Function injectMutation

packages/angular-query-experimental/src/inject-mutation.ts:174–328

(
  injectMutationFn: () => CreateMutationOptions<
    TData,
    TError,
    TVariables,
    TOnMutateResult
  >,
  options?: InjectMutationOptions,
)

 * ```
 */
export function injectMutation<
  TData = unknown,
  TError = DefaultError,
  TVariables = void,
  TOnMutateResult = unknown,
>(
  injectMutationFn: () => CreateMutationOptions<
    TData,
    TError,
    TVariables,
    TOnMutateResult
  >,
  options?: InjectMutationOptions,
): CreateMutationResult<TData, TError, TVariables, TOnMutateResult> {
  !options?.injector && assertInInjectionContext(injectMutation)
  const injector = options?.injector ?? inject(Injector)
  const ngZone = injector.get(NgZone)
  const pendingTasks = injector.get(PENDING_TASKS)
  const queryClient = injector.get(QueryClient)

  /**
   * computed() is used so signals can be inserted into the options
   * making it reactive. Wrapping options in a function ensures embedded expressions
   * are preserved and can keep being applied after signal changes
   */
  const optionsSignal = computed(injectMutationFn)

  const observerSignal = (() => {
    let instance: MutationObserver<
      TData,
      TError,
      TVariables,
      TOnMutateResult
    > | null = null

    return computed(() => {
      return (instance ||= new MutationObserver(queryClient, optionsSignal()))
    })
  })()

  const mutateFnSignal = computed<
    CreateMutateFunction<TData, TError, TVariables, TOnMutateResult>
  >(() => {
    const observer = observerSignal()
    return (
      ...args: Parameters<
        CreateMutateFunction<TData, TError, TVariables, TOnMutateResult>
      >
    ) => {
      observer.mutate(args[0] as TVariables, args[1]).catch(noop)
    }
  })

  /**
   * Computed signal that gets result from mutation cache based on passed options
   */
  const resultFromInitialOptionsSignal = computed(() => {
    const observer = observerSignal()