Fail jest test suite if console error count increases - jestjs

Question

We want to fail the build if more console errors are introduced. For example, let's say console.error was called 30 times in the whole test suite. If another error is introduced this will increase to 31, which we don't want. Is there a way to prevent this?
For one test suite it is possible with:
const spy = jest.spyOn(console, "error");
let count = 0;
afterEach(() => {
count += spy.mock.calls.length;
});
afterAll(() => {
if (count > 2) {
throw Error(`oops error count: ${count}`);
}
});
but it would be nice to have this globally defined.

Answer 1

We solved this in a slightly different way:
// src/utils/testUtils
let consoleErrorSpy;
export const spyOnConsoleError = () => {
consoleErrorSpy = jest.spyOn(console, "error");
};
/**
* We are using this to prevent the console errors from increasing.
* These are our preferences in order of priority:
* 1. Don't call this method
* 2. Call this method at the end of a specific test (eg. for an error that can't be solved)
* 3. Call this method in `afterEach` (eg. for an async error that can't be solved)
*/
export const catchConsoleErrors = ({ silenced = [] } = {}) => {
const alwaysSilencedErrors = [
'<bug from a 3rd party library>'
];
const forbiddenCalls = [];
const silencedCalls = [];
for (const call of consoleErrorSpy.mock.calls) {
if (
new RegExp([...alwaysSilencedErrors, ...silenced].join("|")).test(call)
) {
silencedCalls.push(call);
} else {
forbiddenCalls.push(call);
}
}
for (const silencedCall of silencedCalls) {
// eslint-disable-next-line no-console
console.log("SILENCED\n---\n" + silencedCall.join(",") + "\n---");
}
expect(forbiddenCalls).toHaveLength(0);
// We clear the mock here so nothing happens if the method is called again for the same test,
// which is the case when this method is called in a specific test (file)
// as it is also called in `afterEach` in setUpTests.js
consoleErrorSpy.mockClear();
};
// some test file
afterEach(() => {
catchConsoleErrors({
silenced: [
"Warning: Can't perform a React state update on an unmounted component.*"
]
});
});
// src/setupTests.js
spyOnConsoleError();
afterEach(() => {
catchConsoleErrors();
});