build: switch from yarn to npm to manage js dependencies and move js contents to root

yarn v1 is being deprecated and starts to have some issues

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

src/utils/username.ts

@@ -0,0 +1,35 @@
+import { IActor } from "@/types/actor";
+
+function convertToUsername(value: string | null): string {
+  if (!value) return "";
+
+  // https://stackoverflow.com/a/37511463
+  return value
+    .toLocaleLowerCase()
+    .normalize("NFD")
+    .replace(/[\u0300-\u036f]/g, "")
+    .replace(/\s{2,}/, " ")
+    .replace(/ /g, "_")
+    .replace(/[^a-z0-9_]/g, "")
+    .replace(/_{2,}/, "");
+}
+
+function autoUpdateUsername(
+  actor: IActor,
+  newDisplayName: string | null
+): IActor {
+  const actor2 = { ...actor };
+  const oldUsername = convertToUsername(actor.name);
+
+  if (actor.preferredUsername === oldUsername) {
+    actor2.preferredUsername = convertToUsername(newDisplayName);
+  }
+
+  return actor2;
+}
+
+function validateUsername(actor: IActor): boolean {
+  return actor.preferredUsername === convertToUsername(actor.preferredUsername);
+}
+
+export { autoUpdateUsername, convertToUsername, validateUsername };