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_flattener.py b/src/array_flattener.py
new file mode 100644
index 00000000..c7196377
--- /dev/null
+++ b/src/array_flattener.py
@@ -0,0 +1,39 @@
+from typing import List, Union
+
+def flatten_array(arr: List[Union[int, List]]) -> List[int]:
+    """
+    Recursively flatten a nested list of integers into a single-level list.
+    
+    Args:
+        arr (List[Union[int, List]]): A potentially nested list of integers.
+    
+    Returns:
+        List[int]: A flattened list containing all integers from the input.
+    
+    Raises:
+        TypeError: If the input is not a list or contains non-integer/non-list elements.
+    
+    Examples:
+        >>> flatten_array([1, [2, 3], 4])
+        [1, 2, 3, 4]
+        >>> flatten_array([1, [2, [3, 4]], 5])
+        [1, 2, 3, 4, 5]
+    """
+    # Validate input is a list
+    if not isinstance(arr, list):
+        raise TypeError("Input must be a list")
+    
+    flattened = []
+    
+    for item in arr:
+        # If item is a list, recursively flatten
+        if isinstance(item, list):
+            flattened.extend(flatten_array(item))
+        # If item is an integer, append to result
+        elif isinstance(item, int):
+            flattened.append(item)
+        # Raise error for invalid item types
+        else:
+            raise TypeError(f"List can only contain integers or nested lists, found {type(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..abbb6ed1
--- /dev/null
+++ b/src/binary_search.py
@@ -0,0 +1,46 @@
+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 (ascending order)
+        target: The element to search for
+    
+    Returns:
+        int: Index of the target element if found, -1 otherwise
+    
+    Raises:
+        TypeError: If input is not a list
+        ValueError: If the input list is not sorted
+    """
+    # Validate input
+    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")
+    
+    # Edge case: empty list
+    if not arr:
+        return -1
+    
+    # Binary search implementation
+    left, right = 0, len(arr) - 1
+    
+    while left <= right:
+        # Prevent potential integer overflow
+        mid = left + (right - left) // 2
+        
+        # Check if target is found
+        if arr[mid] == target:
+            return mid
+        
+        # Decide which half to search
+        if arr[mid] < target:
+            left = mid + 1
+        else:
+            right = 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..eccce1b6
--- /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 representation.
+    
+    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 representation (e.g., '#FF0000')
+    
+    Raises:
+        ValueError: If any color value is outside the valid range of 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..6deabbf8
--- /dev/null
+++ b/src/string_reversal.py
@@ -0,0 +1,31 @@
+def reverse_string(s: str) -> str:
+    """
+    Reverse the given string manually without using slicing or reverse().
+    
+    Args:
+        s (str): The input string to be reversed.
+    
+    Returns:
+        str: The reversed string.
+    
+    Raises:
+        TypeError: If the input is not a string.
+    """
+    # Check if input is a string
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+    
+    # Convert string to list of characters
+    chars = list(s)
+    
+    # Manually reverse the list of characters
+    left, right = 0, len(chars) - 1
+    while left < right:
+        # Swap characters
+        chars[left], chars[right] = chars[right], chars[left]
+        # Move towards the center
+        left += 1
+        right -= 1
+    
+    # Convert back to string and return
+    return ''.join(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..2b4957ab
--- /dev/null
+++ b/src/url_parser.py
@@ -0,0 +1,74 @@
+from urllib.parse import urlparse, parse_qs
+from typing import Dict, Any
+
+def parse_url(url: str) -> Dict[str, Any]:
+    """
+    Parse a given URL into its component parts.
+
+    Args:
+        url (str): The URL to be parsed.
+
+    Returns:
+        Dict[str, Any]: A dictionary containing parsed URL components:
+        - protocol: The URL scheme (e.g., 'http', 'https')
+        - domain: The domain name
+        - port: The port number (or None if not specified)
+        - path: The path component of the URL
+        - query_params: A dictionary of query parameters
+        - fragment: The fragment identifier (or None if not present)
+
+    Raises:
+        ValueError: If the input is not a valid URL string.
+    """
+    # Validate input
+    if not isinstance(url, str):
+        raise ValueError("Input must be a string")
+    
+    # Handle empty or whitespace-only strings
+    if not url.strip():
+        raise ValueError("URL cannot be empty")
+
+    try:
+        # Validate basic structure of the URL
+        if not any(char in url for char in ['/', '.', ':']):
+            raise ValueError(f"Invalid URL: {url}")
+
+        # Try parsing with potential manual protocol handling
+        if '://' not in url:
+            # If the URL contains path, treat it as a potential http URL
+            if '/' in url:
+                # If there's a path, try http:// 
+                parsed_url = urlparse('http://' + url)
+                protocol = None
+            else:
+                # If just a domain, try http://
+                parsed_url = urlparse('http://' + url)
+                protocol = None
+        else:
+            # If protocol is present, use as-is
+            parsed_url = urlparse(url)
+            protocol = parsed_url.scheme
+        
+        # Extract query parameters
+        query_params = parse_qs(parsed_url.query)
+        # Convert query params to their single values if possible
+        query_params = {k: v[0] if len(v) == 1 else v for k, v in query_params.items()}
+
+        # Determine path
+        path = parsed_url.path if parsed_url.path and parsed_url.path != '/' else None
+
+        # Ensure path starts with '/' if present
+        if path and not path.startswith('/'):
+            path = '/' + path
+
+        # Construct the result dictionary
+        return {
+            'protocol': protocol,
+            'domain': parsed_url.hostname,
+            'port': parsed_url.port,
+            'path': path,
+            'query_params': query_params,
+            'fragment': parsed_url.fragment or None
+        }
+    except Exception:
+        raise ValueError(f"Invalid URL: {url}")
\ No newline at end of file
diff --git a/tests/test_array_flattener.py b/tests/test_array_flattener.py
new file mode 100644
index 00000000..1c12928b
--- /dev/null
+++ b/tests/test_array_flattener.py
@@ -0,0 +1,46 @@
+import pytest
+from src.array_flattener import flatten_array
+
+def test_flatten_simple_list():
+    """Test flattening a simple list with no nested lists"""
+    assert flatten_array([1, 2, 3]) == [1, 2, 3]
+
+def test_flatten_single_nested_list():
+    """Test flattening a list with one level of nesting"""
+    assert flatten_array([1, [2, 3], 4]) == [1, 2, 3, 4]
+
+def test_flatten_multiple_nested_lists():
+    """Test flattening a list with multiple levels of nesting"""
+    assert flatten_array([1, [2, [3, 4]], 5]) == [1, 2, 3, 4, 5]
+
+def test_flatten_deeply_nested_list():
+    """Test flattening a deeply 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_nested_empty_lists():
+    """Test flattening a list with nested empty lists"""
+    assert flatten_array([1, [], [2, []], 3]) == [1, 2, 3]
+
+def test_invalid_input_non_list():
+    """Test that a TypeError is raised for non-list input"""
+    with pytest.raises(TypeError, match="Input must be a list"):
+        flatten_array(123)
+
+def test_invalid_input_non_integer_element():
+    """Test that a TypeError is raised for non-integer/non-list elements"""
+    with pytest.raises(TypeError):
+        flatten_array([1, 2, "3"])
+    with pytest.raises(TypeError):
+        flatten_array([1, [2, 3.14], 4])
+
+def test_flatten_single_element_list():
+    """Test flattening a list with a single element"""
+    assert flatten_array([42]) == [42]
+
+def test_flatten_list_with_single_nested_list():
+    """Test flattening a list containing a single nested list"""
+    assert flatten_array([[1]]) == [1]
\ 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..4f35522e
--- /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_normal_case():
+    """Test binary search with a typical sorted list."""
+    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."""
+    arr = []
+    assert binary_search(arr, 5) == -1
+
+def test_binary_search_single_element():
+    """Test binary search on a single-element list."""
+    arr = [5]
+    assert binary_search(arr, 5) == 0
+    assert binary_search(arr, 6) == -1
+
+def test_binary_search_invalid_input():
+    """Test error handling for invalid inputs."""
+    with pytest.raises(TypeError):
+        binary_search("not a list", 5)
+    
+    with pytest.raises(ValueError):
+        binary_search([5, 3, 1], 3)  # Unsorted list
+
+def test_binary_search_duplicate_elements():
+    """Test binary search with duplicate elements."""
+    arr = [1, 2, 2, 3, 3, 3, 4, 4, 5]
+    # Note: This returns 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]
+
+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
\ 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..3cde58df
--- /dev/null
+++ b/tests/test_rgb_to_hex.py
@@ -0,0 +1,53 @@
+import pytest
+from src.rgb_to_hex import rgb_to_hex
+
+def test_rgb_to_hex_basic():
+    """Test basic color 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_rgb_to_hex_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_rgb_to_hex_boundary_values():
+    """Test boundary values"""
+    assert rgb_to_hex(0, 0, 0) == '#000000'
+    assert rgb_to_hex(255, 255, 255) == '#FFFFFF'
+
+def test_rgb_to_hex_invalid_inputs():
+    """Test error handling for invalid inputs"""
+    # Test negative values
+    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)
+    
+    # Test values over 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_rgb_to_hex_type_errors():
+    """Test type checking"""
+    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..f7a51634
--- /dev/null
+++ b/tests/test_string_reversal.py
@@ -0,0 +1,34 @@
+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 reversing an empty string."""
+    assert reverse_string("") == ""
+
+def test_reverse_string_single_char():
+    """Test reversing a single character."""
+    assert reverse_string("a") == "a"
+
+def test_reverse_string_with_spaces():
+    """Test reversing a string with spaces."""
+    assert reverse_string("hello world") == "dlrow olleh"
+
+def test_reverse_string_with_special_chars():
+    """Test reversing a string with special characters."""
+    assert reverse_string("a!b@c#") == "#c@b!a"
+
+def test_reverse_string_invalid_input():
+    """Test that a TypeError is raised for non-string inputs."""
+    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)
+    
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(["list"])
\ 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..a8c26628
--- /dev/null
+++ b/tests/test_url_parser.py
@@ -0,0 +1,83 @@
+import pytest
+from src.url_parser import parse_url
+
+def test_complete_url():
+    """Test parsing a complete URL with all components."""
+    url = "https://www.example.com:8080/path/to/page?key1=value1&key2=value2#section"
+    result = parse_url(url)
+    
+    assert result == {
+        'protocol': 'https',
+        'domain': 'www.example.com',
+        'port': 8080,
+        'path': '/path/to/page',
+        'query_params': {'key1': 'value1', 'key2': 'value2'},
+        'fragment': 'section'
+    }
+
+def test_minimal_url():
+    """Test parsing a minimal URL with just protocol and domain."""
+    url = "http://example.com"
+    result = parse_url(url)
+    
+    assert result == {
+        'protocol': 'http',
+        'domain': 'example.com',
+        'port': None,
+        'path': None,
+        'query_params': {},
+        'fragment': None
+    }
+
+def test_url_with_multiple_query_params():
+    """Test URL with multiple query parameters."""
+    url = "https://example.com/search?q=test&category=books&sort=relevance"
+    result = parse_url(url)
+    
+    assert result == {
+        'protocol': 'https',
+        'domain': 'example.com',
+        'port': None,
+        'path': '/search',
+        'query_params': {
+            'q': 'test', 
+            'category': 'books', 
+            'sort': 'relevance'
+        },
+        'fragment': None
+    }
+
+def test_url_with_no_protocol():
+    """Test URL without a protocol."""
+    url = "example.com/path"
+    result = parse_url(url)
+    
+    assert result == {
+        'protocol': None,
+        'domain': 'example.com',
+        'port': None,
+        'path': '/path',
+        'query_params': {},
+        'fragment': None
+    }
+
+def test_invalid_input_types():
+    """Test error handling for invalid input types."""
+    with pytest.raises(ValueError, match="Input must be a string"):
+        parse_url(123)
+    
+    with pytest.raises(ValueError, match="Input must be a string"):
+        parse_url(None)
+
+def test_empty_string():
+    """Test error handling for empty or whitespace-only strings."""
+    with pytest.raises(ValueError, match="URL cannot be empty"):
+        parse_url("")
+    
+    with pytest.raises(ValueError, match="URL cannot be empty"):
+        parse_url("   ")
+
+def test_invalid_url():
+    """Test error handling for clearly invalid URLs."""
+    with pytest.raises(ValueError, match="Invalid URL"):
+        parse_url("not a valid url")
\ No newline at end of file