fixed bigint serialization

src/token/fungible/TokenCoinData.ts

@@ -57,8 +57,24 @@ export class TokenCoinData implements ISerializable {
     }
 
     const coins: [bigint, bigint][] = [];
+
+    // Helper function to safely parse values that might have been corrupted by JSON.stringify()
+    const parseValue = (v: unknown): bigint => {
+      if (typeof v === 'bigint') return v;
+      if (typeof v === 'string' || typeof v === 'number') return BigInt(v);
+      if (v === null) {
+        throw new Error(`Cannot convert null to BigInt. This indicates a JSON serialization issue with BigInt values.`);
+      }
+      if (typeof v === 'object') {
+        throw new Error(
+          `Cannot convert object to BigInt. This indicates a JSON serialization issue with BigInt values. Received: ${JSON.stringify(v)}`,
+        );
+      }
+      throw new Error(`Unsupported type for BigInt conversion: ${typeof v}. Expected string, number, or bigint.`);
+    };
+
     for (const [key, value] of data) {
-      coins.push([BigInt(key), BigInt(value)]);
+      coins.push([parseValue(key), parseValue(value)]);
     }
 
     return new TokenCoinData(coins);

tests/unit/token/fungible/TokenCoinDataBigIntTest.ts

@@ -0,0 +1,86 @@
+import { TokenCoinData } from '../../../../src/token/fungible/TokenCoinData.js';
+
+describe('TokenCoinData BigInt JSON Serialization', () => {
+  it('should handle normal JSON serialization correctly', () => {
+    const coinData = new TokenCoinData([
+      [123n, 456n],
+      [789n, 101112n],
+    ]);
+    const json = coinData.toJSON();
+    const restored = TokenCoinData.fromJSON(json);
+
+    expect(restored.getByKey(123n)).toBe(456n);
+    expect(restored.getByKey(789n)).toBe(101112n);
+  });
+
+  it('should provide clear error message for object types from JSON.stringify BigInt corruption', () => {
+    // Simulate what happens when JSON.stringify converts BigInt to {}
+    const corruptedData = [{}, {}];
+
+    expect(() => {
+      TokenCoinData.fromJSON([corruptedData]);
+    }).toThrow(
+      'Cannot convert object to BigInt. This indicates a JSON serialization issue with BigInt values. Received: {}',
+    );
+  });
+
+  it('should handle string values correctly', () => {
+    const stringData = [
+      ['123', '456'],
+      ['789', '101112'],
+    ];
+    const restored = TokenCoinData.fromJSON(stringData);
+
+    expect(restored.getByKey(123n)).toBe(456n);
+    expect(restored.getByKey(789n)).toBe(101112n);
+  });
+
+  it('should handle number values correctly', () => {
+    const numberData = [
+      [123, 456],
+      [789, 101112],
+    ];
+    const restored = TokenCoinData.fromJSON(numberData);
+
+    expect(restored.getByKey(123n)).toBe(456n);
+    expect(restored.getByKey(789n)).toBe(101112n);
+  });
+
+  it('should handle BigInt values correctly', () => {
+    const bigintData = [
+      [123n, 456n],
+      [789n, 101112n],
+    ];
+    const restored = TokenCoinData.fromJSON(bigintData);
+
+    expect(restored.getByKey(123n)).toBe(456n);
+    expect(restored.getByKey(789n)).toBe(101112n);
+  });
+
+  it('should provide helpful error for undefined values', () => {
+    const undefinedData = [[undefined, '456']];
+
+    expect(() => {
+      TokenCoinData.fromJSON(undefinedData);
+    }).toThrow('Unsupported type for BigInt conversion: undefined. Expected string, number, or bigint.');
+  });
+
+  it('should provide helpful error for null values', () => {
+    const nullData = [[null, '456']];
+
+    expect(() => {
+      TokenCoinData.fromJSON(nullData);
+    }).toThrow('Cannot convert null to BigInt. This indicates a JSON serialization issue with BigInt values.');
+  });
+
+  it('should handle mixed valid types', () => {
+    const mixedData = [
+      ['123', 456],
+      [789n, '101112'],
+    ];
+    const restored = TokenCoinData.fromJSON(mixedData);
+
+    expect(restored.getByKey(123n)).toBe(456n);
+    expect(restored.getByKey(789n)).toBe(101112n);
+  });
+});