Merge pull request #2 from yajamon/feature/unwrap

unwrap()の追加

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@yajamon/result.ts",
-  "version": "0.1.1",
+  "version": "0.2.0",
   "description": "Type definitions and simple functions inspired by Rust's Result.",
   "main": "lib/main.js",
   "scripts": {

src/main.test.ts

@@ -1,4 +1,4 @@
-import { Err, Ok, Result } from "./main";
+import { Err, Ok, Result, unwrap } from "./main";
 
 describe("Ok", () => {
   it("is return ResultOk", () => {
@@ -23,3 +23,16 @@ describe("Err", () => {
     }
   });
 });
+
+describe("unwrap()", () => {
+  it("throw when ResultErr", () => {
+    expect(() => {
+      unwrap(Err("error"));
+    }).toThrow("error");
+  });
+
+  it("return value when ResultOk", () => {
+    const ok = Ok("success");
+    expect(unwrap(ok)).toBe("success");
+  });
+});

src/main.ts

@@ -18,3 +18,10 @@ export const Err: <E>(error: E) => ResultErr<E> = e => ({
   isError: true,
   error: e
 });
+
+export const unwrap: <T, E>(result: Result<T, E>) => T = result => {
+  if (result.isError) {
+    throw result.error;
+  }
+  return result.value;
+};