diff --git a/.github/workflows/linux-tests.yml b/.github/workflows/linux-tests.yml
new file mode 100644
index 0000000..e34cc2d
--- /dev/null
+++ b/.github/workflows/linux-tests.yml
@@ -0,0 +1,26 @@
+name: Linux
+
+on: [push, pull_request]
+
+jobs:
+  pytests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.6, 3.7, 3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        pip install --upgrade pip
+        pip install .
+        pip install pytest
+        pip install -r requirements.txt
+    - name: Run unit tests
+      run: |
+        pytest -v
diff --git a/.github/workflows/macos-tests.yml b/.github/workflows/macos-tests.yml
new file mode 100644
index 0000000..e6851d0
--- /dev/null
+++ b/.github/workflows/macos-tests.yml
@@ -0,0 +1,28 @@
+name: macOS
+
+on: [push, pull_request]
+
+jobs:
+  pytests:
+    runs-on: macOS-latest
+    strategy:
+      matrix:
+        python-version: [3.6, 3.7, 3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        pip install --upgrade pip
+        pip install .
+        pip install pytest
+        pip install -r requirements.txt
+    - name: Run unit tests
+      run: |
+        mkdir ~/testfolder
+        sudo chmod -R u-rwx ~/testfolder
+        pytest -v
diff --git a/.github/workflows/windows-tests.yml b/.github/workflows/windows-tests.yml
new file mode 100644
index 0000000..28419c0
--- /dev/null
+++ b/.github/workflows/windows-tests.yml
@@ -0,0 +1,26 @@
+name: Windows
+
+on: [push, pull_request]
+
+jobs:
+  pytest:
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        python-version: [3.6, 3.7, 3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        pip install --upgrade pip
+        pip install .
+        pip install pytest
+        pip install -r requirements.txt
+    - name: Run unit tests
+      run: |
+        pytest -v
diff --git a/README.md b/README.md
index de90966..44ed843 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,3 @@
 # livelog
 
-Work in progress
+[![Linux](https://github.com/PabloLec/livelog/actions/workflows/linux-tests.yml/badge.svg)](https://github.com/PabloLec/livelog/actions/workflows/linux-tests.yml)[![macOS](https://github.com/PabloLec/livelog/actions/workflows/macos-tests.yml/badge.svg)](https://github.com/PabloLec/livelog/actions/workflows/macos-tests.yml)[![Windows](https://github.com/PabloLec/livelog/actions/workflows/windows-tests.yml/badge.svg)](https://github.com/PabloLec/livelog/actions/workflows/windows-tests.yml)
diff --git a/livelog/__main__.py b/livelog/__main__.py
index 0f2792a..6bf10b9 100644
--- a/livelog/__main__.py
+++ b/livelog/__main__.py
@@ -41,11 +41,11 @@ def _parse_args():
     args = parser.parse_args()
 
     if args.file is not None:
-        file = Path(args.file)
+        file = Path(args.file).resolve()
     else:
         file = (
             Path("/tmp/livelog.log")
-            if system() == "Darwin"
+            if "darwin" in system().lower()
             else Path(gettempdir()) / "livelog.log"
         )
 
diff --git a/livelog/logger.py b/livelog/logger.py
index e24594a..c15370e 100644
--- a/livelog/logger.py
+++ b/livelog/logger.py
@@ -55,7 +55,7 @@ def __init__(
         if file is None:
             self._file = Path(
                 "/tmp/livelog.log"
-                if system() == "Darwin"
+                if "darwin" in system().lower()
                 else Path(gettempdir()) / "livelog.log"
             )
         else:
@@ -95,10 +95,13 @@ def _verify_file(self):
         """
 
         dir = self._file.parent.resolve()
-        if self._file.is_dir():
-            raise LogFileIsADirectory(path=self._file)
-        if not dir.is_dir():
-            raise LogPathDoesNotExist(path=dir)
+        try:
+            if self._file.is_dir():
+                raise LogFileIsADirectory(path=self._file)
+            if not dir.is_dir():
+                raise LogPathDoesNotExist(path=dir)
+        except PermissionError:
+            raise LogPathInsufficientPermissions(path=dir)
         if not access(dir, X_OK):
             raise LogPathInsufficientPermissions(path=dir)
         self._clear_file()
diff --git a/livelog/reader.py b/livelog/reader.py
index 1b38e34..e105b9a 100644
--- a/livelog/reader.py
+++ b/livelog/reader.py
@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 
-from os import system, access, name, R_OK
+from os import getenv, system, access, R_OK
+from sys import exit as _exit
+from platform import system as system_
 from time import sleep
 from watchdog.observers import Observer
 from watchdog.events import FileSystemEventHandler
@@ -29,7 +31,12 @@ class Reader(FileSystemEventHandler):
             write to output path
     """
 
-    CLEAR_CMD = "cls" if name == "nt" else "clear"
+    if getenv("LIVELOG_ENV") == "TEST":
+        CLEAR_CMD = ""
+    elif "windows" in system_().lower():
+        CLEAR_CMD = "cls"
+    else:
+        CLEAR_CMD = "clear"
     LEVEL_COLORS = {
         "ERR!": Fore.RED,
         "WARN": Fore.YELLOW,
@@ -38,7 +45,7 @@ class Reader(FileSystemEventHandler):
     }
     LONG_LEVEL_TO_SHORT = {
         "ERROR": "ERR!",
-        "WARN": "WARNING",
+        "WARNING": "WARN",
         "INFO": "INFO",
         "DEBUG": "DBUG",
     }
@@ -69,6 +76,9 @@ def __init__(self, file: str, level: str, nocolors: bool):
         self.read_index = 0
 
         system(self.CLEAR_CMD)
+        if not self.file_exists() and getenv("LIVELOG_ENV") == "TEST":
+            print("FILE NOT FOUND:", self.file)
+            _exit()
         while not self.file_exists():
             print("File not found, waiting for creation.")
             sleep(1)
@@ -80,10 +90,13 @@ def verify_file(self):
         """Verify if provided file path is a valid log file."""
 
         dir = self.file.parent.resolve()
-        if self.file.is_dir():
-            raise LogFileIsADirectory(path=self.file)
-        if not dir.is_dir():
-            raise LogPathDoesNotExist(path=dir)
+        try:
+            if self.file.is_dir():
+                raise LogFileIsADirectory(path=self.file)
+            if not dir.is_dir():
+                raise LogPathDoesNotExist(path=dir)
+        except PermissionError:
+            raise LogPathInsufficientPermissions(path=dir)
         if not access(dir, R_OK):
             raise LogPathInsufficientPermissions(path=dir)
 
@@ -148,10 +161,14 @@ def filter_log_level(self, lines: list):
             list: Filtered lines
         """
 
-        for i, line in enumerate(lines):
-            level = line[:4]
+        i = 0
+        for _ in range(len(lines)):
+            level = lines[i][:4]
             if self.LEVELS[self.level] > self.LEVELS[level]:
                 del lines[i]
+                continue
+            i += 1
+
         return lines
 
     def color_line(self, line: str):
@@ -180,6 +197,10 @@ def on_modified(self, *args, **kwargs):
     def loop_without_event(self):
         """If inotify instance limit reached, loop without watching file."""
 
+        if getenv("LIVELOG_ENV") == "TEST":
+            self.print_output()
+            _exit()
+
         while True:
             self.print_output()
             sleep(1)
@@ -199,7 +220,11 @@ def start_reader(file: str, level: str, nocolors: bool):
     observer.schedule(event_handler, file, recursive=True)
     try:
         observer.start()
-        input("")
+        if getenv("LIVELOG_ENV") == "TEST":
+            sleep(2)
+            _exit()
+        else:
+            input("")
         observer.stop()
         observer.join()
     except OSError:
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..7543266
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1,3 @@
+from os import environ
+
+environ["LIVELOG_ENV"] = "TEST"
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..c88b9cd
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,41 @@
+import pytest
+from os import getenv
+from pathlib import Path
+from livelog import Logger
+from platform import system
+
+
+@pytest.fixture(scope="session")
+def restricted_dir():
+    if "darwin" in system().lower():
+        return getenv("HOME") + "/testfolder/"
+    else:
+        return "/root/"
+
+
+@pytest.fixture(scope="session")
+def system_is_windows():
+    return "windows" in system().lower()
+
+
+@pytest.fixture(scope="session")
+def log_file(tmpdir_factory):
+    return tmpdir_factory.mktemp("tmp").join("test.log")
+
+
+@pytest.fixture(scope="function")
+def default_log_file():
+    logger = Logger()
+    logger.debug("It works!")
+
+
+@pytest.fixture(scope="function")
+def reader_test_file(tmpdir_factory):
+    log_file = tmpdir_factory.mktemp("tmp").join("test.log")
+    logger = Logger(file=log_file)
+    logger.debug("debug")
+    logger.info("info")
+    logger.warn("warning")
+    logger.error("error")
+
+    return Path(log_file)
diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..5a687de
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,39 @@
+from subprocess import Popen, PIPE
+
+
+def test_default(default_log_file):
+    print("python3 -m livelog".split())
+    process = Popen("python3 -m livelog".split(), stdout=PIPE)
+    out, _ = process.communicate()
+    assert "It works" in str(out)
+
+
+def test_custom_file(reader_test_file):
+    process = Popen(
+        f"python3 -m livelog -f {reader_test_file}".split(),
+        stdout=PIPE,
+    )
+    out, _ = process.communicate()
+    assert "debug" in str(out)
+
+
+def test_nocolors(reader_test_file):
+    process = Popen(
+        f"python3 -m livelog -f {reader_test_file} --nocolors".split(),
+        stdout=PIPE,
+    )
+    out, _ = process.communicate()
+    assert "DBUG" in str(out)
+    assert "INFO" in str(out)
+    assert "WARN" in str(out)
+    assert "ERR!" in str(out)
+
+
+def test_custom_level(reader_test_file):
+    process = Popen(
+        f"python3 -m livelog -f {reader_test_file} --level=INFO --nocolors".split(),
+        stdout=PIPE,
+    )
+    out, _ = process.communicate()
+    assert "INFO" in str(out)
+    assert "DBUG" not in str(out)
diff --git a/tests/test_logger.py b/tests/test_logger.py
new file mode 100644
index 0000000..b709c19
--- /dev/null
+++ b/tests/test_logger.py
@@ -0,0 +1,236 @@
+from pytest import raises
+from pathlib import Path
+from re import findall
+from livelog import Logger, LoggerSingleton, errors
+
+
+def test_default(log_file):
+    logger = Logger(file=log_file)
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_without_erasing(log_file):
+    logger = Logger(file=log_file, erase=False)
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 2
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 2
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 2
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 2
+    )
+
+
+def test_with_erasing(log_file):
+    logger = Logger(file=log_file)
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_level_info(log_file):
+    logger = Logger(file=log_file, level="INFO")
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_level_warning(log_file):
+    logger = Logger(file=log_file, level="WARNING")
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_level_error(log_file):
+    logger = Logger(file=log_file, level="ERROR")
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_level_custom_case(log_file):
+    logger = Logger(file=log_file, level="iNfO")
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_disabled(log_file):
+    logger = Logger(file=log_file, enabled=False)
+    logger.debug("0")
+    logger.info("1")
+    logger.warn("2")
+    logger.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 0
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 0
+    )
+
+
+def test_singleton(log_file):
+    logger1 = LoggerSingleton(file=log_file)
+    logger1.debug("0")
+    logger1.info("1")
+    logger2 = LoggerSingleton()
+    logger2.warn("2")
+    logger2.error("3")
+    with open(log_file, "r") as f:
+        logs = f.read()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 0)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 1)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 2)", logs)) == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - 3)", logs)) == 1
+    )
+
+
+def test_log_file_is_directory(log_file):
+    dir = Path(log_file).parent
+    with raises(errors.LogFileIsADirectory):
+        Logger(file=dir)
+
+
+def test_wrong_log_path():
+    with raises(errors.LogPathDoesNotExist):
+        Logger(file="/foo/bar/test.log")
+
+
+def test_insufficient_permissions(restricted_dir, system_is_windows):
+    if system_is_windows:
+        return
+
+    with raises(errors.LogPathInsufficientPermissions):
+        Logger(file=restricted_dir + "test.log")
+
+
+def test_unknow_log_level(log_file):
+    with raises(errors.LogLevelDoesNotExist):
+        Logger(file=log_file, level="TEST")
diff --git a/tests/test_reader.py b/tests/test_reader.py
new file mode 100644
index 0000000..da17a58
--- /dev/null
+++ b/tests/test_reader.py
@@ -0,0 +1,159 @@
+from re import findall
+from pytest import raises
+from pathlib import Path
+from colorama import Style, Fore
+from livelog.reader import Reader
+from livelog import errors
+
+
+def escape(string):
+    return string.replace("\\", "\\\\")
+
+
+DIM = escape(Style.DIM)
+BRIGHT = escape(Style.BRIGHT)
+NORMAL = escape(Style.NORMAL)
+WHITE = escape(Fore.WHITE)
+BLUE = escape(Fore.BLUE)
+YELLOW = escape(Fore.YELLOW)
+RED = escape(Fore.RED)
+RESET_ALL = escape(Style.RESET_ALL)
+
+
+def test_reader_default(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="DEBUG",
+        nocolors=False,
+    )
+    out, _ = capfd.readouterr()
+
+    debug_line = findall(r"(^.* - .*debug.*\n)", out)[0]
+    info_line = findall(r"(\n.* - .*info.*\n)", out)[0]
+    warning_line = findall(r"(\n.* - .*warning.*\n)", out)[0]
+    error_line = findall(r"(\n.* - .*error.*\n)", out)[0]
+
+    assert all(x in debug_line for x in (DIM, BRIGHT, NORMAL, WHITE, RESET_ALL))
+    assert all(x in info_line for x in (DIM, BRIGHT, NORMAL, BLUE, RESET_ALL))
+    assert all(x in warning_line for x in (DIM, BRIGHT, NORMAL, YELLOW, RESET_ALL))
+    assert all(x in error_line for x in (DIM, BRIGHT, NORMAL, RED, RESET_ALL))
+
+
+def test_reader_level_info(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="INFO",
+        nocolors=False,
+    )
+    out, _ = capfd.readouterr()
+
+    assert len(findall(r"(.* - .*debug.*\n)", out)) == 0
+    assert len(findall(r"(^.* - .*info.*\n)", out)) == 1
+    assert len(findall(r"(\n.* - .*warning.*\n)", out)) == 1
+    assert len(findall(r"(\n.* - .*error.*\n)", out)) == 1
+
+
+def test_reader_level_warning(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="WARNING",
+        nocolors=False,
+    )
+    out, _ = capfd.readouterr()
+
+    print(out)
+
+    assert len(findall(r"(.* - .*debug.*\n)", out)) == 0
+    assert len(findall(r"(.* - .*info.*\n)", out)) == 0
+    assert len(findall(r"^(.* - .*warning.*\n)", out)) == 1
+    assert len(findall(r"(\n.* - .*error.*\n)", out)) == 1
+
+
+def test_reader_level_error(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="ERROR",
+        nocolors=False,
+    )
+    out, _ = capfd.readouterr()
+
+    print(out)
+
+    assert len(findall(r"(.* - .*debug.*\n)", out)) == 0
+    assert len(findall(r"(.* - .*info.*\n)", out)) == 0
+    assert len(findall(r"(.* - .*warning.*\n)", out)) == 0
+    assert len(findall(r"(^.* - .*error.*\n)", out)) == 1
+
+
+def test_reader_nocolors(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="DEBUG",
+        nocolors=True,
+    )
+    out, _ = capfd.readouterr()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - debug)", out))
+        == 1
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - info)", out)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - warning)", out))
+        == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - error)", out))
+        == 1
+    )
+
+
+def test_reader_level_custom_case(reader_test_file, capfd):
+    Reader(
+        file=reader_test_file,
+        level="iNfO",
+        nocolors=True,
+    )
+    out, _ = capfd.readouterr()
+
+    assert (
+        len(findall(r"(DBUG \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - debug)", out))
+        == 0
+    )
+    assert (
+        len(findall(r"(INFO \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - info)", out)) == 1
+    )
+    assert (
+        len(findall(r"(WARN \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - warning)", out))
+        == 1
+    )
+    assert (
+        len(findall(r"(ERR! \\| [0-9]{2}:[0-9]{2}:[0-9]{2}.[0-9]{3} - error)", out))
+        == 1
+    )
+
+
+def test_reader_log_file_is_directory(reader_test_file):
+    dir = Path(reader_test_file).parent
+    with raises(errors.LogFileIsADirectory):
+        Reader(file=dir, level="DEBUG", nocolors=True)
+
+
+def test_reader_wrong_log_path():
+    with raises(errors.LogPathDoesNotExist):
+        Reader(file=Path("/foo/bar/test.log"), level="DEBUG", nocolors=True)
+
+
+def test_reader_insufficient_permissions(restricted_dir, system_is_windows):
+    if system_is_windows:
+        return
+
+    with raises(errors.LogPathInsufficientPermissions):
+        Reader(file=Path(restricted_dir + "test.log"), level="DEBUG", nocolors=True)
+
+
+def test_reader_unknow_log_level(reader_test_file):
+    with raises(errors.LogLevelDoesNotExist):
+        Reader(file=reader_test_file, level="TEST", nocolors=True)