fix fromFields for DynamicArray

Author: phn210

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@auxo-dev/auxo-libs",
-  "version": "0.2.8",
+  "version": "0.2.9",
   "description": "",
   "author": "",
   "license": "Apache-2.0",

src/DynamicArray.test.ts

@@ -55,9 +55,7 @@ describe('DynamicArray', () => {
     );
     fieldDeserialized.length.assertEquals(fieldArray.length);
     for (let i = 0; i < fieldArray.values.length; i++) {
-      (fieldDeserialized as DynamicFieldArray)
-        .get(Field(i))
-        .assertEquals(fieldArray.get(Field(i)));
+      fieldDeserialized.get(Field(i)).assertEquals(fieldArray.get(Field(i)));
     }
 
     // Group
@@ -69,9 +67,7 @@ describe('DynamicArray', () => {
     );
     groupDeserialized.length.assertEquals(groupArray.length);
     for (let i = 0; i < groupArray.values.length; i++) {
-      (groupDeserialized as DynamicGroupArray)
-        .get(Field(i))
-        .assertEquals(groupArray.get(Field(i)));
+      groupDeserialized.get(Field(i)).assertEquals(groupArray.get(Field(i)));
     }
 
     // Scalar
@@ -86,9 +82,7 @@ describe('DynamicArray', () => {
     );
     scalarDeserialized.length.assertEquals(scalarArray.length);
     for (let i = 0; i < scalarArray.values.length; i++) {
-      (scalarDeserialized as DynamicScalarArray)
-        .get(Field(i))
-        .assertEquals(scalarArray.get(Field(i)));
+      scalarDeserialized.get(Field(i)).assertEquals(scalarArray.get(Field(i)));
     }
   });
 });

src/DynamicArray.ts

@@ -45,7 +45,6 @@ export function PublicKeyDynamicArray(maxLength: number) {
 
 export function DynamicArray<T>(type: ProvablePure<T>, maxLength: number) {
   const _type = hashable(type);
-
   return class _DynamicArray extends Struct({
     length: Field,
     values: Provable.Array(type, maxLength),
@@ -54,6 +53,22 @@ export function DynamicArray<T>(type: ProvablePure<T>, maxLength: number) {
       return new _DynamicArray(values);
     }
 
+    static fromFields(fields: Field[]): _DynamicArray {
+      let length = fields[0];
+      let sizeInFields = type.sizeInFields();
+      let values: T[] = [];
+      Provable.asProver(() => {
+        for (let i = 0; i < Number(length); i++) {
+          values.push(
+            type.fromFields(
+              fields.slice(1 + sizeInFields * i, 1 + sizeInFields * (i + 1))
+            )
+          );
+        }
+      });
+      return new _DynamicArray(values);
+    }
+
     static empty(length?: Field): _DynamicArray {
       const arr = new _DynamicArray();
       arr.length = length ?? Field(0);