feat(Promise): added tryOneByOne

Author: alisahinozcelik

README.md

@@ -340,6 +340,23 @@ const promise = anAsyncCall();
 const [error, result] = await tryCatch(promise);
 ```
 
+#### [Try One By One](https://thalesrc.github.io/js-utils/modules/_promise_try_one_by_one_.html)
+Tries a set of promises one by one with given order. Breaks the call when a promise resolved. Otherwise keeps trying incoming promises until the list is finished.
+
+```typescript
+import { tryOneByOne } from "@thalesrc/js-utils/promise";
+
+async function fooFunction() {
+  const foo = await tryOneByOne([
+    () => someCall(),
+    (err) => anotherCall(),
+    (err) => fooPromise()
+  ]);
+
+  // do stuff
+}
+```
+
 ### String
 
 #### [Limit](https://thalesrc.github.io/js-utils/modules/_string_limit_.html)

src/promise/index.ts

@@ -1,4 +1,5 @@
 export * from './never';
 export * from './revert';
 export * from './try-catch';
+export * from './try-one-by-one';
 export * from './timeout';

src/promise/static/try-one-by-one.ts

@@ -0,0 +1,30 @@
+import { tryOneByOne } from '../try-one-by-one';
+
+declare global {
+  export interface PromiseConstructor {
+    /**
+     * #### Try One By One
+     * Tries a set of promises one by one with given order. Breaks the call when a promise resolved. Otherwise keeps trying incoming promises until the list is finished.
+     *
+     * * * *
+     * Example:
+     * ```typescript
+     * import "@thalesrc/js-utils/promise/static/try-one-by-one";
+     *
+     * async function fooFunction() {
+     *   const foo = await Promise.tryOneByOne([
+     *     () => someCall(),
+     *     (err) => anotherCall(),
+     *     (err) => fooPromise()
+     *   ]);
+     *
+     *   // do stuff
+     * }
+     * ```
+     * * * *
+     */
+    tryOneByOne: typeof tryOneByOne;
+  }
+}
+
+Promise.tryOneByOne = tryOneByOne;

src/promise/try-one-by-one.spec.ts

@@ -0,0 +1,34 @@
+import 'jest';
+
+import { tryOneByOne } from './try-one-by-one';
+
+class CustomError {
+  constructor(public message: string) {}
+}
+
+describe('TryOneByOne Function', () => {
+  it('should resolve if a promise resolved', done => {
+    tryOneByOne([Promise.resolve('foo')])
+      .then(res => {
+        expect(res).toBe('foo');
+        done();
+      })
+      .catch(err => {
+        throw new CustomError("didn't resolve");
+      });
+  });
+
+  it('should try the next promise when the first threw error', done => {
+    tryOneByOne([
+      Promise.reject('foo'),
+      Promise.resolve('bar'),
+    ])
+      .then(res => {
+        expect(res).toBe('bar');
+        done();
+      })
+      .catch(err => {
+        throw new CustomError("didn't resolve");
+      });
+  });
+});

src/promise/try-one-by-one.ts

@@ -0,0 +1,58 @@
+/**
+ * #### Try One By One
+ *
+ * Tries a set of promises one by one with given order. Breaks the call when a promise resolved. Otherwise keeps trying incoming promises until the list is finished.
+ *
+ * * * *
+ * Example:
+ * ```typescript
+ * import { tryOneByOne } from "@thalesrc/js-utils/promise";
+ *
+ * async function fooFunction() {
+ *   const foo = await tryOneByOne([
+ *     () => someCall(),
+ *     (err) => anotherCall(),
+ *     (err) => fooPromise()
+ *   ]);
+ *
+ *   // do stuff
+ * }
+ *
+ * ```
+ *
+ * Static Example:
+ * ```typescript
+ * import "@thalesrc/js-utils/promise/static/try-one-by-one";
+ *
+ * async function fooFunction() {
+ *   const foo = await Promise.tryOneByOne([
+ *     () => someCall(),
+ *     (err) => anotherCall(),
+ *     (err) => fooPromise()
+ *   ]);
+ *
+ *   // do stuff
+ * }
+ *
+ * ```
+ * * * *
+ * @param promises List of promises to try one by one with the order
+ * @returns
+ */
+export async function tryOneByOne<T>(promises: Array<Promise<T> | ((lastError: unknown) => Promise<T>)>): Promise<T> {
+   return await tryPromises([...promises], null);
+}
+
+async function tryPromises<T>(promises: Array<Promise<T> | ((lastError: unknown) => Promise<T>)>, lastError: unknown): Promise<T> {
+  const promiseFn = promises.shift();
+
+  if (!promiseFn) throw lastError;
+
+  try {
+    const promise = typeof promiseFn === "function" ? promiseFn(lastError) : promiseFn;
+
+    return await promise;
+  } catch (err) {
+    return tryPromises(promises, err);
+  }
+}