 4, 5, 6]
+        >>> flatten_array([1, 2, 3])
+        [1, 2, 3]
+        >>> flatten_array([])
+        []
+    """
+    # Check if input is a list
+    if not isinstance(arr, list):
+        raise TypeError("Input must be a list")
+    
+    # Use a single-pass flattening approach
+    flattened = []
+    for item in arr:
+        # If the item is a list, recursively flatten it
+        if isinstance(item, list):
+            flattened.extend(flatten_array(item))
+        else:
+            # If not a list, append directly
+            flattened.append(item)
+    
+    return flattened
\ No newline at end of file
diff --git a/src/binary_search.py b/src/binary_search.py
new file mode 100644
index 00000000..4023b2fa
--- /dev/null
+++ b/src/binary_search.py
@@ -0,0 +1,48 @@
+def binary_search(arr, target):
+    """
+    Perform binary search on a sorted array to find the target element.
+    
+    Args:
+        arr (list): A sorted list of comparable elements 
+        target: The element to search for
+    
+    Returns:
+        int: Index of the target element if found, otherwise -1
+    
+    Raises:
+        TypeError: If input is not a list
+        ValueError: If the input list is not sorted
+    """
+    # Check if input is a list
+    if not isinstance(arr, list):
+        raise TypeError("Input must be a list")
+    
+    # Check if list is sorted 
+    if arr != sorted(arr):
+        raise ValueError("Input list must be sorted in ascending order")
+    
+    # Handle empty list case
+    if not arr:
+        return -1
+    
+    # Standard binary search implementation
+    left, right = 0, len(arr) - 1
+    
+    while left <= right:
+        # Calculate midpoint to avoid potential integer overflow
+        mid = left + (right - left) // 2
+        
+        # Check if target is found
+        if arr[mid] == target:
+            return mid
+        
+        # If target is less than mid, search left half
+        elif arr[mid] > target:
+            right = mid - 1
+        
+        # If target is greater than mid, search right half
+        else:
+            left = mid + 1
+    
+    # Target not found
+    return -1
\ No newline at end of file
diff --git a/src/rgb_to_hex.py b/src/rgb_to_hex.py
new file mode 100644
index 00000000..1980275b
--- /dev/null
+++ b/src/rgb_to_hex.py
@@ -0,0 +1,24 @@
+def rgb_to_hex(r: int, g: int, b: int) -> str:
+    """
+    Convert RGB color values to a hexadecimal color code.
+
+    Args:
+        r (int): Red color value (0-255)
+        g (int): Green color value (0-255)
+        b (int): Blue color value (0-255)
+
+    Returns:
+        str: Hexadecimal color code (e.g., '#FF0000')
+
+    Raises:
+        ValueError: If any color value is not in the range 0-255
+    """
+    # Validate input values
+    for color, name in [(r, 'Red'), (g, 'Green'), (b, 'Blue')]:
+        if not isinstance(color, int):
+            raise TypeError(f"{name} value must be an integer")
+        if color < 0 or color > 255:
+            raise ValueError(f"{name} value must be between 0 and 255")
+
+    # Convert RGB to hex, ensuring two-digit representation
+    return f'#{r:02X}{g:02X}{b:02X}'
\ No newline at end of file
diff --git a/src/string_reversal.py b/src/string_reversal.py
new file mode 100644
index 00000000..7d91c690
--- /dev/null
+++ b/src/string_reversal.py
@@ -0,0 +1,24 @@
+def reverse_string(s: str) -> str:
+    """
+    Reverse the given string manually, preserving all characters.
+
+    Args:
+        s (str): The input string to be reversed.
+
+    Returns:
+        str: The reversed string.
+
+    Raises:
+        TypeError: If the input is not a string.
+    """
+    # Type checking
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+    
+    # Manual string reversal using a list-based approach
+    # This preserves all characters including spaces and special characters
+    reversed_chars = []
+    for i in range(len(s) - 1, -1, -1):
+        reversed_chars.append(s[i])
+    
+    return ''.join(reversed_chars)
\ No newline at end of file
diff --git a/src/url_parser.py b/src/url_parser.py
new file mode 100644
index 00000000..0440071c
--- /dev/null
+++ b/src/url_parser.py
@@ -0,0 +1,59 @@
+from urllib.parse import urlparse, parse_qs
+from typing import Dict, Any, Optional
+
+def parse_url(url: str) -> Dict[str, Any]:
+    """
+    Parse a given URL into its component parts.
+    
+    Args:
+        url (str): The URL to parse
+    
+    Returns:
+        Dict[str, Any]: A dictionary containing parsed URL components
+    
+    Raises:
+        ValueError: If the URL is invalid or empty
+    """
+    # Check for empty or None input
+    if not url or not isinstance(url, str):
+        raise ValueError("Invalid URL: URL must be a non-empty string")
+    
+    try:
+        # Use urlparse to break down the URL
+        parsed_url = urlparse(url)
+        
+        # Prepare the result dictionary
+        result = {
+            'scheme': parsed_url.scheme,
+            'netloc': parsed_url.netloc,
+            'path': parsed_url.path,
+            'params': parsed_url.params,
+            'query': parse_qs(parsed_url.query),
+            'fragment': parsed_url.fragment
+        }
+        
+        # Extract additional useful information
+        # Handle credentials first
+        if '@' in parsed_url.netloc:
+            credentials, host = parsed_url.netloc.split('@', 1)
+            if ':' in credentials:
+                result['username'], result['password'] = credentials.split(':', 1)
+            else:
+                result['username'] = credentials
+            
+            # Update netloc to only include host
+            parsed_url = parsed_url._replace(netloc=host)
+        
+        # Split host and port
+        if ':' in parsed_url.netloc:
+            hostname_port = parsed_url.netloc.split(':')
+            result['hostname'] = hostname_port[0]
+            if len(hostname_port) > 1:
+                result['port'] = hostname_port[1]
+        else:
+            result['hostname'] = parsed_url.netloc
+        
+        return result
+    
+    except Exception as e:
+        raise ValueError(f"Error parsing URL: {str(e)}")
\ No newline at end of file
diff --git a/tests/test_array_flatten.py b/tests/test_array_flatten.py
new file mode 100644
index 00000000..90032cfa
--- /dev/null
+++ b/tests/test_array_flatten.py
@@ -0,0 +1,38 @@
+import pytest
+from src.array_flatten import flatten_array
+
+def test_flatten_simple_list():
+    """Test flattening a simple list."""
+    assert flatten_array([1, 2, 3]) == [1, 2, 3]
+
+def test_flatten_nested_list():
+    """Test flattening a nested list."""
+    assert flatten_array([1, [2, 3], [4, [5, 6]]]) == [1, 2, 3, 4, 5, 6]
+
+def test_flatten_empty_list():
+    """Test flattening an empty list."""
+    assert flatten_array([]) == []
+
+def test_flatten_deeply_nested_list():
+    """Test flattening a deeply nested list."""
+    assert flatten_array([1, [2, [3, [4]]], 5]) == [1, 2, 3, 4, 5]
+
+def test_flatten_mixed_types_list():
+    """Test flattening a list with mixed types."""
+    assert flatten_array([1, 'a', [2, 'b'], [3, [4, 'c']]]) == [1, 'a', 2, 'b', 3, 4, 'c']
+
+def test_invalid_input_type():
+    """Test that a TypeError is raised for non-list inputs."""
+    with pytest.raises(TypeError, match="Input must be a list"):
+        flatten_array("not a list")
+    
+    with pytest.raises(TypeError, match="Input must be a list"):
+        flatten_array(123)
+
+def test_nested_empty_lists():
+    """Test flattening a list with nested empty lists."""
+    assert flatten_array([1, [], [2, []], 3]) == [1, 2, 3]
+
+def test_single_element_nested_list():
+    """Test flattening a list with single-element nested lists."""
+    assert flatten_array([[1], [2], [3]]) == [1, 2, 3]
\ No newline at end of file
diff --git a/tests/test_binary_search.py b/tests/test_binary_search.py
new file mode 100644
index 00000000..9203e336
--- /dev/null
+++ b/tests/test_binary_search.py
@@ -0,0 +1,49 @@
+import pytest
+from src.binary_search import binary_search
+
+def test_binary_search_basic():
+    """Test basic functionality of binary search"""
+    arr = [1, 3, 5, 7, 9, 11, 13]
+    assert binary_search(arr, 7) == 3
+    assert binary_search(arr, 13) == 6
+    assert binary_search(arr, 1) == 0
+
+def test_binary_search_not_found():
+    """Test when target is not in the list"""
+    arr = [1, 3, 5, 7, 9, 11, 13]
+    assert binary_search(arr, 4) == -1
+    assert binary_search(arr, 0) == -1
+    assert binary_search(arr, 14) == -1
+
+def test_binary_search_empty_list():
+    """Test binary search on an empty list"""
+    assert binary_search([], 5) == -1
+
+def test_binary_search_single_element():
+    """Test binary search on single-element list"""
+    assert binary_search([5], 5) == 0
+    assert binary_search([5], 6) == -1
+
+def test_binary_search_invalid_input():
+    """Test error handling for invalid inputs"""
+    with pytest.raises(TypeError, match="Input must be a list"):
+        binary_search("not a list", 5)
+    
+    with pytest.raises(ValueError, match="Input list must be sorted in ascending order"):
+        binary_search([5, 3, 1], 3)
+
+def test_binary_search_large_list():
+    """Test binary search on a larger sorted list"""
+    arr = list(range(1000))
+    assert binary_search(arr, 500) == 500
+    assert binary_search(arr, 999) == 999
+    assert binary_search(arr, 1000) == -1
+
+def test_binary_search_duplicates():
+    """Test binary search with a list containing duplicates"""
+    arr = [1, 2, 2, 3, 3, 3, 4, 4, 5]
+    # Note: This will return the index of one of the duplicate elements
+    assert binary_search(arr, 3) in [4, 5, 6]
+    assert binary_search(arr, 2) in [1, 2]
+    assert binary_search(arr, 1) == 0
+    assert binary_search(arr, 5) == 8
\ No newline at end of file
diff --git a/tests/test_rgb_to_hex.py b/tests/test_rgb_to_hex.py
new file mode 100644
index 00000000..08fbd30c
--- /dev/null
+++ b/tests/test_rgb_to_hex.py
@@ -0,0 +1,51 @@
+import pytest
+from src.rgb_to_hex import rgb_to_hex
+
+def test_basic_conversion():
+    """Test basic RGB to hex conversion"""
+    assert rgb_to_hex(255, 0, 0) == '#FF0000'  # Red
+    assert rgb_to_hex(0, 255, 0) == '#00FF00'  # Green
+    assert rgb_to_hex(0, 0, 255) == '#0000FF'  # Blue
+    assert rgb_to_hex(255, 255, 255) == '#FFFFFF'  # White
+    assert rgb_to_hex(0, 0, 0) == '#000000'  # Black
+
+def test_mixed_colors():
+    """Test mixed color conversions"""
+    assert rgb_to_hex(128, 128, 128) == '#808080'  # Gray
+    assert rgb_to_hex(255, 165, 0) == '#FFA500'  # Orange
+
+def test_zero_values():
+    """Test conversion with zero values"""
+    assert rgb_to_hex(0, 0, 0) == '#000000'
+
+def test_boundary_values():
+    """Test boundary values"""
+    assert rgb_to_hex(0, 0, 0) == '#000000'
+    assert rgb_to_hex(255, 255, 255) == '#FFFFFF'
+
+def test_invalid_low_values():
+    """Test error handling for values below 0"""
+    with pytest.raises(ValueError, match="Red value must be between 0 and 255"):
+        rgb_to_hex(-1, 0, 0)
+    with pytest.raises(ValueError, match="Green value must be between 0 and 255"):
+        rgb_to_hex(0, -1, 0)
+    with pytest.raises(ValueError, match="Blue value must be between 0 and 255"):
+        rgb_to_hex(0, 0, -1)
+
+def test_invalid_high_values():
+    """Test error handling for values above 255"""
+    with pytest.raises(ValueError, match="Red value must be between 0 and 255"):
+        rgb_to_hex(256, 0, 0)
+    with pytest.raises(ValueError, match="Green value must be between 0 and 255"):
+        rgb_to_hex(0, 256, 0)
+    with pytest.raises(ValueError, match="Blue value must be between 0 and 255"):
+        rgb_to_hex(0, 0, 256)
+
+def test_invalid_type():
+    """Test error handling for non-integer inputs"""
+    with pytest.raises(TypeError, match="Red value must be an integer"):
+        rgb_to_hex('255', 0, 0)
+    with pytest.raises(TypeError, match="Green value must be an integer"):
+        rgb_to_hex(0, '255', 0)
+    with pytest.raises(TypeError, match="Blue value must be an integer"):
+        rgb_to_hex(0, 0, '255')
\ No newline at end of file
diff --git a/tests/test_string_reversal.py b/tests/test_string_reversal.py
new file mode 100644
index 00000000..98f56ed7
--- /dev/null
+++ b/tests/test_string_reversal.py
@@ -0,0 +1,48 @@
+import pytest
+from src.string_reversal import reverse_string
+
+def test_reverse_string_basic():
+    """Test basic string reversal."""
+    assert reverse_string("hello") == "olleh"
+    assert reverse_string("python") == "nohtyp"
+
+def test_reverse_string_empty():
+    """Test reversal of an empty string."""
+    assert reverse_string("") == ""
+
+def test_reverse_string_single_char():
+    """Test reversal of a single character."""
+    assert reverse_string("a") == "a"
+
+def test_reverse_string_with_spaces():
+    """Test string reversal preserves spaces."""
+    assert reverse_string("hello world") == "dlrow olleh"
+
+def test_reverse_string_with_special_chars():
+    """Test string reversal with special characters."""
+    assert reverse_string("a!b@c#") == "#c@b!a"
+
+def test_reverse_string_invalid_input():
+    """Test that TypeError is raised for non-string input."""
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(123)
+    
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(None)
+
+def test_reverse_string_unicode():
+    """Test reversal of Unicode strings."""
+    assert reverse_string("こんにちは") == "はちにんこ"
+
+def test_implementation_method():
+    """Ensure the implementation does not use slice notation or reverse()."""
+    import inspect
+    import src.string_reversal
+    
+    # Get the source code of the function
+    source_lines = inspect.getsource(src.string_reversal.reverse_string)
+    source_code = ''.join(source_lines)
+    
+    # Check that forbidden methods are not used
+    assert '[::-1]' not in source_code, "Do not use slice notation for reversal"
+    assert '.reverse()' not in source_code, "Do not use built-in reverse() method"
\ No newline at end of file
diff --git a/tests/test_url_parser.py b/tests/test_url_parser.py
new file mode 100644
index 00000000..8fba9efc
--- /dev/null
+++ b/tests/test_url_parser.py
@@ -0,0 +1,64 @@
+import pytest
+from src.url_parser import parse_url
+
+def test_basic_url_parsing():
+    """Test parsing a basic URL"""
+    url = "https://www.example.com/path/to/page"
+    result = parse_url(url)
+    assert result['scheme'] == 'https'
+    assert result['hostname'] == 'www.example.com'
+    assert result['path'] == '/path/to/page'
+
+def test_url_with_query_params():
+    """Test parsing URL with query parameters"""
+    url = "https://example.com/search?q=python&category=programming"
+    result = parse_url(url)
+    assert result['scheme'] == 'https'
+    assert result['query'] == {'q': ['python'], 'category': ['programming']}
+
+def test_url_with_port():
+    """Test parsing URL with port number"""
+    url = "http://localhost:8080/api"
+    result = parse_url(url)
+    assert result['scheme'] == 'http'
+    assert result['hostname'] == 'localhost'
+    assert result['port'] == '8080'
+    assert result['path'] == '/api'
+
+def test_url_with_credentials():
+    """Test parsing URL with username and password"""
+    url = "https://username:password@example.com/private"
+    result = parse_url(url)
+    assert result['username'] == 'username'
+    assert result['password'] == 'password'
+    assert result['hostname'] == 'example.com'
+    assert result['path'] == '/private'
+
+def test_url_with_fragment():
+    """Test parsing URL with fragment"""
+    url = "https://docs.example.com/page#section1"
+    result = parse_url(url)
+    assert result['fragment'] == 'section1'
+
+def test_invalid_url_empty():
+    """Test handling of empty URL"""
+    with pytest.raises(ValueError, match="Invalid URL"):
+        parse_url("")
+
+def test_invalid_url_none():
+    """Test handling of None input"""
+    with pytest.raises(ValueError, match="Invalid URL"):
+        parse_url(None)
+
+def test_complex_url():
+    """Test parsing a complex URL with multiple components"""
+    url = "https://user:pass@example.com:8443/path/to/resource?key1=value1&key2=value2#fragment"
+    result = parse_url(url)
+    assert result['scheme'] == 'https'
+    assert result['username'] == 'user'
+    assert result['password'] == 'pass'
+    assert result['hostname'] == 'example.com'
+    assert result['port'] == '8443'
+    assert result['path'] == '/path/to/resource'
+    assert result['query'] == {'key1': ['value1'], 'key2': ['value2']}
+    assert result['fragment'] == 'fragment'
\ No newline at end of file