Custom matcher for testing-library/* to find text broken up by elements

matchTextAcrossElements.ts

/**
 * A TextMatch (see https://testing-library.com/docs/queries/about#textmatch)
 * which will match a text string broken across multiple elements.
 * Useful for finding, e.g. "hello there" in <p>hello <b>there</b></p>
 */
export const matchTextAcrossElements =
    (text: string) => (content: string, element: Element | null) => {
        const hasText = (element) => element.textContent === text;

        const elementHasText = hasText(element);
        const childrenDontHaveText = Array.from(element?.children || []).every(
            (child) => !hasText(child)
        );
        return elementHasText && childrenDontHaveText;
    };