From 7254d6ef23011444f3c17ec20071e36c345e754a Mon Sep 17 00:00:00 2001
From: Benny Neugebauer <mail@bennycode.com>
Date: Mon, 13 Jan 2025 23:34:38 +0100
Subject: [PATCH] refactor: Return values from multiple updates

---
 src/Indicator.test.ts               |  8 ++++++++
 src/Indicator.ts                    |  5 ++---
 src/util/getLastFromForEach.test.ts |  9 ---------
 src/util/getLastFromForEach.ts      | 12 ------------
 src/util/index.ts                   |  1 -
 5 files changed, 10 insertions(+), 25 deletions(-)
 delete mode 100644 src/util/getLastFromForEach.test.ts
 delete mode 100644 src/util/getLastFromForEach.ts

diff --git a/src/Indicator.test.ts b/src/Indicator.test.ts
index 77fe4215..0a7975fb 100644
--- a/src/Indicator.test.ts
+++ b/src/Indicator.test.ts
@@ -107,4 +107,12 @@ describe('Indicator', () => {
       expect(itc.highest?.toString()).toBe('97');
     });
   });
+
+  describe('updates', () => {
+    it('returns all values from individual updates', () => {
+      const itc = new IndicatorTestClass();
+      const results = itc.updates([100, 1_000, 10_000]);
+      expect(results.map(big => big?.toString())).toEqual(['100', '550', '3700']);
+    });
+  });
 });
diff --git a/src/Indicator.ts b/src/Indicator.ts
index d6914418..fefb71be 100644
--- a/src/Indicator.ts
+++ b/src/Indicator.ts
@@ -1,6 +1,5 @@
 import type {BigSource} from 'big.js';
 import {NotEnoughDataError} from './error/NotEnoughDataError.js';
-import {getLastFromForEach} from './util/getLastFromForEach.js';
 
 type Nullable<Result> = Result | null;
 
@@ -11,7 +10,7 @@ interface Indicator<Result = Big, Input = BigSource> {
   getResultOrThrow(): Result;
   replace(input: Input): Nullable<Result>;
   update(input: Input, replace: boolean): Nullable<Result>;
-  updates(input: Input[], replace: boolean): Nullable<Result>;
+  updates(input: Input[], replace: boolean): Nullable<Result>[];
 }
 
 export abstract class TechnicalIndicator<Result, Input> implements Indicator<Result, Input> {
@@ -48,7 +47,7 @@ export abstract class TechnicalIndicator<Result, Input> implements Indicator<Res
   abstract update(input: Input, replace: boolean): Result | null;
 
   updates(inputs: readonly Input[], replace: boolean = false) {
-    return getLastFromForEach(inputs, input => this.update(input, replace));
+    return inputs.map(input => this.update(input, replace));
   }
 }
 
diff --git a/src/util/getLastFromForEach.test.ts b/src/util/getLastFromForEach.test.ts
deleted file mode 100644
index c207bd09..00000000
--- a/src/util/getLastFromForEach.test.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-import {getLastFromForEach} from './getLastFromForEach.js';
-
-describe('getLastFromForEach', () => {
-  it('returns the last value from an forEach execution', () => {
-    const array = [1, 2, 3, 4];
-    const result = getLastFromForEach(array, value => value * 2);
-    expect(result).toBe(8);
-  });
-});
diff --git a/src/util/getLastFromForEach.ts b/src/util/getLastFromForEach.ts
deleted file mode 100644
index ad5552a0..00000000
--- a/src/util/getLastFromForEach.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-export function getLastFromForEach<T, R>(
-  array: readonly T[],
-  callback: (value: T, index: number, array: readonly T[]) => R
-): R | null {
-  let lastValue: R | null = null;
-
-  array.forEach((item, index) => {
-    lastValue = callback(item, index, array);
-  });
-
-  return lastValue;
-}
diff --git a/src/util/index.ts b/src/util/index.ts
index c36bc2bf..4c584c8d 100644
--- a/src/util/index.ts
+++ b/src/util/index.ts
@@ -1,6 +1,5 @@
 export * from './BandsResult.js';
 export * from './getAverage.js';
-export * from './getLastFromForEach.js';
 export * from './getMaximum.js';
 export * from './getMinimum.js';
 export * from './getStandardDeviation.js';