Add large object perf test (from #941)

__performance_tests__/large-obj.js

@@ -0,0 +1,60 @@
+import {measure} from "./measure"
+import {
+	produce,
+	setUseProxies,
+	setUseStrictShallowCopy
+} from "../dist/immer.cjs.production.min.js"
+
+console.log("\n# large-obj - mutate large object\n")
+
+const MAX = 50
+
+const baseState = Object.fromEntries(
+	Array(10000)
+		.fill(0)
+		.map((_, i) => [i, i])
+)
+
+measure("immer (proxy) - with setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(true)
+	setUseProxies(true)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (proxy) - without setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(false)
+	setUseProxies(true)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (es5) - with setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(true)
+	setUseProxies(false)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})
+
+measure("immer (es5) - without setUseStrictShallowCopy", () => {
+	setUseStrictShallowCopy(false)
+	setUseProxies(false)
+
+	for (let i = 0; i < MAX; i++) {
+		produce(baseState, draft => {
+			draft[5000]++
+		})
+	}
+})