I am trying to test my circom circuit but am getting errors.

Generating the witness using let witness = await circuit.calculateWitness({ a: inputA, b: inputB }); works as expected.

Then I am trying these two functions but I get errors:
await circuit.getDecoratedOutput(witness) gives ReferenceError: utils is not defined

and
await circuit.assertOut(witness, expectedOutput) gives AssertionError: Output variable not defined: main[0]

I have no idea what this means and how to fix it. Does someone have any idea?