Métodos trim e toLowerCase não funcionam

Tenho o código abaixo, idêntico ao da aula, porém não funciona

import { Pipe, PipeTransform } from "@angular/core";
import { Photo } from "../photo/photo";

@Pipe({
    name: 'filterByDescription'
})
export class FilterByDescription implements PipeTransform {

    transform(photos: Photo[], descriptionQuery: string) {
        descriptionQuery = descriptionQuery
            .trim()
            .toLowerCase();

        if(descriptionQuery) {
            return photos.filter(photo => 
                photo.description.toLowerCase().includes(descriptionQuery));
        } else {
            return photos;
        }

    }

}

Stack do erro

PhotoListComponent.html:12 ERROR TypeError: Cannot read property 'trim' of undefined
    at FilterByDescription.push../src/app/photos/photo-list/filter-by-description.pipe.ts.FilterByDescription.transform (filter-by-description.pipe.ts:11)
    at checkAndUpdatePureExpressionInline (core.js:9942)
    at checkAndUpdateNodeInline (core.js:10511)
    at checkAndUpdateNode (core.js:10469)
    at debugCheckAndUpdateNode (core.js:11102)
    at debugCheckDirectivesFn (core.js:11062)
    at Object.eval [as updateDirectives] (PhotoListComponent.html:12)
    at Object.debugUpdateDirectives [as updateDirectives] (core.js:11054)
    at checkAndUpdateView (core.js:10451)
    at callViewAction (core.js:10692)