Override the formData with the const if the constAsDefaults is set to always

Author: abdalla-rko

packages/utils/src/schema/getDefaultFormState.ts

@@ -331,7 +331,13 @@ export function computeDefaults<T = any, S extends StrictRJSFSchema = RJSFSchema
     const { arrayMinItems = {} } = experimental_defaultFormStateBehavior || {};
     const { mergeExtraDefaults } = arrayMinItems;
 
-    const matchingFormData = ensureFormDataMatchingSchema(validator, schema, rootSchema, rawFormData);
+    const matchingFormData = ensureFormDataMatchingSchema(
+      validator,
+      schema,
+      rootSchema,
+      rawFormData,
+      experimental_defaultFormStateBehavior
+    );
     if (!isObject(rawFormData)) {
       defaultsWithFormData = mergeDefaultsWithFormData<T>(
         defaultsWithFormData as T,
@@ -351,21 +357,34 @@ export function computeDefaults<T = any, S extends StrictRJSFSchema = RJSFSchema
  * @param schema - The schema for which the formData state is desired
  * @param rootSchema - The root schema, used to primarily to look up `$ref`s
  * @param formData - The current formData
+ * @param experimental_defaultFormStateBehavior - Optional configuration object, if provided, allows users to override default form state behavior
  * @returns - valid formData that matches schema
  */
 export function ensureFormDataMatchingSchema<
   T = any,
   S extends StrictRJSFSchema = RJSFSchema,
   F extends FormContextType = any
->(validator: ValidatorType<T, S, F>, schema: S, rootSchema: S, formData: T | undefined): T | T[] | undefined {
+>(
+  validator: ValidatorType<T, S, F>,
+  schema: S,
+  rootSchema: S,
+  formData: T | undefined,
+  experimental_defaultFormStateBehavior?: Experimental_DefaultFormStateBehavior
+): T | T[] | undefined {
   const isSelectField = !isConstant(schema) && isSelect(validator, schema, rootSchema);
   let validFormData: T | T[] | undefined = formData;
-
   if (isSelectField) {
     const getOptionsList = optionsList(schema);
     const isValid = getOptionsList?.some((option) => isEqual(option.value, formData));
     validFormData = isValid ? formData : undefined;
   }
+
+  // Override the formData with the const if the constAsDefaults is set to always
+  const constTakesPrecedence = schema[CONST_KEY] && experimental_defaultFormStateBehavior?.constAsDefaults === 'always';
+  if (constTakesPrecedence) {
+    validFormData = schema.const as any;
+  }
+
   return validFormData;
 }
 

packages/utils/test/schema/getDefaultFormStateTest.ts

@@ -48,6 +48,7 @@ type ObjectDefaultExpectList = [
   IExpectType,
   IExpectType,
   IExpectType,
+  IExpectType,
   IExpectType
 ];
 
@@ -620,6 +621,26 @@ const testObjectDefault = (testValidator: TestValidatorType, expectList: ObjectD
         },
       });
     });
+    it('Test an object with invalid formData const and constAsDefault set to always', () => {
+      schema = {
+        type: 'object',
+        properties: {
+          stringField: {
+            type: 'string',
+            const: 'fromConst',
+          },
+        },
+      };
+
+      validateBasedOnIndex(24, expectList, schema, {
+        rawFormData: {
+          stringField: 'fromFormData',
+        },
+        experimental_defaultFormStateBehavior: {
+          constAsDefaults: 'always',
+        },
+      });
+    });
   });
 };
 
@@ -976,6 +997,20 @@ export default function getDefaultFormStateTest(testValidator: TestValidatorType
           ),
         toEqual: {},
       },
+      {
+        expectedCB: (schema, options) =>
+          getDefaultFormState(
+            testValidator,
+            schema,
+            options.rawFormData,
+            schema,
+            undefined,
+            options.experimental_defaultFormStateBehavior
+          ),
+        toEqual: {
+          stringField: 'fromConst',
+        },
+      },
     ]);
     // test array defaults
     testArrayDefault(testValidator, [
@@ -1356,6 +1391,16 @@ export default function getDefaultFormStateTest(testValidator: TestValidatorType
             }),
           toEqual: {},
         },
+        {
+          expectedCB: (schema, options) =>
+            computeDefaults(testValidator, schema, {
+              rootSchema: schema,
+              ...options,
+            }),
+          toEqual: {
+            stringField: 'fromConst',
+          },
+        },
       ]);
       // test array defaults
       testArrayDefault(testValidator, [
@@ -1663,6 +1708,16 @@ export default function getDefaultFormStateTest(testValidator: TestValidatorType
             }),
           toEqual: {},
         },
+        {
+          expectedCB: (schema, options) =>
+            getDefaultBasedOnSchemaType(testValidator, schema, {
+              rootSchema: schema,
+              ...options,
+            }),
+          toEqual: {
+            stringField: 'fromConst',
+          },
+        },
       ]);
       // test array defaults
       testArrayDefault(testValidator, [
@@ -1985,6 +2040,16 @@ export default function getDefaultFormStateTest(testValidator: TestValidatorType
             }),
           toEqual: {},
         },
+        {
+          expectedCB: (schema, options) =>
+            getObjectDefaults(testValidator, schema, {
+              rootSchema: schema,
+              ...options,
+            }),
+          toEqual: {
+            stringField: 'fromConst',
+          },
+        },
       ]);
     });
     describe('getArrayDefaults()', () => {