chore: import upstream snapshot with attribution

packages/shared/src/utils/validate.ts

@@ -0,0 +1,58 @@
+type Valid = {
+  valid: true;
+  error: null;
+};
+
+type Invalid = {
+  valid: false;
+  error: string;
+};
+
+type Validated = Valid | Invalid;
+
+export const invalidCharError: Invalid = {
+  valid: false,
+  error: 'contains invalid characters'
+};
+export const validationSuccess: Valid = { valid: true, error: null };
+export const usernameTooShort: Invalid = {
+  valid: false,
+  error: 'is too short'
+};
+export const usernameIsHttpStatusCode: Invalid = {
+  valid: false,
+  error: 'is a reserved error code'
+};
+
+const validCharsRE = /^[a-zA-Z0-9\-_+]*$/;
+export const isHttpStatusCode = (str: string): boolean => {
+  const output = parseInt(str, 10);
+  return !isNaN(output) && output >= 100 && output <= 599;
+};
+
+export const isValidUsername = (str: string): Validated => {
+  if (!validCharsRE.test(str)) return invalidCharError;
+  if (str.length < 3) return usernameTooShort;
+  if (isHttpStatusCode(str)) return usernameIsHttpStatusCode;
+  return validationSuccess;
+};
+
+// link template:
+// https://learn.microsoft.com/LOCALE/users/USERNAME/transcript/ID
+export const isMicrosoftTranscriptLink = (value: string): boolean => {
+  let url;
+  try {
+    url = new URL(value);
+  } catch {
+    return false;
+  }
+
+  const correctDomain = url.hostname === 'learn.microsoft.com';
+  const correctPath = !!url.pathname.match(
+    /^\/[^/]+\/users\/[^/]+\/transcript\/[^/]+$/
+  );
+  const notPlaceholder = !url.pathname.match(
+    '/LOCALE/users/USERNAME/transcript/ID'
+  );
+  return correctDomain && correctPath && notPlaceholder;
+};