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Possibly Read As Nullable

This page discusses how to use PossiblyReadAsNullable and AllNodesPossiblyReadAsNullable.

PossiblyReadAsNullable​

This section discusses how to use PossiblyReadAsNullable

info

PossiblyReadAsNullable unions nodes read type with null and undefined.

Type Checks​

import {
    MetaTypeCreator,
    ServerTimestamp,
    NumericKeyRecord,
    PossiblyReadAsNullable,
    createRef,
    getDatabase,
    get,
    PushAble,
    PushAbleOnly,
} from 'firesagejs'

export type Example = MetaTypeCreator<{
    a: number | PossiblyReadAsNullable
    b: number
}>
const exampleRef = createRef<Example>(getDatabase())

get(exampleRef()).then(dataSnapshot => {
    // type of data is { a: number | null | undefined; b: number} | null
    // PossiblyReadAsNullable union node read type with null and undefined
    const data = dataSnapshot.val()
})

// you can union `PossiblyReadAsNullable` to any node
export type Example2 = MetaTypeCreator<
    | {
            b:
                | {
                        c: boolean | PossiblyReadAsNullable
                        d:
                            | {
                                    e: ServerTimestamp | PossiblyReadAsNullable
                              }
                            | PossiblyReadAsNullable
                  }
                | PossiblyReadAsNullable
            f:
                | Record<string, 'a' | 'b' | 'c' | PossiblyReadAsNullable>
                | PossiblyReadAsNullable
            i:
                | NumericKeyRecord<boolean | PossiblyReadAsNullable>
                | PossiblyReadAsNullable
            j:
                | PushAble<1 | 2 | 3 | 4 | PossiblyReadAsNullable>
                | PossiblyReadAsNullable
            k:
                | PushAbleOnly<
                        | { l: ServerTimestamp | PossiblyReadAsNullable }
                        | PossiblyReadAsNullable
                  >
                | PossiblyReadAsNullable
      }
    | PossiblyReadAsNullable
>
how to use PossiblyReadAsNullable

AllNodesPossiblyReadAsNullable​

This section discusses how to use AllNodesPossiblyReadAsNullable.

Type Checks​

info

AllNodesPossiblyReadAsNullable is not a type but a setting, it unions null and undefined to all nodes read type.

import {
    MetaTypeCreator,
    ServerTimestamp,
    NumericKeyRecord,
    createRef,
    getDatabase,
    get,
    PushAble,
    PushAbleOnly,
} from 'firesagejs'

export type Example = MetaTypeCreator<
    {
        b: {
            c: boolean
            d: {
                e: ServerTimestamp
            }
        }
        f: Record<string, 'a' | 'b' | 'c'>
        i: NumericKeyRecord<boolean>
        j: PushAble<1 | 2 | 3 | 4>
        k: PushAbleOnly<{ l: ServerTimestamp }>
    },
    { AllNodesPossiblyReadAsNullable: true }
>

const exampleRef = createRef<Example>(getDatabase())

get(exampleRef()).then(dataSnapshot => {
    // AllNodesPossiblyReadAsNullable union all nodes read type with null and undefined
    const data = dataSnapshot.val()
})
how to use AllNodesPossiblyReadAsNullable