diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..5d0200a
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,27 @@
+name: CI Testing
+
+on:
+  push:
+    pull_request:
+
+    workflow_dispatch:
+
+jobs:
+  testing:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+
+      - name: Install deps
+        run: |
+          pip3 --version
+          pip3 install .[dev]
+
+      - name: Run tests
+        run: pytest
+
+  code_style_checking:
+    uses: ./.github/workflows/styling.yml
\ No newline at end of file
diff --git a/.github/workflows/styling.yml b/.github/workflows/styling.yml
index aa2042b..dbf449c 100644
--- a/.github/workflows/styling.yml
+++ b/.github/workflows/styling.yml
@@ -10,6 +10,7 @@ on:
     paths:
       - "**.py"
   workflow_dispatch:
+  workflow_call:
 
 jobs:
   code_style_checking:
diff --git a/regexfactory/__init__.py b/regexfactory/__init__.py
index e3d2b8a..06b92b3 100644
--- a/regexfactory/__init__.py
+++ b/regexfactory/__init__.py
@@ -23,7 +23,7 @@
     WHITESPACE,
     WORD,
 )
-from .pattern import RegexPattern, escape, join
+from .pattern import ESCAPED_CHARACTERS, RegexPattern, ValidPatternType, escape, join
 from .patterns import (
     Amount,
     Comment,
diff --git a/setup.cfg b/setup.cfg
index 69fe130..c2e4b6b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -21,6 +21,23 @@ classifiers =
 zip_safe = True
 packages = regexfactory
 
+[options.extras_require]
+dev =
+    isort
+    black
+    flake8
+    pylint
+    pytest
+    hypothesis
+
+[tool:pytest]
+markers =
+    patterns: Tests for classes in regexfactory/patterns.py
+    pattern: Tests for classes in regexfactory/pattern.py
+addopts = -ra --hypothesis-show-statistics --hypothesis-profile=default
+testpaths =
+    tests
+
 [flake8]
 ignore = E501
 exclude = .git, __pycache__, .github
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..e5c6d22
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,4 @@
+from hypothesis import settings
+
+# Set default profile to use 500 examples
+settings.register_profile("default", max_examples=500)
diff --git a/tests/strategies.py b/tests/strategies.py
new file mode 100644
index 0000000..74d52c6
--- /dev/null
+++ b/tests/strategies.py
@@ -0,0 +1,22 @@
+from hypothesis import strategies as st
+
+from regexfactory.pattern import ESCAPED_CHARACTERS
+
+# Strategy to generate characters that are not used in escapes
+non_escape_char = st.characters(blacklist_characters=list(ESCAPED_CHARACTERS))
+
+
+# Strategy to generate text that avoids escaped characters
+non_escaped_text = st.text(min_size=1, alphabet=non_escape_char)
+
+
+# Strategy to produce either None or a positive integer
+optional_step = st.one_of(st.none(), st.integers(min_value=1))
+
+
+def build_bounds(lower_bound, step) -> range:
+    """
+    Function to generate a tuple of (lower, upper) in which lower < upper
+    """
+    upper_bound = lower_bound + step
+    return range(lower_bound, upper_bound + 1)
diff --git a/tests/test_amount.py b/tests/test_amount.py
new file mode 100644
index 0000000..7d96735
--- /dev/null
+++ b/tests/test_amount.py
@@ -0,0 +1,89 @@
+from typing import Optional
+
+import pytest
+from hypothesis import given
+from hypothesis import strategies as st
+from strategies import build_bounds, optional_step
+
+from regexfactory import Amount, ValidPatternType
+
+
+def build_amount(
+    pattern: ValidPatternType,
+    start: int,
+    or_more: bool,
+    greedy: bool,
+    step: Optional[int],
+):
+    """
+    General Amount builder. Note that the `j` parameter is constructed as
+        the step plus start when step is defined. When step is None we assume
+        that no upper bound is present.
+    """
+    stop_value = None
+    if step is not None:
+        stop_value = start + step
+    return Amount(
+        pattern=pattern, i=start, j=stop_value, or_more=or_more, greedy=greedy
+    )
+
+
+@pytest.mark.patterns
+@given(st.text(min_size=1), st.integers(min_value=1))
+def test_amount_single_count(word, count):
+    """
+    Test to ensure that when `or_more=False` and no upper bound is
+        provided the regex will be of the form word{count}.
+    """
+    actual = Amount(word, i=count, or_more=False)
+    assert actual.regex == "{word}{{{count}}}".format(word=word, count=str(count))
+
+
+@pytest.mark.patterns
+@given(
+    st.text(min_size=1),
+    st.builds(
+        build_bounds,
+        lower_bound=st.integers(min_value=1),
+        step=st.integers(min_value=1),
+    ),
+)
+def test_amount_lower_upper(word, bound: range):
+    """
+    Test to ensure that if a lower and upper bound are provided then the
+        regex of the resulting `Amount` will be of the form {word}{lower,upper}.
+    """
+    actual = Amount(word, bound.start, bound.stop)
+    expected = "{word}{{{lower},{upper}}}".format(
+        word=word, lower=str(bound.start), upper=str(bound.stop)
+    )
+    assert actual.regex == expected
+
+
+@pytest.mark.patterns
+@given(st.text(min_size=1), st.integers(min_value=1))
+def test_amount_or_more(word, count):
+    """
+    Test to ensure that when `or_more=True` and no upper bound is
+        provided the regex will be of the form word{count,}.
+    """
+    actual = Amount(word, count, or_more=True)
+    assert actual.regex == "{word}{{{count},}}".format(word=word, count=str(count))
+
+
+@pytest.mark.patterns
+@given(
+    st.builds(
+        build_amount,
+        pattern=st.text(min_size=1),
+        start=st.integers(min_value=1),
+        or_more=st.booleans(),
+        greedy=st.just(False),
+        step=optional_step,
+    )
+)
+def test_amount_non_greedy(amt):
+    """
+    Test to ensure that instances of Amount with greedy as False will end with "?"
+    """
+    assert amt.regex.endswith("?")
diff --git a/tests/test_join.py b/tests/test_join.py
new file mode 100644
index 0000000..727cdf6
--- /dev/null
+++ b/tests/test_join.py
@@ -0,0 +1,18 @@
+import pytest
+from hypothesis import example, given
+from hypothesis import strategies as st
+from strategies import non_escaped_text
+
+from regexfactory.pattern import join
+
+
+@pytest.mark.pattern
+@given(st.lists(elements=non_escaped_text, min_size=1, max_size=10, unique=True))
+@example(words=["0", "1"])
+def test_join(words: list):
+    """
+    Tests to capture that the join function concatenates the expressions and
+        each word in the list is found in the larger regex.
+    """
+    joined_regex = join(*words)
+    assert joined_regex.regex == "".join(words)
diff --git a/tests/test_or.py b/tests/test_or.py
new file mode 100644
index 0000000..b1b6579
--- /dev/null
+++ b/tests/test_or.py
@@ -0,0 +1,26 @@
+import re
+
+import pytest
+from hypothesis import example, given
+from hypothesis import strategies as st
+from strategies import non_escaped_text
+
+from regexfactory import Or
+
+
+@pytest.mark.patterns
+@given(
+    st.lists(
+        non_escaped_text,
+        min_size=1,
+        max_size=10,
+    )
+)
+@example(arr=["0", "0"])
+def test_matching_or(arr: list):
+    actual = Or(*arr)
+    if len(arr) == 1:
+        assert isinstance(actual.match(arr[0]), re.Match)
+    else:
+        for value in arr:
+            assert isinstance(actual.match(value), re.Match)
diff --git a/tests/test_range.py b/tests/test_range.py
new file mode 100644
index 0000000..b969b61
--- /dev/null
+++ b/tests/test_range.py
@@ -0,0 +1,25 @@
+import pytest
+
+from regexfactory import Range
+
+
+@pytest.mark.patterns
+def test_numeric_range():
+    start = "0"
+    end = "9"
+    assert Range(start, end).regex == "[0-9]"
+
+
+@pytest.mark.patterns
+@pytest.mark.parametrize(
+    "start, stop, expected",
+    [
+        ("0", "9", "[0-9]"),
+        ("a", "f", "[a-f]"),
+        ("r", "q", "[r-q]"),
+        ("A", "Z", "[A-Z]"),
+    ],
+)
+def test_range_parameters(start, stop, expected):
+    actual = Range(start=start, stop=stop)
+    assert actual.regex == expected
diff --git a/tests/test_set.py b/tests/test_set.py
new file mode 100644
index 0000000..d400c8e
--- /dev/null
+++ b/tests/test_set.py
@@ -0,0 +1,16 @@
+import re
+
+import pytest
+from hypothesis import given
+from hypothesis import strategies as st
+from strategies import non_escape_char
+
+from regexfactory import Set
+
+
+@pytest.mark.patterns
+@given(st.lists(elements=non_escape_char, min_size=1))
+def test_set(chars: list):
+    actual = Set(*chars)
+    for value in chars:
+        assert isinstance(actual.match(value), re.Match)