fix: comparison typo

This bug prevented Immer from _not_ generating a "replace" patch when the new value is identical to the old value.

Author: aleclarson

__tests__/patch.js

@@ -292,8 +292,7 @@ describe("same value replacement - 2", () => {
             d.x = 4
             d.x = a
         },
-        // immer does not detect this is not an actual change
-        [{op: "replace", path: ["x"], value: {y: 3}}]
+        []
     )
 })
 
@@ -314,8 +313,7 @@ describe("same value replacement - 4", () => {
             d.x = 4
             d.x = 3
         },
-        // immer does not detect this is not an actual change
-        [{op: "replace", path: ["x"], value: 3}]
+        []
     )
 })
 

src/patches.js

@@ -58,7 +58,7 @@ function generateObjectPatches(state, basePath, patches, inversePatches) {
         const origValue = base[key]
         const value = copy[key]
         const op = !assignedValue ? "remove" : key in base ? "replace" : "add"
-        if (origValue === base && op === "replace") return
+        if (origValue === value && op === "replace") return
         const path = basePath.concat(key)
         patches.push(op === "remove" ? {op, path} : {op, path, value})
         inversePatches.push(