diff --git a/tests/test_replybuilder.py b/tests/test_replybuilder.py
new file mode 100644
index 0000000..9266e75
--- /dev/null
+++ b/tests/test_replybuilder.py
@@ -0,0 +1,105 @@
+from datetime import timedelta
+from django.test import TestCase
+from board.models import Board, Post
+from board.templatetags.post_body import ReplyBuilder
+
+
+class ReplyBuilderTestCase(TestCase):
+    def setUp(self):
+        Board.objects.create(
+            url="test", name="test", post_cooldown=timedelta(seconds=0)
+        )
+
+    def test_quote(self):
+        expected = [
+            (
+                "this is some text that shouldn't be quoted.",
+                "this is some text that shouldn't be quoted.",
+            ),
+            (
+                ">implying this quotes text correctly",
+                '<span class="quote">&gt;implying this quotes text correctly</span>',
+            ),
+            (
+                "&gt;implying this &gt;quotes &gt;text correctly",
+                '<span class="quote">&gt;implying this &gt;quotes &gt;text correctly</span>',
+            ),
+            (
+                """
+&gt;implying this quotes text correctly
+nothing ever changes
+""",
+                '<span class="quote">&gt;implying this quotes text correctly</span><br/>nothing ever changes',
+            ),
+            (
+                """
+what happened to the 1 2 3 4 5 6 7 8 9
+&gt;implying this quotes text correctly
+nothing ever changes
+""",
+                'what happened to the 1 2 3 4 5 6 7 8 9<br/><span class="quote">&gt;implying this quotes text correctly</span><br/>nothing ever changes',
+            ),
+            (
+                """
+nothing ever changes
+&gt;implying this quotes text correctly
+what happened to the 1 2 3 4 5 6 7 8 9
+""",
+                'nothing ever changes<br/><span class="quote">&gt;implying this quotes text correctly</span><br/>what happened to the 1 2 3 4 5 6 7 8 9',
+            ),
+        ]
+
+        for input, output in expected:
+            rb = ReplyBuilder(input.strip())
+            self.assertEquals(rb.build(), output)
+
+    def test_reply(self):
+        board = Board.objects.get(url="test")
+        post1 = Post.objects.create(board=board, text="test 1", ip="127.0.0.1")
+        post2 = Post.objects.create(board=board, text="test 1", ip="127.0.0.1")
+        post3 = Post.objects.create(board=board, text="test 1", ip="127.0.0.1")
+
+        expected = [
+            (
+                f"&gt;&gt;{post1.id}",
+                f'<a class="post_link" href="{post1.get_absolute_url()}">&gt;&gt;{post1.id}</a>',
+            ),
+            (
+                f"&gt;&gt;{post2.id}",
+                f'<a class="post_link" href="{post2.get_absolute_url()}">&gt;&gt;{post2.id}</a>',
+            ),
+            (
+                f"&gt;&gt;{post1.id} &gt;&gt;{post2.id} &gt;&gt;{post3.id}",
+                f'<a class="post_link" href="{post1.get_absolute_url()}">&gt;&gt;{post1.id}</a> '
+                f'<a class="post_link" href="{post2.get_absolute_url()}">&gt;&gt;{post2.id}</a> '
+                f'<a class="post_link" href="{post3.get_absolute_url()}">&gt;&gt;{post3.id}</a>',
+            ),
+            (
+                f"&gt;&gt;999999",
+                f'<span class="post_link_broken">&gt;&gt;999999</span>',
+            ),
+        ]
+
+        for input, output in expected:
+            rb = ReplyBuilder(input.strip())
+            self.assertEquals(rb.build(), output)
+
+    def test_spoiler(self):
+        expected = [
+            (
+                "[spoiler]This is a spoiler[/spoiler]",
+                '<span class="spoiler">This is a spoiler</span>',
+            ),
+            (
+                r"\[spoiler]This is an escaped spoiler[/spoiler]",
+                "[spoiler]This is an escaped spoiler[/spoiler]",
+            ),
+            (
+                "[spoiler]This is an unfinished spoiler",
+                '<span class="spoiler">This is an unfinished spoiler</span>',
+            ),
+        ]
+
+        for input, output in expected:
+            rb = ReplyBuilder(input.strip(), parse_spoilers=True)
+            self.assertEquals(rb.build(), output)