diff --git a/pyproject.toml b/pyproject.toml
index 8c6668f..35dda01 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,7 +62,7 @@ addopts = ["--maxfail=2", "-rf"]
 
 [tool.coverage.run]
 branch = true
-omit = ["conftest.py"]
+omit = ["conftest.py", "spiderweb/tests/*"]
 
 [tool.coverage.report]
 # Regexes for lines to exclude from consideration
@@ -81,6 +81,8 @@ exclude_also = [
 
     # Don't complain about abstract methods, they aren't run:
     "@(abc\\.)?abstractmethod",
-    ]
+    # Type checking lines are never run:
+    "if TYPE_CHECKING:",
+]
 
 ignore_errors = true
\ No newline at end of file
diff --git a/spiderweb/main.py b/spiderweb/main.py
index ddc6a37..b5a935c 100644
--- a/spiderweb/main.py
+++ b/spiderweb/main.py
@@ -175,6 +175,8 @@ class SpiderwebRouter(LocalServerMixin, MiddlewareMixin, RoutesMixin, FernetMixi
         )
 
         if self.staticfiles_dirs:
+            if not isinstance(self.staticfiles_dirs, list):
+                self.staticfiles_dirs = [self.staticfiles_dirs]
             for static_dir in self.staticfiles_dirs:
                 static_dir = pathlib.Path(static_dir)
                 if not pathlib.Path(self.BASE_DIR / static_dir).exists():
diff --git a/spiderweb/tests/staticfiles/.gitkeep b/spiderweb/tests/staticfiles/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/spiderweb/tests/staticfiles/file_for_testing_fileresponse.txt b/spiderweb/tests/staticfiles/file_for_testing_fileresponse.txt
new file mode 100644
index 0000000..32f95c0
--- /dev/null
+++ b/spiderweb/tests/staticfiles/file_for_testing_fileresponse.txt
@@ -0,0 +1 @@
+hi
\ No newline at end of file
diff --git a/spiderweb/tests/staticfiles/style.css b/spiderweb/tests/staticfiles/style.css
new file mode 100644
index 0000000..dc462a9
--- /dev/null
+++ b/spiderweb/tests/staticfiles/style.css
@@ -0,0 +1,6 @@
+.body {
+    background-color: #f0f0f0;
+    font-family: Arial, sans-serif;
+    margin: 0;
+    padding: 0;
+}
\ No newline at end of file
diff --git a/spiderweb/tests/test_cookies.py b/spiderweb/tests/test_cookies.py
new file mode 100644
index 0000000..9ecbea2
--- /dev/null
+++ b/spiderweb/tests/test_cookies.py
@@ -0,0 +1,149 @@
+from datetime import datetime
+
+import pytest
+
+from spiderweb import HttpResponse
+from spiderweb.exceptions import GeneralException
+from spiderweb.tests.helpers import setup
+
+
+def test_valid_cookie():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie", "value")
+        return resp
+
+    response = app(environ, start_response)
+    assert response == [b"Hello, World!"]
+    assert start_response.get_headers()["set-cookie"] == "cookie=value"
+
+
+def test_invalid_cookie_name():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie$%^&*name", "value")
+        return resp
+
+    with pytest.raises(GeneralException) as exc:
+        app(environ, start_response)
+
+    assert str(exc.value) == (
+        "GeneralException() - Cookie name has illegal characters."
+        " See https://developer.mozilla.org/en-US/docs/Web/HTTP/"
+        "Headers/Set-Cookie#attributes for information on allowed"
+        " characters."
+    )
+
+
+def test_cookie_with_domain():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie", "value", domain="example.com")
+        return resp
+
+    response = app(environ, start_response)
+    assert response == [b"Hello, World!"]
+    assert (
+        start_response.get_headers()["set-cookie"] == "cookie=value; Domain=example.com"
+    )
+
+
+def test_cookie_with_expires():
+    app, environ, start_response = setup()
+    expiry_time = datetime(2024, 10, 22, 7, 28)
+    expiry_time_str = expiry_time.strftime("%a, %d %b %Y %H:%M:%S GMT")
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie", "value", expires=expiry_time)
+        return resp
+
+    response = app(environ, start_response)
+    assert response == [b"Hello, World!"]
+    assert (
+        start_response.get_headers()["set-cookie"]
+        == f"cookie=value; Expires={expiry_time_str}"
+    )
+
+
+def test_cookie_with_max_age():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie", "value", max_age=3600)
+        return resp
+
+    response = app(environ, start_response)
+    assert response == [b"Hello, World!"]
+    assert start_response.get_headers()["set-cookie"] == "cookie=value; Max-Age=3600"
+
+
+def test_cookie_with_invalid_samesite_attr():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!")
+        resp.set_cookie("cookie", "value", same_site="invalid")
+        return resp
+
+    with pytest.raises(GeneralException) as exc:
+        app(environ, start_response)
+
+    assert str(exc.value) == (
+        "GeneralException() - Invalid value invalid for `same_site` cookie"
+        " attribute. Valid options are 'strict', 'lax', or 'none'."
+    )
+
+
+def test_cookie_partitioned_attr():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse()
+        resp.set_cookie("cookie", "value", partitioned=True)
+        return resp
+
+    app(environ, start_response)
+    assert start_response.get_headers()["set-cookie"] == "cookie=value; Partitioned"
+
+
+def test_cookie_secure_attr():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse()
+        resp.set_cookie("cookie", "value", secure=True)
+        return resp
+
+    app(environ, start_response)
+    assert start_response.get_headers()["set-cookie"] == "cookie=value; Secure"
+
+
+def test_setting_multiple_cookies():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse()
+        resp.set_cookie("cookie1", "value1")
+        resp.set_cookie("cookie2", "value2")
+        return resp
+
+    app(environ, start_response)
+    assert start_response.headers[-1] == ("set-cookie", "cookie2=value2")
+    assert start_response.headers[-2] == ("set-cookie", "cookie1=value1")
diff --git a/spiderweb/tests/test_jinja_extras.py b/spiderweb/tests/test_jinja_extras.py
new file mode 100644
index 0000000..e218c7f
--- /dev/null
+++ b/spiderweb/tests/test_jinja_extras.py
@@ -0,0 +1,35 @@
+from spiderweb.constants import DEFAULT_ENCODING
+from spiderweb.response import TemplateResponse
+from spiderweb.tests.helpers import setup
+
+
+def test_str_template_with_static_tag():
+    # test that the static tag works
+    template = """
+    <html>
+        <head>
+            <title>{{ title }}</title>
+            <link rel="stylesheet" href="{% static 'style.css' %}">
+        </head>
+        <body>
+            <h1>{{ title }}</h1>
+            <p>{{ content }}</p>
+        </body>
+    </html>
+    """
+    context = {"title": "Test", "content": "This is a test."}
+    app, environ, start_response = setup(
+        staticfiles_dirs=["spiderweb/tests/staticfiles"], static_url="blorp"
+    )
+
+    @app.route("/")
+    def index(request):
+        return TemplateResponse(request, template_string=template, context=context)
+
+    rendered_template = (
+        template.replace("{% static 'style.css' %}", "/blorp/style.css")
+        .replace("{{ title }}", "Test")
+        .replace("{{ content }}", "This is a test.")
+    )
+
+    assert app(environ, start_response) == [bytes(rendered_template, DEFAULT_ENCODING)]
diff --git a/spiderweb/tests/test_responses.py b/spiderweb/tests/test_responses.py
index cffa607..768a79b 100644
--- a/spiderweb/tests/test_responses.py
+++ b/spiderweb/tests/test_responses.py
@@ -7,12 +7,14 @@ from spiderweb.exceptions import (
     SpiderwebNetworkException,
     SpiderwebException,
     ReverseNotFound,
+    GeneralException,
 )
 from spiderweb.response import (
     HttpResponse,
     JsonResponse,
     TemplateResponse,
     RedirectResponse,
+    FileResponse,
 )
 from hypothesis import given, strategies as st
 
@@ -240,3 +242,94 @@ def test_reverse_nonexistent_view():
 
     with pytest.raises(ReverseNotFound):
         app.reverse("qwer")
+
+
+def test_setting_content_type_header():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        resp = HttpResponse("Hello, World!", headers={"content-type": "text/html"})
+        return resp
+
+    response = app(environ, start_response)
+    assert response == [b"Hello, World!"]
+    assert start_response.get_headers()["content-type"] == "text/html"
+
+
+def test_httpresponse_str_returns_body():
+    resp = HttpResponse("Hello, World!")
+    assert str(resp) == "Hello, World!"
+
+
+def test_template_response_with_no_templates_raises_errors():
+    app, environ, start_response = setup()
+
+    @app.route("/")
+    def index(request):
+        return TemplateResponse(request, "")
+
+    with pytest.raises(GeneralException) as exc:
+        app(environ, start_response)
+
+    assert (
+        str(exc.value) == "GeneralException() - TemplateResponse requires a template."
+    )
+
+
+def test_template_response_with_no_template_dirs():
+
+    template = TemplateResponse("", "test.html")
+
+    with pytest.raises(GeneralException) as exc:
+        template.render()
+
+    assert str(exc.value) == (
+        "GeneralException() - TemplateResponse has no loader. Did you set templates_dirs?"
+    )
+
+
+def test_file_response():
+    resp = FileResponse("spiderweb/tests/staticfiles/file_for_testing_fileresponse.txt")
+    assert resp.headers["content-type"] == "text/plain"
+    assert resp.render() == [b"hi"]
+
+
+def test_requesting_static_file():
+    app, environ, start_response = setup(
+        staticfiles_dirs=["spiderweb/tests/staticfiles"], debug=True
+    )
+
+    environ["PATH_INFO"] = "/static/file_for_testing_fileresponse.txt"
+
+    assert app(environ, start_response) == [b"hi"]
+
+
+def test_requesting_nonexistent_static_file():
+    app, environ, start_response = setup(
+        staticfiles_dirs=["spiderweb/tests/staticfiles"], debug=True
+    )
+
+    environ["PATH_INFO"] = "/static/does_not_exist.txt"
+
+    assert app(environ, start_response) == [
+        b"Something went wrong.\n\n"
+        b"Code: 404\n\n"
+        b"Msg: Not Found\n\n"
+        b"Desc: The requested resource could not be found"
+    ]
+
+
+def test_static_file_with_unsafe_path():
+    app, environ, start_response = setup(
+        staticfiles_dirs=["spiderweb/tests/staticfiles"], debug=True
+    )
+
+    environ["PATH_INFO"] = "/static/../__init__.py"
+
+    assert app(environ, start_response) == [
+        b"Something went wrong.\n\n"
+        b"Code: 404\n\n"
+        b"Msg: Not Found\n\n"
+        b"Desc: The requested resource could not be found"
+    ]
diff --git a/spiderweb/tests/test_server.py b/spiderweb/tests/test_server.py
new file mode 100644
index 0000000..e950920
--- /dev/null
+++ b/spiderweb/tests/test_server.py
@@ -0,0 +1,15 @@
+import pytest
+
+from spiderweb.exceptions import ConfigError
+from spiderweb.tests.helpers import setup
+
+
+def test_staticfiles_dirs_option():
+    app, environ, start_response = setup(staticfiles_dirs="spiderweb/tests/staticfiles")
+
+    assert app.staticfiles_dirs == ["spiderweb/tests/staticfiles"]
+
+
+def test_staticfiles_dirs_not_found():
+    with pytest.raises(ConfigError):
+        app, environ, start_response = setup(staticfiles_dirs="not/a/real/path")