Deploy with Manifests from URLs (#251)

* added functionality, need to add/modify existing tests

* added tests

* updated readme

* prettier

src/types/errorable.ts

@@ -0,0 +1,48 @@
+export interface Succeeded<T> {
+   readonly succeeded: true
+   readonly result: T
+}
+
+export interface Failed {
+   readonly succeeded: false
+   readonly error: string
+}
+
+export type Errorable<T> = Succeeded<T> | Failed
+
+export function succeeded<T>(e: Errorable<T>): e is Succeeded<T> {
+   return e.succeeded
+}
+
+export function failed<T>(e: Errorable<T>): e is Failed {
+   return !e.succeeded
+}
+
+export function map<T, U>(e: Errorable<T>, fn: (t: T) => U): Errorable<U> {
+   if (failed(e)) {
+      return {succeeded: false, error: e.error}
+   }
+   return {succeeded: true, result: fn(e.result)}
+}
+
+export function combine<T>(es: Errorable<T>[]): Errorable<T[]> {
+   const failures = es.filter(failed)
+   if (failures.length > 0) {
+      return {
+         succeeded: false,
+         error: failures.map((f) => f.error).join('\n')
+      }
+   }
+
+   return {
+      succeeded: true,
+      result: es.map((e) => (e as Succeeded<T>).result)
+   }
+}
+
+export function getErrorMessage(error: unknown) {
+   if (error instanceof Error) {
+      return error.message
+   }
+   return String(error)
+}