Why does having categories as a field name errors out?

I have the query below with categories as the field name

right now i renamed it to test and it works fine

but doing so with categories

would throw an error that it's undefined

why?

apollo: {
    plant: {
      query: gql`
        query Plant($id: ID) {
          plant(id: $id) @client {
            id
            commonName
            scientificName
            maxHeight
            nativeTo
            growingArea
            growingRate
            sunlightRequirement
            waterRequirement
            prices {
              id
              gallon
              size
              price
            }
            test: categories {
              id
              name
            }
          }
        }
      `,
      variables() {
        return {
          id: this.id
        }
      }
    }
  }

Start by reproducing the Apollo query shown in the issue, comparing the direct categories field with the test: categories alias. Trace how the client handles the categories selection and capture the resulting error; done means identifying the cause and documenting or correcting the behavior, with a regression test if the repository provides a relevant test entry point.