Create Dependency

new utility types for optionalizing dependencies

Author: NielsJPeschel

types/Dependency

@@ -0,0 +1,66 @@
+export interface DependencyBase<T> {
+  isInProgress: boolean;
+  isError: boolean;
+  error?: unknown;
+  result?: T | null;
+  optional?: boolean;
+}
+export interface PendingOptionalDependency<T> extends DependencyBase<T> {
+  isInProgress: true;
+  isError: false;
+  error: undefined;
+  result: undefined;
+  optional: true;
+}
+
+export interface SuccessfulOptionalDependency<T> extends DependencyBase<T> {
+  isInProgress: false;
+  isError: false;
+  error: undefined;
+  result: T | null;
+  optional: true;
+}
+
+export interface FailedOptionalDependency<T> extends DependencyBase<T> {
+  isInProgress: false;
+  isError: true;
+  error: unknown;
+  result: undefined;
+  optional: true;
+}
+
+export type OptionalDependency<T = unknown> =
+  | PendingOptionalDependency<T>
+  | SuccessfulOptionalDependency<T>
+  | FailedOptionalDependency<T>;
+
+export interface PendingRequiredDependency<T> extends DependencyBase<T> {
+  isInProgress: true;
+  isError: false;
+  error: undefined;
+  result: undefined;
+  optional?: false;
+}
+
+export interface SuccessfulRequiredDependency<T> extends DependencyBase<T> {
+  isInProgress: false;
+  isError: false;
+  error: undefined;
+  result: T;
+  optional?: false;
+}
+
+export interface FailedRequiredDependency<T> extends DependencyBase<T> {
+  isInProgress: false;
+  isError: true;
+  error: unknown;
+  result: undefined;
+  optional?: false;
+}
+
+export type RequiredDependency<T = unknown> =
+  | PendingRequiredDependency<T>
+  | SuccessfulRequiredDependency<T>
+  | FailedRequiredDependency<T>;
+
+export type Dependency<T = unknown> = OptionalDependency<T> | RequiredDependency<T>;