From ddb9925e18ca37fbe1ba49fc15307ba7e9da7af6 Mon Sep 17 00:00:00 2001
From: Loosetooth <loosetooth@protonmail.com>
Date: Sat, 1 Feb 2025 22:56:58 +0100
Subject: [PATCH] add kata

---
 5kyu/a-chain-adding-function/description.md | 25 +++++++++++++++++++++
 5kyu/a-chain-adding-function/solution.ts    |  8 +++++++
 5kyu/a-chain-adding-function/tests.ts       | 14 ++++++++++++
 3 files changed, 47 insertions(+)
 create mode 100644 5kyu/a-chain-adding-function/description.md
 create mode 100644 5kyu/a-chain-adding-function/solution.ts
 create mode 100644 5kyu/a-chain-adding-function/tests.ts

diff --git a/5kyu/a-chain-adding-function/description.md b/5kyu/a-chain-adding-function/description.md
new file mode 100644
index 0000000..e22ed9a
--- /dev/null
+++ b/5kyu/a-chain-adding-function/description.md
@@ -0,0 +1,25 @@
+We want to create a function that will add numbers together when called in succession.
+```ts
+add(1)(2); // == 3
+```
+We also want to be able to continue to add numbers to our chain.
+```ts
+add(1)(2)(3); // == 6
+add(1)(2)(3)(4); //  == 10
+add(1)(2)(3)(4)(5); // == 15
+```
+and so on.
+
+A single call should be equal to the number passed in.
+```ts
+add(1); // == 1
+```
+We should be able to store the returned values and reuse them.
+```ts
+var addTwo = add(2);
+addTwo; // == 2
+addTwo + 5; // == 7
+addTwo(3); // == 5
+addTwo(3)(5); // == 10
+```
+We can assume any number being passed in will be valid whole number.
\ No newline at end of file
diff --git a/5kyu/a-chain-adding-function/solution.ts b/5kyu/a-chain-adding-function/solution.ts
new file mode 100644
index 0000000..9ddc007
--- /dev/null
+++ b/5kyu/a-chain-adding-function/solution.ts
@@ -0,0 +1,8 @@
+
+export default function add(x: number): any {
+  const sum = (y: number): any => add(x + y);
+  // set .valueOf to return the current sum when the object is coerced to a primitive
+  // for example, when it is compared to a number
+  sum.valueOf = () => x;
+  return sum;
+}
\ No newline at end of file
diff --git a/5kyu/a-chain-adding-function/tests.ts b/5kyu/a-chain-adding-function/tests.ts
new file mode 100644
index 0000000..aca55ce
--- /dev/null
+++ b/5kyu/a-chain-adding-function/tests.ts
@@ -0,0 +1,14 @@
+import add from './solution';
+import {assert} from "chai";
+
+describe('solution', () => {
+  it('should work when called once', () => {
+    assert(add(1) == 1);
+  });
+  it('should work when called twice', () => {
+    assert(add(1)(2) == 3);
+  });
+  it('should work when called 5 times', () => {
+    assert(add(1)(2)(3)(4)(5) == 15);
+  });
+});
\ No newline at end of file