decaffeinate-parser/dist/mappers/mapIf.mjs

A better AST for CoffeeScript, inspired by CoffeeScriptRedux.

import { SourceType } from 'coffee-lex';
import { Conditional } from '../nodes';
import getLocation from '../util/getLocation';
import mapAny from './mapAny';
import mapPossiblyEmptyBlock from './mapPossiblyEmptyBlock';
export default function mapIf(context, node) {
    var _a = getLocation(context, node), line = _a.line, column = _a.column, start = _a.start, end = _a.end, raw = _a.raw;
    var condition = mapAny(context, node.condition);
    var consequent = mapPossiblyEmptyBlock(context, node.body);
    var alternate = mapPossiblyEmptyBlock(context, node.elseBody);
    var isUnless = false;
    var left = null;
    var right = null;
    if (consequent && consequent.start < condition.start) {
        consequent = consequent.withInline(true);
        // POST-if, so look for tokens between the consequent and the condition
        left = context.sourceTokens.indexOfTokenEndingAtSourceIndex(consequent.end);
        right = context.sourceTokens.indexOfTokenStartingAtSourceIndex(condition.start);
    }
    else {
        // regular `if`, so look from the start of the node until the condition
        left = context.sourceTokens.indexOfTokenStartingAtSourceIndex(start);
        right = context.sourceTokens.indexOfTokenStartingAtSourceIndex(condition.start);
    }
    if (left && right) {
        isUnless =
            context.sourceTokens.indexOfTokenMatchingPredicate(function (token) {
                return token.type === SourceType.IF &&
                    context.source.slice(token.start, token.end) === 'unless';
            }, left, right) !== null;
    }
    return new Conditional(line, column, start, end, raw, condition, consequent, alternate, isUnless);
}