[www] room converter

apps/www/src/test/room-converter.test.ts

@@ -0,0 +1,102 @@
+import { expect, it } from 'vitest'
+
+import { downgradeRoom, needsDowngrade } from '../room-converter'
+
+// Hand-built protobuf, since no schema exists for a scene: every expectation below is on
+// the wire bytes, which is also all the converter ever looks at.
+function varint(value: bigint): number[] {
+	const out: number[] = []
+	for (;;) {
+		const b = Number(value & 0x7fn)
+		value >>= 7n
+		if (value) {
+			out.push(b | 0x80)
+		} else {
+			out.push(b)
+			return out
+		}
+	}
+}
+const num = (fn: number, value: bigint | number) => [
+	...varint(BigInt(fn << 3)),
+	...varint(BigInt(value)),
+]
+const len = (fn: number, payload: number[]) => [
+	...varint(BigInt((fn << 3) | 2)),
+	...varint(BigInt(payload.length)),
+	...payload,
+]
+const text = (s: string) => [...new TextEncoder().encode(s)]
+const run = (bytes: number[]) => {
+	const { data, stats } = downgradeRoom(Uint8Array.from(bytes))
+	return { bytes: [...data], stats }
+}
+
+const SENTINEL = 0xffff_ffff_ffff_ffffn
+
+it('only a .binpb needs downgrading', () => {
+	expect(needsDowngrade('MyRoom.binpb')).toBe(true)
+	expect(needsDowngrade('MYROOM.BINPB')).toBe(true)
+	expect(needsDowngrade('MyRoom.room')).toBe(false)
+	expect(needsDowngrade('binpb')).toBe(false)
+})
+
+it('applies all four patches', () => {
+	const circuit = len(28, text('Circuit Board'))
+	const { bytes, stats } = run([
+		...num(1, 9),
+		...len(2, [
+			...num(3, 7),
+			...num(100, SENTINEL),
+			...len(14, [...num(1, 4), ...len(5, text('uuid')), ...num(6, 2)]),
+			// A circuit two messages down, and one directly on the object.
+			...len(7, len(8, [...num(1, 1), ...circuit])),
+			...circuit,
+		]),
+		...circuit,
+		...len(9, [...num(1, 1), ...circuit]),
+		...num(30, 140),
+	])
+
+	expect(bytes).toEqual([
+		...num(1, 9),
+		...len(2, [
+			...num(3, 7),
+			...len(14, [...num(1, 4), ...num(6, 2)]),
+			...len(7, len(8, num(1, 1))),
+		]),
+		...len(9, num(1, 1)),
+		...num(30, 123),
+	])
+	expect(stats).toMatchObject({
+		schemaVersion: 9,
+		originalVersion: 140,
+		versionPatched: true,
+		objectBlobs: 1,
+		objectsModified: 1,
+		fn100Removed: 1,
+		fn5Removed: 1,
+		circuitFieldsRemoved: 4,
+	})
+	expect(stats.inputBytes - stats.outputBytes).toBeGreaterThan(stats.circuitBytesRemoved)
+})
+
+it('keeps an fn100 that is not the sentinel, and only patches the first fn30', () => {
+	const input = [...len(2, num(100, 5)), ...num(30, 123), ...num(30, 200)]
+	const { bytes, stats } = run(input)
+	expect(bytes).toEqual(input)
+	expect(stats).toMatchObject({ fn100Removed: 0, objectsModified: 0, versionPatched: false })
+})
+
+it('leaves bytes that only look like a circuit field alone', () => {
+	// 0xE2 is a field-28 tag, but the string around it doesn't parse as a message end to
+	// end, so it is opaque and must survive untouched.
+	const input = len(3, [0xe2, 0x01, 0x02, 0x41, 0x42, 0xff])
+	expect(run(input).bytes).toEqual(input)
+})
+
+it('copies a truncated file through instead of throwing', () => {
+	const input = [...num(1, 9), ...len(2, num(3, 7)).slice(0, -1)]
+	expect(run(input).bytes).toEqual(input)
+	expect(run([]).bytes).toEqual([])
+})