23 replies

Best Practices for Error Checking in Code Testing

What is the best practice when checking for errors in a test?

I have some code that I want to test. In my test I run the effect to obtain an

Exit

Exit

const result = Effect.runSyncExit(
    // run my code here
);

const result = Effect.runSyncExit(
    // run my code here
);

I figured that there is a type guard to determine if my

Exit

Exit

is a failure:

Exit.isFailure(result)

Exit.isFailure(result)

but within it there is a

Cause

Cause

with multiple options and

Cause.isFailure

Cause.isFailure

is not a type guard. How do I extract my actual

Error

Error

from an

Exit

Exit

? This is where I'm at:

if (Exit.isFailure(result) && Cause.isFailure(result.cause)) {
    // oops, no access to the error
} else {
    fail("Expected an error.");
}

if (Exit.isFailure(result) && Cause.isFailure(result.cause)) {
    // oops, no access to the error
} else {
    fail("Expected an error.");
}