Currying in the real world

curryingInTheRealWorld.js

parseAttachements: (item, baseUrl, images, documents) => {
        images = images || [];
        documents = documents || []; 

        return _.mapValues(item, (v, k) => {
            const parse = baseUrl => type => (attachement, size) => 
                            self.attachementUrl(baseUrl, type, attachement, size);
            const parsePreview = parse(baseUrl)('preview');
            const parseStatic = parse(baseUrl)('static');

             if(images.indexOf(k) != -1 && k === 'highResImage' && v) { 
                 return parsePreview(v, 1800) 
                } ;
                
            if(images.indexOf(k) != -1) {
                if(_.isArray(v) ) {
                    return  _.map(v, c => { 
                            if(c.image) {  
                                c.image = parsePreview(c.image, 500);
                            }       
                            return c;
                    }); 
                }
                if(k !== 'highResImage') { return parsePreview(v, 500); }
            }

            if(documents.indexOf(k) != -1 && v) {
                return parseStatic(v);
            }

            //make sure to return false for those properties that were untouched
            if(documents.indexOf(k) != -1 || images.indexOf(k) != -1)
            { return false; }

            //make sure to return all other values untouched
            return v;
        });
    }