conditional-display.js

const {
    str,
    char,
    digits,
    letters,
    sequenceOf,
    anythingExcept,
    anyOfString,
    many,
    choice,
    optionalWhitespace,
    between,
} = require('arcsecond');


const trueValue = str('true').map(() => true);

const falseValue = str('false').map(() => false);

const delimiter = anyOfString(`"'\``);

const stringValue = between(delimiter) (delimiter) (
        many(anythingExcept(delimiter))
    ).map(arr => arr.join(''));

const numberValue = digits.map(Number);

const access = sequenceOf([char('.'), letters]).map(([,tail]) => tail);

const propertyValue = sequenceOf([
    letters,
    many(access),
]).map(([name, accesses]) => [name, ...accesses]);

const value = choice([
    trueValue,
    falseValue,
    numberValue,
    stringValue,
    propertyValue,
]);

const equalityOperator = choice([
    str('=='),
    str('!='),
]);

const zipWhitespace = (arr) => arr.map((p) =>
    sequenceOf([optionalWhitespace, p, optionalWhitespace])
        .map(([,tail]) => tail)
);

const equality = sequenceOf(zipWhitespace([
    value,
    equalityOperator,
    value,
]));


console.log(equality.run('true == false').result)
[ true, '==', false ]

console.log(equality.run('true == 3').result)
[ true, '==', 3 ]

console.log(equality.run(" 'test123'==3 ").result)
[ 'test123', '==', 3 ]

console.log(equality.run('this.object.name == "hello" ').result)
[ [ 'this', 'object', 'name' ], '==', 'hello' ]

console.log(equality.run("window == false ").result)
[ [ 'window' ], '==', false ]