fix: FixedPointNumber.eq() used multiplication instead of exponentiation

src/architecture/FixedPointNumber.ts

@@ -149,7 +149,7 @@ export class FixedPointNumber implements IFixedPointNumber {
   eq(value: FixedPointNumberValue): boolean {
     if (value instanceof FixedPointNumber) {
       if (this.scale > value.scale) {
-        return this.value === value.value * BigInt(10) * (this.scale - value.scale);
+        return this.value === value.value * BigInt(10) ** (this.scale - value.scale);
       }
       return this.value * BigInt(10) ** (value.scale - this.scale) === value.value;
     }

src/architecture/__tests__/FixedPointNumber.test.ts

@@ -0,0 +1,35 @@
+import { FixedPointNumber } from '../FixedPointNumber';
+
+describe('FixedPointNumber.eq', () => {
+  it('returns true for equal values with the same scale', () => {
+    expect(new FixedPointNumber(500, 2).eq(new FixedPointNumber(500, 2))).toBe(true);
+  });
+
+  it('returns true for equal values when this.scale > value.scale', () => {
+    expect(new FixedPointNumber(500, 2).eq(new FixedPointNumber(5, 0))).toBe(true);
+  });
+
+  it('returns true for equal values when this.scale < value.scale', () => {
+    expect(new FixedPointNumber(5, 0).eq(new FixedPointNumber(500, 2))).toBe(true);
+  });
+
+  it('returns false for different values when this.scale > value.scale', () => {
+    expect(new FixedPointNumber(501, 2).eq(new FixedPointNumber(5, 0))).toBe(false);
+  });
+
+  it('returns false for different values when this.scale < value.scale', () => {
+    expect(new FixedPointNumber(5, 0).eq(new FixedPointNumber(501, 2))).toBe(false);
+  });
+
+  it('stays consistent with lt/gt for the same scale-mismatched pair', () => {
+    const a = new FixedPointNumber(500, 2);
+    const b = new FixedPointNumber(5, 0);
+    expect(a.eq(b)).toBe(true);
+    expect(a.lt(b)).toBe(false);
+    expect(a.gt(b)).toBe(false);
+  });
+
+  it('handles a larger scale delta correctly', () => {
+    expect(new FixedPointNumber(5000000, 6).eq(new FixedPointNumber(5, 0))).toBe(true);
+  });
+});