From 56c9841a4ae360f9df7e1e6c7092bfa8ae6a050a Mon Sep 17 00:00:00 2001
From: Arild Matsson <arild.matsson@gu.se>
Date: Wed, 20 Sep 2023 16:14:06 +0200
Subject: [PATCH] Random string as util, test it

---
 src/message/messenger.composable.js |  8 ++++++--
 src/util.js                         |  3 +++
 src/util.test.js                    | 10 ++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/message/messenger.composable.js b/src/message/messenger.composable.js
index 6da5b5b..ca0a57f 100644
--- a/src/message/messenger.composable.js
+++ b/src/message/messenger.composable.js
@@ -1,14 +1,18 @@
 import { ref } from "vue";
 import remove from "lodash/remove";
+import { randomString } from "@/util";
 
 const alerts = ref([]); // {key, message, status}[]
 
 export default function useMessenger() {
   function alert(message, status) {
     if (message && status !== "success") {
-      const key = Math.random().toString(36);
       // Add message.
-      alerts.value.push({ key, message, status: status || "debug" });
+      alerts.value.push({
+        key: randomString(),
+        message,
+        status: status || "debug",
+      });
     }
   }
 
diff --git a/src/util.js b/src/util.js
index 8c7d81d..9528408 100644
--- a/src/util.js
+++ b/src/util.js
@@ -58,3 +58,6 @@ export function setKeys(obj, keys, defaultValue = null) {
 
   return obj;
 }
+
+/** Create a random string of around 11 chars in the [0-9a-z] range. */
+export const randomString = () => Math.random().toString(36).slice(2);
diff --git a/src/util.test.js b/src/util.test.js
index 4c574c2..027a6bc 100644
--- a/src/util.test.js
+++ b/src/util.test.js
@@ -4,6 +4,7 @@ import {
   formatDate,
   formatSeconds,
   pathJoin,
+  randomString,
   setKeys,
 } from "./util";
 
@@ -54,3 +55,12 @@ describe("setKeys", () => {
     expect(a).toEqual({ b: 2, c: 10 });
   });
 });
+
+describe("randomString", () => {
+  test("1000 samples match [0-9a-z]", () => {
+    const pattern = new RegExp(/^[0-9a-z]+$/);
+    const samples = Array.from({ length: 1000 }, () => randomString());
+    const fails = samples.filter((s) => !pattern.test(s));
+    expect(fails).toEqual([]);
+  });
+});