UpdateExpression.js
797 Bytes
/**
* Extractor function for an UpdateExpression type value node.
* An update expression is an expression with an update operator.
* For example, foo++ will evaluate to foo + 1.
*
* @param - value - AST Value object with type `UpdateExpression`
* @returns - The extracted value converted to correct type.
*/
export default function extractValueFromUpdateExpression(value) {
// eslint-disable-next-line global-require
const getValue = require('./index.js').default;
const { operator, argument, prefix } = value;
let val = getValue(argument);
switch (operator) {
case '++':
return prefix ? ++val : val++; // eslint-disable-line no-plusplus
case '--':
return prefix ? --val : val--; // eslint-disable-line no-plusplus
default:
return undefined;
}
}