From 50fdc0b4c9ab36933e6a0c9288fef3ac5df2b907 Mon Sep 17 00:00:00 2001
From: Evan Phoenix <evan@phx.io>
Date: Thu, 21 Oct 2021 09:40:42 -0700
Subject: [PATCH] port over fix for testing/replacing a whole document to v4

---
 patch.go      | 42 ++++++++++++++++++++++++++++++++++++++++++
 patch_test.go | 30 ++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/patch.go b/patch.go
index 4bce593..dc2b7e5 100644
--- a/patch.go
+++ b/patch.go
@@ -568,6 +568,29 @@ func (p Patch) replace(doc *container, op Operation) error {
 		return errors.Wrapf(err, "replace operation failed to decode path")
 	}
 
+	if path == "" {
+		val := op.value()
+
+		if val.which == eRaw {
+			if !val.tryDoc() {
+				if !val.tryAry() {
+					return errors.Wrapf(err, "replace operation value must be object or array")
+				}
+			}
+		}
+
+		switch val.which {
+		case eAry:
+			*doc = &val.ary
+		case eDoc:
+			*doc = &val.doc
+		case eRaw:
+			return errors.Wrapf(err, "replace operation hit impossible case")
+		}
+
+		return nil
+	}
+
 	con, key := findObject(doc, path)
 
 	if con == nil {
@@ -634,6 +657,25 @@ func (p Patch) test(doc *container, op Operation) error {
 		return errors.Wrapf(err, "test operation failed to decode path")
 	}
 
+	if path == "" {
+		var self lazyNode
+
+		switch sv := (*doc).(type) {
+		case *partialDoc:
+			self.doc = *sv
+			self.which = eDoc
+		case *partialArray:
+			self.ary = *sv
+			self.which = eAry
+		}
+
+		if self.equal(op.value()) {
+			return nil
+		}
+
+		return errors.Wrapf(ErrTestFailed, "testing value %s failed", path)
+	}
+
 	con, key := findObject(doc, path)
 
 	if con == nil {
diff --git a/patch_test.go b/patch_test.go
index 22db16f..84e2996 100644
--- a/patch_test.go
+++ b/patch_test.go
@@ -231,6 +231,36 @@ var Cases = []Case{
 		   { "op": "copy", "path": "/foo/-", "from": "/foo/1" }]`,
 		fmt.Sprintf(`{ "foo": ["A", %q, %q, %q] }`, repeatedA(48), repeatedA(48), repeatedA(48)),
 	},
+	{
+		`{
+      "id": "00000000-0000-0000-0000-000000000000",
+      "parentID": "00000000-0000-0000-0000-000000000000"
+		}`,
+		`[
+ {
+   "op": "test",
+   "path": "",
+   "value": {
+     "id": "00000000-0000-0000-0000-000000000000",
+     "parentID": "00000000-0000-0000-0000-000000000000"
+   }
+ },
+ {
+   "op": "replace",
+   "path": "",
+   "value": {
+     "id": "759981e8-ec68-4639-a83e-513225914ecb",
+     "originalID": "bar",
+     "parentID": "00000000-0000-0000-0000-000000000000"
+   }
+ }
+		]`,
+		`{
+ "id" : "759981e8-ec68-4639-a83e-513225914ecb",
+ "originalID" : "bar",
+ "parentID" : "00000000-0000-0000-0000-000000000000"
+		}`,
+	},
 }
 
 type BadCase struct {