Merge pull request #69 from x0k/port-4461

[core] Port rjsf-team/react-jsonschema-form#4461

Author: x0k

.changeset/purple-birds-repeat.md

@@ -0,0 +1,5 @@
+---
+"@sjsf/form": patch
+---
+
+Port https://github.com/rjsf-team/react-jsonschema-form/pull/4461

packages/form/src/core/merge.test.ts

@@ -442,14 +442,46 @@ describe("mergeDefaultsWithFormData()", () => {
     expect(mergeDefaultsWithFormData({}, undefined)).toEqual(undefined);
   });
 
+  it("should deeply merge and return formData when formData is undefined and defaultSupercedesUndefined false", () => {
+    expect(
+      mergeDefaultsWithFormData(
+        {
+          arrayWithDefaults: ["Hello World"],
+          objectWidthDefaults: {
+            nestedField: "Hello World!",
+          },
+          stringField: "Hello World!!",
+        },
+        {
+          arrayWithDefaults: [null],
+          objectWidthDefaults: {
+            nestedField: undefined,
+          },
+          stringField: undefined,
+          nonEmptyField: "Hello World!!!",
+        },
+        undefined,
+        undefined,
+        true
+      )
+    ).toEqual({
+      arrayWithDefaults: [null],
+      objectWidthDefaults: {
+        nestedField: undefined,
+      },
+      stringField: undefined,
+      nonEmptyField: "Hello World!!!",
+    });
+  });
+
   it("should return default when formData is undefined and defaultSupercedesUndefined true", () => {
     expect(mergeDefaultsWithFormData({}, undefined, undefined, true)).toEqual(
       {}
     );
   });
 
   it("should return default when formData is null and defaultSupercedesUndefined true", () => {
-    expect(mergeDefaultsWithFormData({}, null, undefined, true)).toEqual({})
+    expect(mergeDefaultsWithFormData({}, null, undefined, true)).toEqual({});
   });
 
   it("should return undefined when formData is undefined", () => {

packages/form/src/core/merge.ts

@@ -137,7 +137,7 @@ export function mergeDefaultsWithFormData<T = any>(
       : defaultsArray;
 
     const mapped = overrideArray.map((value, idx) => {
-      if (overrideOppositeArray[idx]) {
+      if (overrideOppositeArray[idx] !== undefined) {
         return mergeDefaultsWithFormData<any>(
           defaultsArray[idx],
           formData[idx],