test: add missing test coverage to boolean coder throw conditions

packages/abi-coder/src/coders/boolean.test.ts

@@ -1,5 +1,12 @@
+import * as mathMod from '@fuel-ts/math';
+
 import BooleanCoder from './boolean';
 
+jest.mock('@fuel-ts/math', () => ({
+  __esModule: true,
+  ...jest.requireActual('@fuel-ts/math'),
+}));
+
 describe('BooleanCoder', () => {
   const TRUE_DECODED = true;
   const TRUE_ENCODED = new Uint8Array([0, 0, 0, 0, 0, 0, 0, 1]);
@@ -40,6 +47,26 @@ describe('BooleanCoder', () => {
     expect(actualLength).toBe(expectedLength);
   });
 
+  it('should throw an error when encoding an invalid boolean value', () => {
+    const toBytesSpy = jest
+      .spyOn(mathMod, 'toBytes')
+      .mockReturnValueOnce(new Uint8Array([0, 0, 0, 0, 0, 0, 0, 1]));
+
+    expect(() => {
+      coder.encode(TRUE_DECODED);
+    }).toThrow('Invalid bool');
+  });
+
+  it('should throw an error when input to encode cannot be converted to bytes', () => {
+    const toBytesSpy = jest.spyOn(mathMod, 'toBytes').mockImplementationOnce(() => {
+      throw new Error();
+    });
+
+    expect(() => {
+      coder.encode(TRUE_DECODED);
+    }).toThrow('Invalid bool');
+  });
+
   it('should throw an error when decoding an invalid boolean value', () => {
     const invalidInput = new Uint8Array([0, 0, 0, 0, 0, 0, 0, 2]);