Remove special cased ordering in migration list

Diesel is not meant to have an opinion on versioning. The use of
timestamps is a convention that gives us alphabetically increasing
versions, but we should not give it special treatment. Additionally,
this behavior did not mirror the order in which the migrations will be
run.

Author: sgrif

diesel_cli/src/main.rs

@@ -76,7 +76,6 @@ fn run_migration_command(matches: &ArgMatches) {
             call_with_conn!(database_url, redo_latest_migration(&dir));
         }
         ("list", Some(args)) => {
-            use std::cmp::Ordering;
             use std::ffi::OsStr;
 
             let database_url = database::database_url(matches);
@@ -100,29 +99,7 @@ fn run_migration_command(matches: &ArgMatches) {
                 })
                 .collect::<Vec<_>>();
 
-            // sort migrations by version timestamp, push non-conforming timestamped versions to the bottom
-            sorted.sort_by(|a, b| {
-                let version_a = a.0
-                    .split('_')
-                    .nth(0)
-                    .expect(&format!("Unexpected version format {:?}", a.0));
-                let ver_date_a = Utc.datetime_from_str(version_a, TIMESTAMP_FORMAT);
-                let version_b = b.0
-                    .split('_')
-                    .nth(0)
-                    .expect(&format!("Unexpected version format {:?}", b.0));
-                let ver_date_b = Utc.datetime_from_str(version_b, TIMESTAMP_FORMAT);
-                match (ver_date_a.is_ok(), ver_date_b.is_ok()) {
-                    (false, false) => version_a.to_lowercase().cmp(&version_b.to_lowercase()),
-                    (true, false) => Ordering::Less,
-                    (false, true) => Ordering::Greater,
-                    (true, true) => {
-                        let a = ver_date_a.unwrap();
-                        let b = ver_date_b.unwrap();
-                        a.cmp(&b)
-                    }
-                }
-            });
+            sorted.sort();
 
             println!("Migrations:");
             for (name, applied) in sorted {

diesel_cli/tests/migration_list.rs

@@ -117,7 +117,7 @@ fn migration_list_orders_unknown_timestamps_last() {
 }
 
 #[test]
-fn migration_list_orders_nontimestamp_versions_lexicographically() {
+fn migration_list_orders_nontimestamp_versions_alphabetically() {
     let p = project("migration_list_nontimestamp_versions")
         .folder("migrations")
         .build();
@@ -133,14 +133,14 @@ fn migration_list_orders_nontimestamp_versions_lexicographically() {
     let tag5 = "aa_migration";
     p.create_migration(&tag5, "", "");
 
-    let tag2 = "!wow_migration";
-    p.create_migration(&tag2, "", "");
+    let tag1 = "!wow_migration";
+    p.create_migration(&tag1, "", "");
 
     let tag3 = "7letters";
     p.create_migration(&tag3, "", "");
 
-    let tag1 = format!("{}_stamped_migration", Utc::now().format(TIMESTAMP_FORMAT));
-    p.create_migration(&tag1, "", "");
+    let tag2 = format!("{}_stamped_migration", Utc::now().format(TIMESTAMP_FORMAT));
+    p.create_migration(&tag2, "", "");
 
     let result = p.command("migration").arg("list").run();
     assert!(result.is_success(), "Result was unsuccessful {:?}", result);