diff --git a/tests/class_spec.lua b/tests/class_spec.lua
new file mode 100644
index 00000000..ef2f1657
--- /dev/null
+++ b/tests/class_spec.lua
@@ -0,0 +1,33 @@
+local class = require('CopilotChat.utils.class')
+
+describe('CopilotChat.utils.class', function()
+  it('creates a simple class', function()
+    local Foo = class(function(self, x)
+      self.x = x
+    end)
+    local obj = Foo(42)
+    assert.equals(42, obj.x)
+  end)
+
+  it('supports init method', function()
+    local Bar = class(function(self, y)
+      self.y = y
+    end)
+    local obj = Bar.new(7)
+    assert.equals(7, obj.y)
+    obj:init(8)
+    assert.equals(8, obj.y)
+  end)
+
+  it('supports inheritance', function()
+    local Parent = class(function(self)
+      self.val = 1
+    end)
+    local Child = class(function(self)
+      self.val = 2
+    end, Parent)
+    local obj = Child()
+    assert.equals(2, obj.val)
+    assert.equals(Parent, getmetatable(Child).__index)
+  end)
+end)
diff --git a/tests/orderedmap_spec.lua b/tests/orderedmap_spec.lua
new file mode 100644
index 00000000..9000915c
--- /dev/null
+++ b/tests/orderedmap_spec.lua
@@ -0,0 +1,28 @@
+local orderedmap = require('CopilotChat.utils.orderedmap')
+
+describe('CopilotChat.utils.orderedmap', function()
+  it('sets and gets values', function()
+    local map = orderedmap()
+    map:set('a', 1)
+    map:set('b', 2)
+    assert.equals(1, map:get('a'))
+    assert.equals(2, map:get('b'))
+  end)
+
+  it('preserves insertion order', function()
+    local map = orderedmap()
+    map:set('x', 10)
+    map:set('y', 20)
+    map:set('z', 30)
+    assert.are.same({ 'x', 'y', 'z' }, map:keys())
+    assert.are.same({ 10, 20, 30 }, map:values())
+  end)
+
+  it('overwrites value but not order', function()
+    local map = orderedmap()
+    map:set('a', 1)
+    map:set('a', 2)
+    assert.are.same({ 'a' }, map:keys())
+    assert.are.same({ 2 }, map:values())
+  end)
+end)
diff --git a/tests/stringbuffer_spec.lua b/tests/stringbuffer_spec.lua
new file mode 100644
index 00000000..d491fd43
--- /dev/null
+++ b/tests/stringbuffer_spec.lua
@@ -0,0 +1,23 @@
+local stringbuffer = require('CopilotChat.utils.stringbuffer')
+
+describe('CopilotChat.utils.stringbuffer', function()
+  it('concatenates strings with put', function()
+    local buf = stringbuffer()
+    buf:put('hello')
+    buf:put(' ')
+    buf:put('world')
+    assert.equals('hello world', buf:tostring())
+  end)
+
+  it('sets buffer with set', function()
+    local buf = stringbuffer()
+    buf:put('foo')
+    buf:set('bar')
+    assert.equals('bar', buf:tostring())
+  end)
+
+  it('handles empty buffer', function()
+    local buf = stringbuffer()
+    assert.equals('', buf:tostring())
+  end)
+end)