RangeError for combination of recursive input and default value #3871
Description
Hi, I was working with input fields' default values in graphql-core and I encountered a problem with a combination of recursive inputs and default values which also occurs in graphql-js.
Let's take this SDL as an example:
"""Example 1"""
type Query { field(recursiveInput: RecursiveInput): String }
input RecursiveInput {
self: RecursiveInput = {value: "foo"}
value: String
}If I understand correctly that example is invalid, because {value: "foo"} is lacking the self field, then the default value for self is looked up, which leads to a recursion error - RangeError: Maximum call stack size exceeded.
When the default value is removed, everything works fine:
"""Example 2"""
type Query { field(recursiveInput: RecursiveInput): String }
input RecursiveInput {
self: RecursiveInput
value: String
}However, the following also looks fine, because self doesn't need to be looked up, but it still causes a recursion error:
"""Example 3"""
type Query { field(recursiveInput: RecursiveInput): String }
input RecursiveInput {
self: RecursiveInput = {value: "foo", self: null}
value: String
}On the other hand, the following actually invalid example does not give an error:
"""Example 4"""
type Query { field(recursiveInput: RecursiveInput): String }
input RecursiveInput {
self: RecursiveInput!
value: String
}If I'm not mistaken:
- Example 1 should produce a proper error instead of creating a stack overflow
- Example 3 should not produce an error
- Example 4 should produce an error showing that this is an invalid definition
To test all examples I used graphql@16.6.0 and following code:
const { buildSchema } = require('graphql');
const schemaString = `...`;
const schema = buildSchema(schemaString);