Adopt unmigrate for schema reverts (#260)

butane_cli/src/lib.rs

@@ -277,17 +277,17 @@ pub fn migrate(base_dir: &PathBuf, name: Option<String>) -> Result<()> {
     Ok(())
 }
 
-pub fn rollback(base_dir: &PathBuf, name: Option<String>) -> Result<()> {
+pub fn unmigrate(base_dir: &PathBuf, name: Option<String>) -> Result<()> {
     let spec = load_connspec(base_dir)?;
     let conn = butane::db::connect(&spec)?;
 
     match name {
-        Some(to) => rollback_to(base_dir, conn, &to),
-        None => rollback_latest(base_dir, conn),
+        Some(to) => unmigrate_to(base_dir, conn, &to),
+        None => unmigrate_latest(base_dir, conn),
     }
 }
 
-pub fn rollback_to(base_dir: &Path, mut conn: Connection, to: &str) -> Result<()> {
+pub fn unmigrate_to(base_dir: &Path, mut conn: Connection, to: &str) -> Result<()> {
     let ms = get_migrations(base_dir)?;
     let to_migration = match ms.get_migration(to) {
         Some(m) => m,
@@ -309,15 +309,14 @@ pub fn rollback_to(base_dir: &Path, mut conn: Connection, to: &str) -> Result<()
         });
 
     if to_migration == latest {
-        eprintln!("That is the latest applied migration, not rolling back to anything.");
+        eprintln!("That is the latest migration. No schema change required.");
         std::process::exit(1);
     }
 
     let mut to_unapply = ms.migrations_since(&to_migration)?;
     if to_unapply.is_empty() {
         return Err(anyhow::anyhow!(
-            "That is the latest migration, not rolling back to anything.
-If you expected something to happen, try specifying the migration to rollback to."
+            "That is the latest migration. No schema change required."
         ));
     }
 
@@ -336,7 +335,7 @@ If you expected something to happen, try specifying the migration to rollback to
     Ok(())
 }
 
-pub fn rollback_latest(base_dir: &Path, mut conn: Connection) -> Result<()> {
+pub fn unmigrate_latest(base_dir: &Path, mut conn: Connection) -> Result<()> {
     match get_migrations(base_dir)?.last_applied_migration(&conn)? {
         Some(m) => {
             println!("Rolling back migration {}", m.name());

butane_cli/src/main.rs

@@ -7,7 +7,7 @@ use butane_cli::{
     add_backend, base_dir, clean, clear_data, collapse_migrations, delete_table,
     describe_migration, detach_latest_migration, embed, get_migrations, handle_error, init,
     list_backends, list_migrations, make_migration, migrate, regenerate_migrations, remove_backend,
-    rollback,
+    unmigrate,
 };
 use clap::{ArgAction, Parser, Subcommand};
 
@@ -73,8 +73,9 @@ However if the migration has been manually edited, it will need to be manually r
     },
     /// Embed migrations in the source code.
     Embed,
-    /// Rollback migrations. With no arguments, undoes the latest migration. If the name of a migration is specified, rolls back until that migration is the latest applied migration.
-    Rollback {
+    /// Undo migrations. With no arguments, undoes the latest migration. If the name of a migration is specified, rolls back until that migration is the latest applied migration.
+    #[command(alias = "rollback")]
+    Unmigrate {
         /// Migration to roll back to.
         name: Option<String>,
     },
@@ -177,7 +178,7 @@ fn main() {
         Commands::Regenerate => handle_error(regenerate_migrations(&base_dir)),
         Commands::DetachMigration => handle_error(detach_latest_migration(&base_dir)),
         Commands::Migrate { name } => handle_error(migrate(&base_dir, name.to_owned())),
-        Commands::Rollback { name } => handle_error(rollback(&base_dir, name.to_owned())),
+        Commands::Unmigrate { name } => handle_error(unmigrate(&base_dir, name.to_owned())),
         Commands::Embed => handle_error(embed(&base_dir)),
         Commands::List => handle_error(list_migrations(&base_dir)),
         Commands::Collapse { name } => handle_error(collapse_migrations(&base_dir, Some(name))),

examples/getting_started/tests/rollback.rs → examples/getting_started/tests/unmigrate.rs

@@ -34,7 +34,7 @@ fn insert_data(connection: &Connection) {
     post.save(connection).unwrap();
 }
 
-fn migrate_and_rollback(mut connection: Connection) {
+fn migrate_and_unmigrate(mut connection: Connection) {
     // Migrate forward.
     let base_dir = std::path::PathBuf::from(".butane");
     let migrations = butane_cli::get_migrations(&base_dir).unwrap();
@@ -43,7 +43,7 @@ fn migrate_and_rollback(mut connection: Connection) {
 
     insert_data(&connection);
 
-    // Rollback migrations.
+    // Undo migrations.
     migrations.unmigrate(&mut connection).unwrap();
 }
-testall_no_migrate!(migrate_and_rollback);
+testall_no_migrate!(migrate_and_unmigrate);

examples/newtype/tests/rollback.rs → examples/newtype/tests/unmigrate.rs

@@ -27,7 +27,7 @@ fn insert_data(connection: &Connection) {
     post.save(connection).unwrap();
 }
 
-fn migrate_and_rollback(mut connection: Connection) {
+fn migrate_and_unmigrate(mut connection: Connection) {
     // Migrate forward.
     let base_dir = std::path::PathBuf::from(".butane");
     let migrations = butane_cli::get_migrations(&base_dir).unwrap();
@@ -36,7 +36,7 @@ fn migrate_and_rollback(mut connection: Connection) {
 
     insert_data(&connection);
 
-    // Rollback migrations.
+    // Undo migrations.
     migrations.unmigrate(&mut connection).unwrap();
 }
-testall_no_migrate!(migrate_and_rollback);
+testall_no_migrate!(migrate_and_unmigrate);