How can I verify a call to a stub which is configured to throw?

[benblank]

Description

I need to verify that a stub was called with a particular parameter, but also have that stub throw an error.

Issue

When a stub is configured to throw, attempting to verify it instead throws the configured error. (Also, my current attempt uses both .when and .verify on the same stub, which the docs suggest is incorrect anyway.)

Environment

• node -v output: v10.8.0
• npm -v (or yarn --version) output: 1.12.1
• npm ls testdouble (or yarn list testdouble) version:
  yarn list v1.12.1
  warning Filtering by arguments is deprecated. Please use the pattern option instead.
  └─ testdouble@3.11.0
  ✨ Done in 0.56s.

Code-fenced Example

const assert = require('assert').strict;
const execa = require('execa');
const td = require('testdouble');

function subject() {
  try {
    const { stdout } = execa('foo');  // throws if "foo" doesn't exist or has a non-zero exit code
    const match = /some (.+) string/.exec(stdout);

    return match[1];
  } catch (ex) {
    // log it
  }

  try {
    const { stdout } = execa('bar');  // throws if "bar" doesn't exist or has a non-zero exit code
    const match = /a different (.+) string/.exec(stdout);

    return match[1];
  } catch (ex) {
    // log it

    return null;
  }
}

const stub = td.function(execa.sync);

td.replace(execa, 'sync', stub);
td.when(stub(), { ignoreExtraArgs: true }).thenThrow(new Error('command not found'));

assert(null === subject());

td.verify(stub('bar'), { ignoreExtraArgs: true });  // throws "command not found" error

How should I instead be configuring/verifying this stub?

[searls]

This wouldn't be supported, as it falls under our advice not to verify what you stub. If the stubbing to throw an error is necessary, then an explicit verification would be redundant, as the stubbing would either be observable by the test directly (e.g. an error is thrown, as is the case here), or indirectly (the subject handles the error somehow and whatever it does next is asserted by the test).

For more commentary, see this FAQ