Add and fixup invite link related tests

src/users.js

@@ -659,6 +659,9 @@ async function sendPasswordResetEmail(user, email, auditSource) {
     assert.strictEqual(typeof email, 'string');
     assert.strictEqual(typeof auditSource, 'object');
 
+    const error = validateEmail(email);
+    if (error) throw error;
+
     const resetLink = await getPasswordResetLink(user, auditSource);
     await mailer.passwordReset(user, email, resetLink);
 }
@@ -767,6 +770,10 @@ async function sendInviteEmail(user, email, auditSource) {
     assert.strictEqual(typeof user, 'object');
     assert.strictEqual(typeof email, 'string');
     assert.strictEqual(typeof auditSource, 'object');
+
+    const error = validateEmail(email);
+    if (error) throw error;
+
     const inviteLink = await getInviteLink(user, auditSource);
     await mailer.sendInvite(user, null /* invitor */, email, inviteLink);
 }