feat: add warning for invalid precision in BN format method

.changeset/warn-precision-validation

@@ -0,0 +1,5 @@
+---
+"@fuel-ts/math": patch
+---
+
+feat: add warning for invalid precision in `BN` format method

packages/math/src/bn.test.ts

@@ -541,4 +541,35 @@ describe('Math - BN', () => {
   it('should return significant figures even if it exceeds the precision', () => {
     expect(bn('4000000').format({ precision: 1 })).toEqual('0.004');
   });
+
+  describe('precision validation', () => {
+    let consoleWarnSpy: jest.SpyInstance;
+
+    beforeEach(() => {
+      consoleWarnSpy = jest.spyOn(console, 'warn').mockImplementation();
+    });
+
+    afterEach(() => {
+      consoleWarnSpy.mockRestore();
+    });
+
+    it('should warn when precision is less than minPrecision', () => {
+      bn(123).format({ precision: 2, minPrecision: 4 });
+
+      expect(consoleWarnSpy).toHaveBeenCalledWith(
+        'Warning: precision (2) is less than minPrecision (4). ' +
+        'This may lead to unexpected behavior. Consider setting precision >= minPrecision.'
+      );
+    });
+
+    it('should not warn when precision equals minPrecision', () => {
+      bn(123).format({ precision: 4, minPrecision: 4 });
+      expect(consoleWarnSpy).not.toHaveBeenCalled();
+    });
+
+    it('should not warn when precision is greater than minPrecision', () => {
+      bn(123).format({ precision: 6, minPrecision: 4 });
+      expect(consoleWarnSpy).not.toHaveBeenCalled();
+    });
+  });
 });

packages/math/src/bn.ts

@@ -117,8 +117,15 @@ export class BN extends BnJs implements BNInputOverrides, BNHiddenTypes, BNHelpe
       return this.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ',');
     }
 
-    // Adjust precision and minPrecision
-    // TODO: This really should throw an error because you can't have a precision less than the minPrecision but this would be a breaking change
+    // Warn if precision is less than minPrecision
+    if (initialPrecision < initialMinPrecision) {
+      console.warn(
+        `Warning: precision (${initialPrecision}) is less than minPrecision (${initialMinPrecision}). ` +
+        'This may lead to unexpected behavior. Consider setting precision greater than or equal to minPrecision.'
+      );
+    }
+
+    // Adjust precision and minPrecision to maintain backward compatibility
     const minPrecision =
       initialMinPrecision > initialPrecision ? initialPrecision : initialMinPrecision;
     const precision =