Javascript hasOwnProperty(key) === false 但属性存在

Question

I have an object called context and these logs:

console.log({
  context,
  "Object.keys(context)": Object.keys(context),
  'context.hasOwnProperty("status")': context.hasOwnProperty("status"),
  "context.status": context.status,
});

Here's the output:

context
  cache: InMemoryCache
  client: ApolloClient
  clientAwareness {...}
  forceFetch: false
  getCacheKey: f()
  status: 3
Object.keys(context): Array(5)
  0: "forceFetch"
  1: "cache"
  2: "getCacheKey"
  3: "clientAwareness"
  4: "client"
context.hasOwnProperty("status"): false
context.status: undefined

How can it possibly be that the status property is defined and has a value of 3, but "Object.keys", "hasOwnProperty" and accessing it indicate that it doesn't exist?

Update

Here's a CodeSandbox with my code. If you open ./apollo/resolvers/bar , you'll see the logs for the context object.

Update 2

I found out what was going on. The order of the fields in my GraphQL query was not correct, in that the resolver that was logging the context was defined before the resolver for status . See my answer below.

Answer 1

It turns out the issue was caused by a weird behaviour of Apollo.

In my GraphQL query, I defined status below the resolver where I was logging the values of context :

query Foo {
  id
  bar @client
  status @client
}

Moving status to the top fixes the issue:

query Foo {
  id
  status @client
  bar @client
}

Answer 2

Make sure your property is enumerable. Respond with more code where you are creating this object [See here][1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Enumerability_and_ownership_of_properties