import { coreAST, print, builders } from './core';

test('pretty-printer', () => {
  expect(print(coreAST)).toEqual(`
Grammar = Rule ++ ";"
Rule = identifier "=" AltExpr
AltExpr = SeqExpr ++ "|"
SeqExpr = SepExpr+ (":" value)?
SepExpr = RepExpr "**" RepExpr
        | RepExpr "++" RepExpr
        | RepExpr
RepExpr = Expr "*"
        | Expr "+"
        | Expr "?"
        | Expr
Expr = #( AltExpr )
     | "#" #( AltExpr )
     | "#" #[ AltExpr ]
     | "#" #{ AltExpr }
     | "include" value
     | identifier
     | "identifier"
     | "operator"
     | "keyword"
     | "value"
     | "nil"
     | value`);

  const { error, repeat0, sepBy0, lit, seq, alt } = builders;

  const grammarWithOtherTokens = repeat0(sepBy0(error('message'), lit('foo')));
  expect(print(grammarWithOtherTokens)).toEqual(`(<error: message> ** "foo")*`);

  const grammarWithInnerAlt = seq(
    () => null,
    alt(lit('foo'), lit('bar')),
    lit('baz')
  );
  expect(print(grammarWithInnerAlt)).toEqual(`("foo" | "bar") "baz"`);

  const grammarWithEmptySeq = seq(() => null);
  expect(print(grammarWithEmptySeq)).toEqual(`nil`);
});