Add support for non-indexed array fields #8

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to the library will be documented in this file.
 ## vX.X.X (Month DD, YYYY)
 
 - Add `FormDataInfo` type to global exports
+- Add support for non-indexed array fields (issue #8)
 
 ## v0.4.0 (November 12, 2023)
 

src/decode.test.ts

@@ -60,7 +60,7 @@ describe('decode', () => {
     expect(decode(formData, { files: ['file'] })).toEqual({ file });
   });
 
-  test('should decode arrays', () => {
+  test('should decode indexed arrays', () => {
     const formData = new FormData();
     formData.append('array.0', 'index_0');
     formData.append('array.1', 'index_1');
@@ -70,6 +70,20 @@ describe('decode', () => {
     });
   });
 
+  test('should decode non-indexed arrays', () => {
+    const formData = new FormData();
+    formData.append('array', 'index_0');
+    formData.append('array', 'index_1');
+    formData.append('array', 'index_2');
+    expect(
+      decode(formData, {
+        arrays: ['array'],
+      })
+    ).toEqual({
+      array: ['index_0', 'index_1', 'index_2'],
+    });
+  });
+
   test('should decode objects', () => {
     const formData = new FormData();
     formData.append('nested.string', 'hello');

src/decode.ts

@@ -46,7 +46,21 @@ export function decode<
         !info?.files?.includes(templateName) ||
         (value && (typeof value === 'string' || value.size))
       ) {
-        object[key] = getFieldValue(info, templateName, value);
+        // Get field value
+        const fieldValue = getFieldValue(info, templateName, value);
+
+        // If it is an non-indexed array, add value to array
+        if (info?.arrays?.includes(templateName)) {
+          if (object[key]) {
+            object[key].push(fieldValue);
+          } else {
+            object[key] = [fieldValue];
+          }
+
+          // Otherwise, add value directly to key
+        } else {
+          object[key] = fieldValue;
+        }
       }
     }, values);
   }