diff --git a/.flake8 b/.flake8
index f837320..ec8536f 100644
--- a/.flake8
+++ b/.flake8
@@ -1,3 +1,3 @@
 [flake8]
 max-line-length = 120
-exclude = dist
\ No newline at end of file
+exclude = dist, tests
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0dafe46..d193446 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,7 @@ name: CI
 on: [push, pull_request]
 
 jobs:
-  build-and-lint:
+  all:
     runs-on: ubuntu-latest
 
     strategy:
@@ -22,12 +22,15 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8
+        pip install flake8 pytest
         pip install -r requirements.txt
 
     - name: Build project
       run: make
 
+    - name: Test probe
+      run: pytest
+
     - name: Lint with flake8
       run: flake8 .
 
diff --git a/.gitignore b/.gitignore
index bdaa5ea..4bf1bd5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.tar.gz
-.idea
\ No newline at end of file
+.idea
+__pycache__/
\ No newline at end of file
diff --git a/check_b2access.py b/check_b2access.py
index cbe355e..3cae32a 100755
--- a/check_b2access.py
+++ b/check_b2access.py
@@ -40,7 +40,9 @@ def wrapper(*args, **kwargs):
                 print(message, sys.exc_info()[0])
                 sys.exit(2)
             return ret
+
         return wrapper
+
     return handleExceptions
 
 
@@ -63,8 +65,8 @@ def getAccessToken(param):
         if param.verbose:
             print("Access token: " + k['access_token'])
 
-        getTokenInfo(str(param.url) + '/oauth2/tokeninfo', str(k['access_token']), param.verbose)
-        getUserInfo(str(param.url) + '/oauth2/userinfo', str(k['access_token']), param.verbose)
+        getTokenInfo(f"{str(param.url)}/oauth2/tokeninfo{str(k['access_token'])}", param.verbose)
+        getUserInfo(f"{str(param.url)}/oauth2/userinfo{str(k['access_token'])}", param.verbose)
     except ConnectionError as e:
         print("CRITICAL: Invalid Unity URL: {0}".format(e))
         sys.exit(2)
@@ -84,6 +86,8 @@ def getTokenInfo(url, token, verbose):
             print(f"\nFetching access token information from URL: {url}")
 
         entity = requests.get(url, verify=False, headers={'Authorization': 'Bearer ' + token})
+        if entity.status_code != 200:
+            raise ConnectionError(f"Fetching access token from {url} returned {entity.status_code}")
         j = entity.json()
         expire = datetime.datetime.fromtimestamp(int(j['exp'])).strftime('%Y-%m-%d %H:%M:%S')
         if verbose:
@@ -103,11 +107,13 @@ def getTokenInfo(url, token, verbose):
 def getUserInfo(url, token, verbose):
     """ Fetch user information using access token """
     try:
-        if parser_args.verbose:
+        if verbose:
             print(f"\nFetching user information based on access token, endpoint URL: {url}")
         entity = requests.get(url, verify=False, headers={'Authorization': 'Bearer ' + token})
+        if entity.status_code != 200:
+            raise ConnectionError(f"Fetching access token from {url} returned {entity.status_code}")
         j = entity.json()
-        if parser_args.verbose:
+        if verbose:
             print(
                 f"Subject: {j['sub']}\nPersistent Id: {j['unity:persistent']}\n\
                 Detailed user information: {entity.text}")
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..84ad2d4
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,6 @@
+[pytest]
+minversion = 6.0
+addopts = -ra -q
+testpaths =
+    tests
+pythonpath = .
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 65d2f78..dc94277 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,4 +2,6 @@ oauthlib
 requests-oauthlib
 urllib3
 validators
-requests
\ No newline at end of file
+requests
+pytest
+requests-mock
\ No newline at end of file
diff --git a/tests/test_check_b2access.py b/tests/test_check_b2access.py
new file mode 100644
index 0000000..1cabfeb
--- /dev/null
+++ b/tests/test_check_b2access.py
@@ -0,0 +1,46 @@
+import json
+
+import pytest
+from requests import Response
+
+from check_b2access import getAccessToken, getLdapName, getInfoCert, getTokenInfo, getUserInfo, getInfoUsernamePassword
+import requests_mock
+
+
+class TestProbe:
+    def test_get_ldap_name(self):
+        name = getLdapName("Apple/Pineapple/Banana  ")
+        assert name == "Banana,Pineapple"
+        name = getLdapName("Apple/Pineapple/Banana/Oranges  ")
+        assert name == "Oranges,Banana,Pineapple"
+
+    def test_get_user_info(self):
+        url = "https://some_url"
+        token = "token"
+
+        body = json.loads(
+            """{
+            "sub": "subject",
+            "unity:persistent": "PersistentID"
+            }
+            """
+        )
+
+        with requests_mock.Mocker() as m:
+            m.get(url, json=body, status_code=200)
+            getUserInfo(url, token, True)
+
+    @pytest.mark.parametrize("status_code, body", [
+        [200, '{"sub": "subject"}'],  # missing persistent ID
+        [200, '{"unity:persistent": "PersistentID"}'],  # missing subject
+        [500, '{"sub": "subject", "unity:persistent": "PersistentID"}']  # Server Error
+    ])
+    def test_get_user_info_exception(self, status_code, body):
+        body = json.loads(body)
+        url = "https://some_url"
+        token = "token"
+
+        with pytest.raises(SystemExit) as e:
+            with requests_mock.Mocker() as m:
+                m.get(url, json=body, status_code=status_code)
+                getUserInfo(url, token, True)