fix(sessions): use custom lists of adjectives and nouns for generating session names (#2122)

* Create custom lists of adjectives and nouns for generating session names

* move word lists to const slices

* add logic to retry name generation

* refactor

 - reuse the name generator
 - iterator instead of for loop

---------

Co-authored-by: Thomas Linford <linford.t@gmail.com>

2 files changed, 170 insertions, 3 deletions

diff --git a/src/commands.rs b/src/commands.rs
index 697f7057f..6e5608e10 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -2,7 +2,7 @@ use dialoguer::Confirm;
 use std::{fs::File, io::prelude::*, path::PathBuf, process};
 
 use crate::sessions::{
-    assert_session, assert_session_ne, get_active_session, get_sessions,
+    assert_session, assert_session_ne, get_active_session, get_name_generator, get_sessions,
     get_sessions_sorted_by_mtime, kill_session as kill_session_impl, match_session_name,
     print_sessions, print_sessions_with_index, session_exists, ActiveSession, SessionNameMatch,
 };
@@ -93,7 +93,7 @@ pub(crate) fn start_server(path: PathBuf, debug: bool) {
 }
 
 fn create_new_client() -> ClientInfo {
-    ClientInfo::New(names::Generator::default().next().unwrap())
+    ClientInfo::New(generate_unique_session_name())
 }
 
 fn find_indexed_session(
@@ -446,7 +446,7 @@ pub(crate) fn start_client(opts: CliArgs) {
                 process::exit(0);
             }
 
-            let session_name = names::Generator::default().next().unwrap();
+            let session_name = generate_unique_session_name();
             start_client_plan(session_name.clone());
             start_client_impl(
                 Box::new(os_input),
@@ -459,3 +459,22 @@ pub(crate) fn start_client(opts: CliArgs) {
         }
     }
 }
+
+fn generate_unique_session_name() -> String {
+    let sessions = get_sessions();
+    let Ok(sessions) = sessions else {
+        eprintln!("Failed to list existing sessions: {:?}", sessions);
+        process::exit(1);
+    };
+
+    let name = get_name_generator()
+        .take(1000)
+        .find(|name| !sessions.contains(name));
+
+    if let Some(name) = name {
+        return name;
+    } else {
+        eprintln!("Failed to generate a unique session name, giving up");
+        process::exit(1);
+    }
+}
diff --git a/src/sessions.rs b/src/sessions.rs
index 9c7de37e9..910bd333b 100644
--- a/src/sessions.rs
+++ b/src/sessions.rs
@@ -219,3 +219,151 @@ pub(crate) fn assert_session_ne(name: &str) {
     };
     process::exit(1);
 }
+
+/// Create a new random name generator
+///
+/// Used to provide a memorable handle for a session when users don't specify a session name when the session is
+/// created.
+///
+/// Uses the list of adjectives and nouns defined below, with the intention of avoiding unfortunate
+/// and offensive combinations. Care should be taken when adding or removing to either list due to the birthday paradox/
+/// hash collisions, e.g. with 4096 unique names, the likelihood of a collision in 10 session names is 1%.
+pub(crate) fn get_name_generator() -> impl Iterator<Item = String> {
+    names::Generator::new(&ADJECTIVES, &NOUNS, names::Name::Plain)
+}
+
+const ADJECTIVES: &[&'static str] = &[
+    "adamant",
+    "adept",
+    "adventurous",
+    "arcadian",
+    "auspicious",
+    "awesome",
+    "blossoming",
+    "brave",
+    "charming",
+    "chatty",
+    "circular",
+    "considerate",
+    "cubic",
+    "curious",
+    "delighted",
+    "didactic",
+    "diligent",
+    "effulgent",
+    "erudite",
+    "excellent",
+    "exquisite",
+    "fabulous",
+    "fascinating",
+    "friendly",
+    "glowing",
+    "gracious",
+    "gregarious",
+    "hopeful",
+    "implacable",
+    "inventive",
+    "joyous",
+    "judicious",
+    "jumping",
+    "kind",
+    "likable",
+    "loyal",
+    "lucky",
+    "marvellous",
+    "mellifluous",
+    "nautical",
+    "oblong",
+    "outstanding",
+    "polished",
+    "polite",
+    "profound",
+    "quadratic",
+    "quiet",
+    "rectangular",
+    "remarkable",
+    "rusty",
+    "sensible",
+    "sincere",
+    "sparkling",
+    "splendid",
+    "stellar",
+    "tenacious",
+    "tremendous",
+    "triangular",
+    "undulating",
+    "unflappable",
+    "unique",
+    "verdant",
+    "vitreous",
+    "wise",
+    "zippy",
+];
+
+const NOUNS: &[&'static str] = &[
+    "aardvark",
+    "accordion",
+    "apple",
+    "apricot",
+    "bee",
+    "brachiosaur",
+    "cactus",
+    "capsicum",
+    "clarinet",
+    "cowbell",
+    "crab",
+    "cuckoo",
+    "cymbal",
+    "diplodocus",
+    "donkey",
+    "drum",
+    "duck",
+    "echidna",
+    "elephant",
+    "foxglove",
+    "galaxy",
+    "glockenspiel",
+    "goose",
+    "hill",
+    "horse",
+    "iguanadon",
+    "jellyfish",
+    "kangaroo",
+    "lake",
+    "lemon",
+    "lemur",
+    "magpie",
+    "megalodon",
+    "mountain",
+    "mouse",
+    "muskrat",
+    "newt",
+    "oboe",
+    "ocelot",
+    "orange",
+    "panda",
+    "peach",
+    "pepper",
+    "petunia",
+    "pheasant",
+    "piano",
+    "pigeon",
+    "platypus",
+    "quasar",
+    "rhinoceros",
+    "river",
+    "rustacean",
+    "salamander",
+    "sitar",
+    "stegosaurus",
+    "tambourine",
+    "tiger",
+    "tomato",
+    "triceratops",
+    "ukulele",
+    "viola",
+    "weasel",
+    "xylophone",
+    "yak",
+    "zebra",
+];