如何在量角器测试中使用lodash _.find？

Question

I want to use the Lodash find function to make my Protractor tests more robust.

Instead of

    element.all (by.repeater ('topic in topics')).then (function (topics) {

        expect (topics[1].element (by.binding ('topic.name')).getText()).toEqual ('Maths');
        expect (topics[1].element (by.binding ('topic.description')).getText()).toEqual ('2 + 2 = 4');  
    });

Something like

    element.all (by.repeater ('topic in topics')).then (function (topics) {

        var mathsTopic = _.find (topics, 'topic.name', 'Maths');
        expect (mathsTopic.element (by.binding ('topic.description')).getText()).toEqual ('2 + 2 = 4');    
    });

My reasoning is so that, if the order of items in the page changes, the test does not break as it can still find the element with the data it is looking for.

Answer 1

You almost got it:

var mathsTopic = _.find(topics, { name: 'Maths' });

Which can be read as: Find me the first topic in topics that has a name property which equals 'Maths'.

Answer 2

Did you try using filter ?

var topic = element.all(by.repeater('topic in topics'))
    .filter(function (row) {
      return row.element(by.binding('topic.name')).getText().then(function(name) {
        return name === 'Maths';
      });
    })
   .first()
   .map(function(row) {
     return {
       name: row.element(by.binding('topic.name')).getText()),
       description: row.element(by.binding('topic.description')).getText())
     };
   });

expect(topic).toEqual({
  name: 'Maths',
  description: '2 + 2 = 4'
});