Allow access to parent schema (and unlimited ancestors!) in test context

[akmjenkins]

I made a terrible attempt at this PR earlier. This should do it.

This resolves #551 and adds the capability to help with #553.

[akmjenkins]

I've updated this PR, hope you don't mind. I know accessing multiple ancestors has been an issue people have been trying to solve around here and I thought that this PR could be easily expanded to solve it. Ideally, the existing parent property in the test context would be a function, but in the interest of not making a breaking change, I've added a from in the test context that returns the parent value, the parent schema and, if applicable, another from method which can be used to access unlimited ancestors like so:

  test: function() {
     // get the parent schema, value, and another from, if applicable
     const { schema, value, from } = this.from(); 

     // get an ancestor a long way back
     const wayBackAncestor = this.from().from().from().from()....
  }

This should make work regarding #201 a breeze.

[akmjenkins]

Thought I'd add a newer comment to override my older one. The most up to date proposal is for accessing parent(s) and parent schema(s) in a test context is to look like this:

  test() {
     const { value: parent, schema: parentSchema } = this.from[0];
     const { value: grandparent, schema: grandparentSchema } = this.from[1];
     ....
     const { value: gggggggrandparent, schema: gggggggrandparentSchema } = this.from[7]
  }

[BenevidesLecontes]

@jquense we need this desperately.

[jquense]

sorry the delay folks, short on time!

[jquense]

splice returns the removed item not the array, is that what you want here?

[akmjenkins]

No, it's not what I wanted to do, thanks for the catch. I've updated this.

[jquense]

what happens if you have an array inbetween?

[akmjenkins]

what happens if you have an array inbetween?

I've added a modified the test case to showcase this, but in doing so I don't like what I've done. I'm still missing something in how refs are resolved. I made some comments in my test, @jquense hope you could offer me some suggestions?

[yanzou]

@akmjenkins any update on this?
it would be a great help for me if this get merged!

it takes me 3+ misrable days googleing/check issues/the Yup source code and realize it is not possible to get values from ancestors...

[HansAarneLiblik]

This could really use documentation and this is missing from @types/yup

[ghost]

i need documenation for this

[geocine]

For anyone wondering how this could be used this is how.

  const schema = Yup.object().shape({
    origin: Yup.object().shape({
      location: Yup.string().required(),
      port: Yup.string()
        .nullable()
        .test('customValidation', 'Error', function(val) {
          const { parent, from } = this;
          
          // Before we can only access the immediate parent values
          // of this property which is `origin` so we can get `parent.location`

          // But what if we want to get `destintation.location` , with parent, this is not possible
          // now we can, using, `from[1].value.destination.location` for getting the value 
        })
    }),
    destination: Yup.object().shape({
      location: Yup.string().required(),
      port: Yup.string().required()
    })
  });

From the context of origin.port above. If you need n levels up just use from[n] where n is the number of levels starting from 0

So getting back at the example above parent.location will be the same as from[0].value.location

Aside from values, this also introduced a way of getting the schema now you can get the schema at different levels using from[n].schema.

[akmjenkins]

For anyone wondering how this could be used this is how.

  const schema = Yup.object().shape({
    origin: Yup.object().shape({
      location: Yup.string().required(),
      port: Yup.string()
        .nullable()
        .test('customValidation', 'Error', function(val) {
          const { parent, from } = this;
          
          // Before we can only access the immediate parent values
          // of this property which is `origin` so we can get `parent.location`

          // But what if we want to get `destintation.location` , with parent, this is not possible
          // now we can, using, `from[1].value.location` for getting the value 
        })
    }),
    destination: Yup.object().shape({
      location: Yup.string().required(),
      port: Yup.string().required()
    })
  });

From the context of origin.port above. If you need n levels up just use from[n] where n is the number of levels starting from 0

So getting back at the example above parent.location will be the same as from[0].value.location

Aside from values, this also introduced a way of getting the schema now you can get the schema at different levels using from[n].schema.

If you wanted to get destination.location you'd use from[1].value.destination.location.

Also, I was hoping this would make it relatively trivial to implement relative references, but using toposort to sort the graph has made things a little more complicated for me in this regard, hoping to get to it soon.

[geocine]

If you wanted to get destination.location you'd use from[1].value.destination.location.

Oh yeah right I will correct that. Thanks for this @akmjenkins

[zelucena]

I have just come across this issue. I upgraded Yup in my project from version 0.28.1 to 0.29.1
const { parent, from } = this; const grandParent = from[1].value;
It works just fine.

[lucksp]

Are the typescript Types updated? I do not see anything with from declared, so I am having to do some nasty casting...

[adaladam]

awesome work guys, thank you!

[singlapradeep27]

will it work for when too?

[adjenks]

This still isn't in the docs.

[adjenks]

will it work for when too?

You can try stuffing the values object into the context parameter during validation, then accessing the values with the "$" context prefix. This worked for me, but it seems to have some limitations of its own.

[BenJackGill]

Why is this not documented? It's very useful!