diff --git a/html_to_django/converter.py b/html_to_django/converter.py
index 0d06237..f2a1322 100644
--- a/html_to_django/converter.py
+++ b/html_to_django/converter.py
@@ -47,6 +47,9 @@ def convert_file(path: str, overwrite: bool = False) -> None:
         path (str): The path to the HTML file to be converted.
         overwrite (bool, optional): Whether to overwrite the original file. Defaults to False.
     """
+    if not (os.path.exists(path) and os.path.isfile(path)):
+        raise FileNotFoundError
+
     with open(path, "r") as file:
         soup = bs4.BeautifulSoup(file, "html.parser")
 
@@ -75,6 +78,9 @@ def convert_dir(path: str, overwrite: bool = False) -> None:
         path (str): The path to the directory containing the HTML files to be converted.
         overwrite (bool, optional): Whether to overwrite the original files. Defaults to False.
     """
+    if not (os.path.exists(path) and os.path.isdir(path)):
+        raise FileNotFoundError
+
     for filepath in glob(f"{path}/**/*.html", recursive=True):
         convert_file(filepath, overwrite)
 
diff --git a/tests/test_project/something/other.html b/tests/test_project/something/other.html
new file mode 100644
index 0000000..435d58d
--- /dev/null
+++ b/tests/test_project/something/other.html
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en" dj-remove-default>
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Some Page</title>
+</head>
+<body>
+    <div>
+        <h2>Example</h2>
+        <p>This is an example Page</p>
+    </div>
+    <div>
+        <h2>List</h2>
+        <ul>
+            <li dj-for-wrap="i in items" dj-var="i.name" dj-style="background-color;i.bg_color;"></li>
+        </ul>
+    </div>
+</body>
+</html>
\ No newline at end of file
diff --git a/tests/test_project_expected_result/something/other.html b/tests/test_project_expected_result/something/other.html
new file mode 100644
index 0000000..1061ad3
--- /dev/null
+++ b/tests/test_project_expected_result/something/other.html
@@ -0,0 +1,20 @@
+<div>
+    <h2>
+        Example
+    </h2>
+    <p>
+        This is an example Page
+    </p>
+</div>
+<div>
+    <h2>
+        List
+    </h2>
+    <ul>
+        {% for i in items %}
+        <li style="background-color:{{ i.bg_color }};">
+            {{ i.name }}
+        </li>
+        {% endfor %}
+    </ul>
+</div>
diff --git a/tests/test_project_expected_result/test.n.html b/tests/test_project_expected_result/test.html
similarity index 100%
rename from tests/test_project_expected_result/test.n.html
rename to tests/test_project_expected_result/test.html
diff --git a/tests/tests_converter.py b/tests/tests_converter.py
index 29838a9..4642217 100644
--- a/tests/tests_converter.py
+++ b/tests/tests_converter.py
@@ -1,21 +1,119 @@
 import os
 import filecmp
 import shutil
+import tempfile
 from unittest import TestCase
-from html_to_django import converter
+from bs4 import BeautifulSoup
+from glob import glob
+from html_to_django.converter import get_required_libraries, convert_file, convert_dir
 
 
 class ConverterTests(TestCase):
+    def test_get_required_libraries(self) -> None:
+        html = '<div dj-libs="lib1;lib2">Content</div><div dj-libs="lib3"></div>'
+        soup = BeautifulSoup(html, 'html.parser')
+        expected = {'lib1', 'lib2', 'lib3'}
+        self.assertEqual(expected, get_required_libraries(soup))
+
+    def test_get_required_libraries_empty(self) -> None:
+        html = '<div>Content</div>'
+        soup = BeautifulSoup(html, 'html.parser')
+        expected: set[str] = set()
+        self.assertEqual(expected, get_required_libraries(soup))
+
     def test_convert_file(self) -> None:
-        shutil.copytree(
-            os.path.abspath("tests/test_project"),
-            os.path.abspath("tests/test_project_test_result"),
-            dirs_exist_ok=True
-        )
-        converter.convert_file(
-            os.path.abspath("tests/test_project_test_result/test.html")
-        )
-        self.assertTrue(filecmp.cmp(
-            os.path.abspath("tests/test_project_test_result/test.n.html"),
-            os.path.abspath("tests/test_project_expected_result/test.n.html")
-        ))
+        with tempfile.TemporaryDirectory() as tmpdir:
+            shutil.copytree(
+                "tests/test_project",
+                tmpdir,
+                dirs_exist_ok=True
+            )
+            convert_file(f"{tmpdir}/test.html")
+            # verify that the new file exists and has the expected value
+            self.assertTrue(filecmp.cmp(
+                "tests/test_project_expected_result/test.html",
+                f"{tmpdir}/test.n.html"
+            ))
+            # verify that the source file is unchanged
+            self.assertTrue(filecmp.cmp(
+                "tests/test_project/test.html",
+                f"{tmpdir}/test.html"
+            ))
+
+    def test_convert_file_overwrite(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            shutil.copytree(
+                "tests/test_project",
+                tmpdir,
+                dirs_exist_ok=True
+            )
+            convert_file(f"{tmpdir}/test.html", True)
+            # verify that the source file has been overwriten
+            self.assertTrue(filecmp.cmp(
+                "tests/test_project_expected_result/test.html",
+                f"{tmpdir}/test.html"
+            ))
+            # verify that no new file was created
+            self.assertFalse(os.path.exists(f"{tmpdir}/test.n.html"))
+
+    def test_convert_file_nonexistent(self) -> None:
+        with self.assertRaises(FileNotFoundError):
+            convert_file(os.path.abspath("tests/test/project/nonexistent_file.html"))
+
+    def test_convert_file_dir_passed(self) -> None:
+        with self.assertRaises(FileNotFoundError):
+            convert_file(os.path.abspath("tests/test_project"))
+
+    def test_convert_dir(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            shutil.copytree(
+                "tests/test_project",
+                tmpdir,
+                dirs_exist_ok=True
+            )
+            convert_dir(f"{tmpdir}")
+
+            for conversion_result in glob(f"{tmpdir}/**/*.n.html", recursive=True):
+                conversion_source = conversion_result.replace(".n.html", ".html")
+
+                # verify that the new file exists and has the expected value
+                expected_result = conversion_source.replace(tmpdir, "tests/test_project_expected_result")
+                self.assertTrue(filecmp.cmp(
+                    expected_result,
+                    conversion_result
+                ))
+
+                # verify that the source file is unchanged
+                original_source = conversion_source.replace(tmpdir, "tests/test_project")
+                self.assertTrue(filecmp.cmp(
+                    original_source,
+                    conversion_source
+                ))
+
+    def test_convert_dir_overwrite(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            shutil.copytree(
+                "tests/test_project",
+                tmpdir,
+                dirs_exist_ok=True
+            )
+            convert_dir(f"{tmpdir}", True)
+
+            for conversion_result in glob(f"{tmpdir}/**/*.html", recursive=True):
+                # verify that the source file has been overwritten
+                expected_result = conversion_result.replace(tmpdir, "tests/test_project_expected_result")
+                self.assertTrue(filecmp.cmp(
+                    expected_result,
+                    conversion_result
+                ))
+
+                # verify that no new file was created
+                self.assertFalse(os.path.exists(conversion_result.replace(".html", ".n.html")))
+
+    def test_convert_dir_nonexistent(self) -> None:
+        with self.assertRaises(FileNotFoundError):
+            convert_dir("tests/test_project/nonexistent_folder")
+
+    def test_convert_dir_file_passed(self) -> None:
+        with self.assertRaises(FileNotFoundError):
+            convert_dir("tests/test_project/test.html")