test: add unit tests for class, orderedmap, stringbuffer (#1372)

* test: add unit tests for class, orderedmap, stringbuffer

Add new unit tests for CopilotChat.utils.class, orderedmap, and stringbuffer
modules. These tests cover class creation, inheritance, ordered map behavior,
and string buffer operations to improve code reliability and coverage.

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: deathbeam

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)

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)

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)