diff --git a/tests/test_utils.lua b/tests/test_utils.lua
new file mode 100644
index 0000000..e934dbb
--- /dev/null
+++ b/tests/test_utils.lua
@@ -0,0 +1,198 @@
+local lu = require"luaunit.luaunit"
+local utils = require"lua.jsonfly.utils"
+
+function testBasicKey()
+    local key = "foo.bar"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "bar",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+function testArrayKey()
+    local key = "foo.0.bar"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        },
+        {
+            type = "array_wrapper",
+        },
+        {
+            type = "array_index",
+            key = 0,
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "bar",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+function testNestedArrayKey()
+    local key = "foo.0.bar.1.baz"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        },
+        {
+            type = "array_wrapper",
+        },
+        {
+            type = "array_index",
+            key = 0,
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "bar",
+        },
+        {
+            type = "array_wrapper",
+        },
+        {
+            type = "array_index",
+            key = 1,
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "baz",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+function testEscapedArrayDoesNotCreateArray()
+    local key = "foo.\\0.bar"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "0",
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "bar",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+function testBracketArrayKey()
+    local key = "foo.[0].bar"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        },
+        {
+            type = "array_wrapper",
+        },
+        {
+            type = "array_index",
+            key = 0,
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "bar",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+function testRootArrayKey()
+    local key = "0.foo"
+    ---@type KeyDescription[]
+    local EXPECTED = {
+        {
+            type = "array_wrapper",
+        },
+        {
+            type = "array_index",
+            key = 0,
+        },
+        {
+            type = "object_wrapper",
+        },
+        {
+            type = "key",
+            key = "foo",
+        }
+    }
+
+    local descriptor = utils:extract_key_description(key)
+
+    lu.assertEquals(descriptor, EXPECTED)
+end
+
+
+os.exit( lu.LuaUnit.run() )
+
diff --git a/tests/tests.lua b/tests/tests.lua
deleted file mode 100644
index fb7f278..0000000
--- a/tests/tests.lua
+++ /dev/null
@@ -1,5 +0,0 @@
-local lu = require"luaunit.luaunit"
-
-
-os.exit( lu.LuaUnit.run() )
-