diff --git a/tests/roblox/instance/methods/Destroy.luau b/tests/roblox/instance/methods/Destroy.luau
new file mode 100644
index 0000000..113fead
--- /dev/null
+++ b/tests/roblox/instance/methods/Destroy.luau
@@ -0,0 +1,35 @@
+local roblox = require("@lune/roblox") :: any
+local Instance = roblox.Instance
+
+local root = Instance.new("Folder")
+local child = Instance.new("Model")
+local descendant = Instance.new("Part")
+
+child.Parent = root
+descendant.Parent = child
+
+root:Destroy()
+
+assert(not pcall(function()
+	return root.Name
+end))
+
+assert(not pcall(function()
+	return root.Parent
+end))
+
+assert(not pcall(function()
+	return child.Name
+end))
+
+assert(not pcall(function()
+	return child.Parent
+end))
+
+assert(not pcall(function()
+	return descendant.Name
+end))
+
+assert(not pcall(function()
+	return descendant.Parent
+end))
diff --git a/tests/roblox/instance/methods/IsA.luau b/tests/roblox/instance/methods/IsA.luau
new file mode 100644
index 0000000..1732af4
--- /dev/null
+++ b/tests/roblox/instance/methods/IsA.luau
@@ -0,0 +1,27 @@
+local roblox = require("@lune/roblox") :: any
+local Instance = roblox.Instance
+
+local part = Instance.new("Part")
+local workspace = Instance.new("Workspace")
+
+-- Valid
+
+assert(part:IsA("Part") == true)
+assert(part:IsA("BasePart") == true)
+assert(part:IsA("PVInstance") == true)
+assert(part:IsA("Instance") == true)
+
+assert(workspace:IsA("Workspace") == true)
+assert(workspace:IsA("Model") == true)
+assert(workspace:IsA("Instance") == true)
+
+-- Invalid
+
+assert(part:IsA("part") == false)
+assert(part:IsA("Base-Part") == false)
+assert(part:IsA("Model") == false)
+assert(part:IsA("Paart") == false)
+
+assert(workspace:IsA("Service") == false)
+assert(workspace:IsA(".") == false)
+assert(workspace:IsA("") == false)
diff --git a/tests/roblox/instance/methods/IsAncestorOf.luau b/tests/roblox/instance/methods/IsAncestorOf.luau
new file mode 100644
index 0000000..a482c97
--- /dev/null
+++ b/tests/roblox/instance/methods/IsAncestorOf.luau
@@ -0,0 +1,21 @@
+local roblox = require("@lune/roblox") :: any
+local Instance = roblox.Instance
+
+local root = Instance.new("Folder")
+local child = Instance.new("Model")
+local descendant = Instance.new("Part")
+
+child.Parent = root
+descendant.Parent = child
+
+assert(not root:IsAncestorOf(root))
+assert(not child:IsAncestorOf(root))
+assert(not descendant:IsAncestorOf(root))
+
+assert(root:IsAncestorOf(child))
+assert(not child:IsAncestorOf(child))
+assert(not descendant:IsAncestorOf(child))
+
+assert(root:IsAncestorOf(descendant))
+assert(child:IsAncestorOf(descendant))
+assert(not descendant:IsAncestorOf(descendant))
diff --git a/tests/roblox/instance/methods/IsDescendantOf.luau b/tests/roblox/instance/methods/IsDescendantOf.luau
new file mode 100644
index 0000000..8a65c64
--- /dev/null
+++ b/tests/roblox/instance/methods/IsDescendantOf.luau
@@ -0,0 +1,21 @@
+local roblox = require("@lune/roblox") :: any
+local Instance = roblox.Instance
+
+local root = Instance.new("Folder")
+local child = Instance.new("Model")
+local descendant = Instance.new("Part")
+
+child.Parent = root
+descendant.Parent = child
+
+assert(not root:IsDescendantOf(root))
+assert(child:IsDescendantOf(root))
+assert(descendant:IsDescendantOf(root))
+
+assert(not root:IsDescendantOf(child))
+assert(not child:IsDescendantOf(child))
+assert(descendant:IsDescendantOf(child))
+
+assert(not root:IsDescendantOf(descendant))
+assert(not child:IsDescendantOf(descendant))
+assert(not descendant:IsDescendantOf(descendant))