Function checkJson

test/utils.ts:151–237

(
  inExpr: ExpressionInput | null,
  variants?: Array<ExprVariant>
)

  inExpr: ExpressionInput | null,
  variants?: Array<ExprVariant>
): string {
  if (!inExpr) return 'null';
  const ce =
    inExpr instanceof _BoxedExpression
      ? inExpr.engine
      : engine; /* default test engine */
  const precision = ce.precision;
  try {
    ce.precision = 'auto';

    variants ??= [
      'box',
      'canonical',
      'simplify',
      'eval-auto',
      'eval-mach',
      'N-mach',
      'N-auto',
    ];

    const boxed = exprToString(ce.expr(inExpr, { form: 'raw' }));

    const expr = ce.expr(inExpr);

    if (!expr.isValid) return `invalid   =${exprToString(expr)}`;

    const canonical = exprToString(expr);

    const simplifyExpr = expr.simplify();
    const simplify = simplifyExpr.toString();
    const evalAuto = expr.evaluate().toString();
    const numEvalAuto = expr.N().toString();

    ce.precision = 'machine';
    // Re-box at machine precision so internal NumericValue representations
    // use MachineNumericValue, not BigNumericValue from the higher-precision parse
    const machExpr = ce.expr(expr.json);
    const evalMachine = machExpr.evaluate().toString();
    const numEvalMachine = machExpr.N().toString();

    if (
      boxed === canonical &&
      simplifyExpr.isSame(expr) &&
      evalAuto === simplify &&
      evalAuto === evalMachine &&
      evalAuto === numEvalAuto &&
      evalAuto === numEvalMachine
    ) {
      return boxed;
    }

    const result: string[] = [];
    if (variants.includes('box')) result.push('box       = ' + boxed);

    if (canonical !== boxed && variants.includes('canonical'))
      result.push('canonical = ' + canonical);

    if (simplify !== expr.toString() && variants.includes('simplify'))