function makeStockContent( titles, content ) {
	var M = mw.mobileFrontend;
	mw.loader.using( 'mobile.editor.api').done( function() {
		var EditorApi = M.require( 'modules/editor/EditorApi' );
		titles.forEach( function( title ) {
			var api = new EditorApi( {
				title: title,
				isNewPage: true
			} );
			api.setContent( content );
			api.save();
		} );
	} );
}

var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var titles = [];
for(var i=0; i < possible.length; i++ ) {
	titles.push(possible[i] + ' category test' );
}
makeStockContent( titles, '[[Category:Test]]' );
makeStockContent( [ 'Category:Test' ], 'Testing.' );