From 6b87ca1c4d87f5c3cb9915b87d2ef75b1aebaae0 Mon Sep 17 00:00:00 2001
From: Danish Arora <35004822+danisharora099@users.noreply.github.com>
Date: Mon, 27 Feb 2023 01:01:55 +0530
Subject: [PATCH] chore: move `random_subset.ts` to `@waku/utils` (#1191)

---
 .../src/lib/predefined_bootstrap_nodes.ts     |  2 +-
 packages/dns-discovery/src/index.spec.ts      |  3 +-
 packages/dns-discovery/src/random_subset.ts   | 30 -------------------
 packages/utils/src/common/index.ts            |  1 +
 .../lib => utils/src/common}/random_subset.ts |  0
 packages/utils/src/index.ts                   |  1 +
 6 files changed, 4 insertions(+), 33 deletions(-)
 delete mode 100644 packages/dns-discovery/src/random_subset.ts
 create mode 100644 packages/utils/src/common/index.ts
 rename packages/{core/src/lib => utils/src/common}/random_subset.ts (100%)

diff --git a/packages/core/src/lib/predefined_bootstrap_nodes.ts b/packages/core/src/lib/predefined_bootstrap_nodes.ts
index 69e7f8ad44..3606297f21 100644
--- a/packages/core/src/lib/predefined_bootstrap_nodes.ts
+++ b/packages/core/src/lib/predefined_bootstrap_nodes.ts
@@ -1,4 +1,4 @@
-import { getPseudoRandomSubset } from "./random_subset.js";
+import { getPseudoRandomSubset } from "@waku/utils";
 
 export const DefaultWantedNumber = 1;
 
diff --git a/packages/dns-discovery/src/index.spec.ts b/packages/dns-discovery/src/index.spec.ts
index f237a3cbe8..92cf61b70e 100644
--- a/packages/dns-discovery/src/index.spec.ts
+++ b/packages/dns-discovery/src/index.spec.ts
@@ -1,7 +1,6 @@
+import { getPseudoRandomSubset } from "@waku/utils";
 import { expect } from "chai";
 
-import { getPseudoRandomSubset } from "./random_subset.js";
-
 describe("Discovery", () => {
   it("returns all values when wanted number matches available values", function () {
     const values = ["a", "b", "c"];
diff --git a/packages/dns-discovery/src/random_subset.ts b/packages/dns-discovery/src/random_subset.ts
deleted file mode 100644
index 20d0ca83ce..0000000000
--- a/packages/dns-discovery/src/random_subset.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-/**
- * Return pseudo random subset of the input.
- */
-export function getPseudoRandomSubset<T>(
-  values: T[],
-  wantedNumber: number
-): T[] {
-  if (values.length <= wantedNumber || values.length <= 1) {
-    return values;
-  }
-
-  return shuffle(values).slice(0, wantedNumber);
-}
-
-function shuffle<T>(arr: T[]): T[] {
-  if (arr.length <= 1) {
-    return arr;
-  }
-  const randInt = (): number => {
-    return Math.floor(Math.random() * Math.floor(arr.length));
-  };
-
-  for (let i = 0; i < arr.length; i++) {
-    const j = randInt();
-    const tmp = arr[i];
-    arr[i] = arr[j];
-    arr[j] = tmp;
-  }
-  return arr;
-}
diff --git a/packages/utils/src/common/index.ts b/packages/utils/src/common/index.ts
new file mode 100644
index 0000000000..5f3d35f3c9
--- /dev/null
+++ b/packages/utils/src/common/index.ts
@@ -0,0 +1 @@
+export * from "./random_subset.js";
diff --git a/packages/core/src/lib/random_subset.ts b/packages/utils/src/common/random_subset.ts
similarity index 100%
rename from packages/core/src/lib/random_subset.ts
rename to packages/utils/src/common/random_subset.ts
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index 4737706c59..33c0548d02 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -1,2 +1,3 @@
 export * from "./bytes/index.js";
 export * from "./libp2p/index.js";
+export * from "./common/index.js";