From 46e14461ebb0b1269412b4e3bd5139d2a7da3b12 Mon Sep 17 00:00:00 2001
From: Wez Furlong <wez@wezfurlong.org>
Date: Tue, 11 Jul 2023 08:11:39 -0700
Subject: [PATCH] mux: improve domain name is invalid error message

refs: #3907
---
 mux/src/lib.rs | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/mux/src/lib.rs b/mux/src/lib.rs
index 52f93546d..b0146e2d4 100644
--- a/mux/src/lib.rs
+++ b/mux/src/lib.rs
@@ -1099,9 +1099,20 @@ impl Mux {
             SpawnTabDomain::DomainId(domain_id) => self
                 .get_domain(*domain_id)
                 .ok_or_else(|| anyhow!("domain id {} is invalid", domain_id))?,
-            SpawnTabDomain::DomainName(name) => self
-                .get_domain_by_name(&name)
-                .ok_or_else(|| anyhow!("domain name {} is invalid", name))?,
+            SpawnTabDomain::DomainName(name) => {
+                self.get_domain_by_name(&name).ok_or_else(|| {
+                    let names: Vec<String> = self
+                        .domains_by_name
+                        .read()
+                        .keys()
+                        .map(|name| format!("\"{name}\""))
+                        .collect();
+                    anyhow!(
+                        "domain name \"{name}\" is invalid. Possible names are {}.",
+                        names.join(", ")
+                    )
+                })?
+            }
         };
         Ok(domain)
     }