Function _valueAsString

src/cdk/testing/component-harness.ts:729–753

Represent a value as a string for the purpose of logging.

(value: unknown)

/** Represent a value as a string for the purpose of logging. */
function _valueAsString(value: unknown) {
  if (value === undefined) {
    return 'undefined';
  }
  try {
    // `JSON.stringify` doesn't handle RegExp properly, so we need a custom replacer.
    // Use a character that is unlikely to appear in real strings to denote the start and end of
    // the regex. This allows us to strip out the extra quotes around the value added by
    // `JSON.stringify`. Also do custom escaping on `"` characters to prevent `JSON.stringify`
    // from escaping them as if they were part of a string.
    const stringifiedValue = JSON.stringify(value, (_, v) =>
      v instanceof RegExp
        ? `◬MAT_RE_ESCAPE◬${v.toString().replace(/"/g, '◬MAT_RE_ESCAPE◬')}◬MAT_RE_ESCAPE◬`
        : v,
    );
    // Strip out the extra quotes around regexes and put back the manually escaped `"` characters.
    return stringifiedValue
      .replace(/"◬MAT_RE_ESCAPE◬|◬MAT_RE_ESCAPE◬"/g, '')
      .replace(/◬MAT_RE_ESCAPE◬/g, '"');
  } catch {
    // `JSON.stringify` will throw if the object is cyclical,
    // in this case the best we can do is report the value as `{...}`.
    return '{...}';
  }
}

/**
 * Splits up a compound selector into its parts and escapes any quoted content. The quoted content