Apollo-ios: Creating Query.Data manually for testing

[jeffgilbert]

Hi,

I want to write some unit tests around processing query results. Let's say I have this query:

query userName($userID: ID!)
{
  user(id: $userID)
  {
    firstName
    lastName
  }
}

In the Swift code, after I fetch the query from the client, I'll end up with GraphQLResult<UserNameQuery.Data>.

For my tests, is there a way I can start with a string representation of the result JSON, e.g.

{
  "data": {
    "user": {
      "firstName": "John",
      "lastName": "Doe"
    }
  }
}

and create a UserNameQuery.Data object that I can pass to my code that processes the result?

I've tried different initializers but they don't seem to fully populate the object.

Thanks,
Jeff

[designatednerd]

You should be able to use the public init(unsafeResultMap: ResultMap) initializer that's included with the Data objects. ResultMap is just a typealias to a [String: Any?] dictionary.

[jeffgilbert]

Thanks so much! Works like a charm. You just saved me a ton of time vs testing things manually.

[designatednerd]

Huzzah! Mind if we close this issue out then?

[jeffgilbert]

Not at all. I'll close it.

[jeffgilbert]

As an addendum, I have a query that contains an enum. Is there a way I can have the JSON text parsed from a string to the proper enum? When I init my Data object using unsafeResultMap (from my test) the string (correctly) stays as a string. e.g.

{
  "user": {
    "__typename": "User",
    "status": "UNSELECTED",
  }
}

status is an enum with cases for selected, and unselected.

When my parser test tries to parse the data, it fails because the value for the key is a string, not an enum.

Is there a mechanism I can invoke to parse any strings into enums when building up my Data object?

Thanks,
Jeff

[designatednerd]

Can you send what the generated getter for status looks like? In theory since that type should be generated as a string-based enum, you should be able to just use the failable initializer for the type to do the conversion.

[jeffgilbert]

Of course.

        public var status: UserStatus {
          get {
            return resultMap["status"]! as! UserStatus
          }
          set {
            resultMap.updateValue(newValue, forKey: "status")
          }
        }

[jeffgilbert]

PS This is how I create my Data object in my test.

        let data = UserQuery.Data(unsafeResultMap: json(
        """
        {
          "user": {
            "__typename": "User",
            "status": "UNSELECTED"
          }
        }
        """))

json is a simple function that turns a String into a ResultMap. I'm copying the text from GrqphiQL to match what I'll receive from my backend.

[designatednerd]

You should be able to just use a dictionary since UnsafeResultMap is just a typealias to a dictionary - so something like

let data = UserQuery.Data(unsafeResultMap: [
  "user": [
     "__typename": "User", 
     "status": .unselected
  ]
])

[jeffgilbert]

Thanks. That works. Digging into it more it looks like it would be rather difficult to create the Data object from a json string. Converting the string to a Swift dictionary literal isn't that much work—just convert {} to [] :-)

[jigneshD11]

@designatednerd is there a way in which i can parse jsonstring into GraphqQLResponse object specially when you are using custom scalar type? Current parseResult function is not public.