[Test] Add integration test: LGraph snapshot (#591)

- Runs basic Litegraph init before performing the snapshot
- Allows a significantly more useful verification of the public API

test/ConfigureGraph.test.ts

@@ -0,0 +1,15 @@
+import { describe } from "vitest"
+import { LGraph } from "@/litegraph"
+import { dirtyTest } from "./testExtensions"
+
+describe("LGraph configure()", () => {
+  dirtyTest("LGraph matches previous snapshot (normal configure() usage)", ({ expect, minimalSerialisableGraph, basicSerialisableGraph }) => {
+    const configuredMinGraph = new LGraph()
+    configuredMinGraph.configure(minimalSerialisableGraph)
+    expect(configuredMinGraph).toMatchSnapshot("configuredMinGraph")
+
+    const configuredBasicGraph = new LGraph()
+    configuredBasicGraph.configure(basicSerialisableGraph)
+    expect(configuredBasicGraph).toMatchSnapshot("configuredBasicGraph")
+  })
+})