Function makePrintable

src/util/log.ts:77–123

(...hintInfo: unknown[])

 * @throws Error
 */
export function makePrintable(...hintInfo: unknown[]): string {
    let msg = '';

    if (__DEV__) {
        // Fuzzy stringify for print.
        // This code only exist in dev environment.
        const makePrintableStringIfPossible = (val: unknown): string => {
            return val === void 0 ? 'undefined'
                : val === Infinity ? 'Infinity'
                : val === -Infinity ? '-Infinity'
                : eqNaN(val) ? 'NaN'
                : val instanceof Date ? 'Date(' + val.toISOString() + ')'
                : isFunction(val) ? 'function () { ... }'
                : isRegExp(val) ? val + ''
                : null;
        };
        msg = map(hintInfo, arg => {
            if (isString(arg)) {
                // Print without quotation mark for some statement.
                return arg;
            }
            else {
                const printableStr = makePrintableStringIfPossible(arg);
                if (printableStr != null) {
                    return printableStr;
                }
                else if (typeof JSON !== 'undefined' && JSON.stringify) {
                    try {
                        return JSON.stringify(arg, function (n, val) {
                            const printableStr = makePrintableStringIfPossible(val);
                            return printableStr == null ? val : printableStr;
                        });
                        // In most cases the info object is small, so do not line break.
                    }
                    catch (err) {
                        return '?';
                    }
                }
                else {
                    return '?';
                }
            }
        }).join(' ');
    }

    return msg;
}

/**
 * @throws Error