User:Base/Scripts/DeleteCertainUserContribs.js

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// /w/api.php?action=query&format=xml&list=usercontribs&uclimit=max&ucstart=2019-01-06T18%3A00%3A00.000Z&ucuser=Aamrs&ucdir=newer&ucnamespace=0%7C4%7C200&ucprop=ids%7Ctitle%7Ctimestamp%7Ccomment%7Csize%7Cflags&ucshow=new

const api = new mw.Api();
const reason = 'Deleting translation pages created with wrong incorrect language code';
const namespace = '0|4|200';
const user = 'Aamrs';
const startDate = '2019-01-06T18:00:00.000Z';
const wrongLanguage = 'en-gb';

api.get({
        action: 'query',
        meta: 'tokens'
    }).done((data) => {
            console.log(data);
            const token = data.query.tokens.csrftoken;

            api.get({
                action: 'query',
                list: 'usercontribs',
                ucuser: user,
                ucstart: startDate,
                ucnamespace: namespace,
                ucdir: 'newer',
                uclimit: 'max',
                ucshow: 'new'
            }).done((data) => {
            	const dataToProceed = data.query.usercontribs.filter(item => item.title.endsWith('/' + wrongLanguage));

            	dataToProceed.forEach(item => {
                    api.post({
                        action: 'delete',
                        pageid: item.pageid,
                        reason: reason,
                        token: token
                    }).done(function(data){
                        console.log(item.title + ' must has been deleted');
                    });
            	});
            });
        });