From fb5c3161d0ec485c28ce973c657f18c07e6a6986 Mon Sep 17 00:00:00 2001
From: youchao liu <ryuforever@163.com>
Date: Wed, 5 Feb 2020 00:50:43 +0800
Subject: [PATCH] fix: patches when delete object property in array

---
 __tests__/patch.js | 15 +++++++++++++++
 src/es5.ts         | 15 +++++++++++----
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/__tests__/patch.js b/__tests__/patch.js
index f74dd5de..8eab494e 100644
--- a/__tests__/patch.js
+++ b/__tests__/patch.js
@@ -648,6 +648,21 @@ describe("arrays - splice (shrink)", () => {
 	)
 })
 
+describe.only("arrays - delete", () => {
+	runPatchTest(
+		{
+			x: [
+				{a: 1, b: 2},
+				{c: 3, d: 4}
+			]
+		},
+		d => {
+			delete d.x[1].c
+		},
+		[{op: "remove", path: ["x", 1, "c"]}]
+	)
+})
+
 describe("sets - add - 1", () => {
 	runPatchTest(
 		new Set([1]),
diff --git a/src/es5.ts b/src/es5.ts
index 7cd58e20..159e5fad 100644
--- a/src/es5.ts
+++ b/src/es5.ts
@@ -241,15 +241,22 @@ function markChangesRecursively(object: any) {
 				markChangedES5(state)
 			}
 		})
-	} else if (type === ProxyType.ES5Array && hasArrayChanges(state)) {
-		markChangedES5(state)
-		assigned.length = true
+	} else if (type === ProxyType.ES5Array) {
+		if (hasArrayChanges(state)) {
+			markChangedES5(state)
+			assigned.length = true
+		}
+
 		if (draft.length < base.length) {
 			for (let i = draft.length; i < base.length; i++) assigned[i] = false
 		} else {
 			for (let i = base.length; i < draft.length; i++) assigned[i] = true
 		}
-		for (let i = 0; i < draft.length; i++) {
+
+		// Minimum count is enough, the other parts has been processed.
+		const min = Math.min(draft.length, base.length)
+
+		for (let i = 0; i < min; i++) {
 			// Only untouched indices trigger recursion.
 			if (assigned[i] === undefined) markChangesRecursively(draft[i])
 		}