move into Migrations

butane/tests/migration-tests.rs

@@ -344,15 +344,15 @@ fn test_migrate(
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 2);
 
-    migrations::migrate(conn, &ms).unwrap();
+    ms.migrate(conn).unwrap();
 
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 0);
 
     verify_sql(conn, &ms, expected_up_sql, expected_down_sql);
 
     // Now downgrade, just to make sure we can
-    migrations::rollback(conn, &ms).unwrap();
+    ms.unmigrate(conn).unwrap();
 
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 2);
@@ -563,15 +563,15 @@ fn migration_delete_table(conn: &mut Connection, expected_up_sql: &str, expected
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 2);
 
-    migrations::migrate(conn, &ms).unwrap();
+    ms.migrate(conn).unwrap();
 
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 0);
 
     verify_sql(conn, &ms, expected_up_sql, expected_down_sql);
 
     // Now downgrade, just to make sure we can
-    migrations::rollback(conn, &ms).unwrap();
+    ms.unmigrate(conn).unwrap();
 
     let to_apply = ms.unapplied_migrations(conn).unwrap();
     assert_eq!(to_apply.len(), 2);

butane_core/src/migrations/mod.rs

@@ -8,7 +8,7 @@ use std::path::Path;
 use fallible_iterator::FallibleIterator;
 use nonempty::NonEmpty;
 
-use crate::db::BackendRows;
+use crate::db::{BackendConnection, BackendRows};
 use crate::db::{Column, ConnectionMethods};
 use crate::sqlval::{FromSql, SqlValRef, ToSql};
 use crate::{db, query, DataObject, DataResult, Error, PrimaryKeyType, Result, SqlType};
@@ -109,6 +109,34 @@ pub trait Migrations {
         }
         Ok(None)
     }
+
+    /// Migrate connection forward.
+    fn migrate(&self, connection: &mut impl BackendConnection) -> Result<()> {
+        let to_apply = self.unapplied_migrations(connection)?;
+        for migration in &to_apply {
+            crate::info!("Applying migration {}", migration.name());
+            migration.apply(connection)?;
+        }
+        Ok(())
+    }
+
+    /// Remove all applied migrations.
+    fn unmigrate(&self, connection: &mut impl BackendConnection) -> Result<()> {
+        let mut migration = match self.last_applied_migration(connection)? {
+            Some(migration) => migration,
+            None => return Ok(()),
+        };
+        migration.downgrade(connection)?;
+
+        while let Ok(Some(migration_name)) = migration.migration_from() {
+            migration = self
+                .get_migration(&migration_name)
+                .ok_or(Error::MigrationError("Migration not in chain".to_string()))?;
+            crate::info!("Rolling back migration {}", migration.name());
+            migration.downgrade(connection)?;
+        }
+        Ok(())
+    }
 }
 
 /// Extension of [`Migrations`] to modify the series of migrations.
@@ -326,37 +354,3 @@ impl crate::internal::DataObjectInternal for ButaneMigration {
         Ok(()) // no-op
     }
 }
-
-/// Migrate connection forward.
-pub fn migrate<M: Migration>(
-    connection: &mut impl crate::db::BackendConnection,
-    migrations: &impl Migrations<M = M>,
-) -> Result<()> {
-    let to_apply = migrations.unapplied_migrations(connection)?;
-    for migration in &to_apply {
-        crate::info!("Applying migration {}", migration.name());
-        migration.apply(connection)?;
-    }
-    Ok(())
-}
-
-/// Rollback all applied migrations.
-pub fn rollback<M: Migration>(
-    connection: &mut impl crate::db::BackendConnection,
-    migrations: &impl Migrations<M = M>,
-) -> Result<()> {
-    let mut migration = match migrations.last_applied_migration(connection)? {
-        Some(migration) => migration,
-        None => return Ok(()),
-    };
-    migration.downgrade(connection)?;
-
-    while let Ok(Some(migration_name)) = migration.migration_from() {
-        migration = migrations
-            .get_migration(&migration_name)
-            .ok_or(Error::MigrationError("Migration not in chain".to_string()))?;
-        crate::info!("Rolling back migration {}", migration.name());
-        migration.downgrade(connection)?;
-    }
-    Ok(())
-}

butane_test_helper/src/lib.rs

@@ -10,7 +10,7 @@ use std::sync::Mutex;
 
 use block_id::{Alphabet, BlockId};
 use butane_core::db::{connect, get_backend, pg, sqlite, Backend, Connection, ConnectionSpec};
-use butane_core::migrations::{self, MemMigrations, Migration, MigrationsMut};
+use butane_core::migrations::{self, MemMigrations, Migration, Migrations, MigrationsMut};
 use once_cell::sync::Lazy;
 use uuid::Uuid;
 
@@ -209,7 +209,7 @@ pub fn setup_db(backend: Box<dyn Backend>, conn: &mut Connection, migrate: bool)
         "expected to create migration"
     );
     log::info!("created current migration");
-    migrations::migrate(conn, &mem_migrations).unwrap();
+    mem_migrations.migrate(conn).unwrap();
 }
 
 /// Create a sqlite [`Connection`].

docs/getting-started.md

@@ -505,11 +505,11 @@ to use these migrations:
 
 ``` rust
 pub fn establish_connection() -> Connection {
-    use butane::migrations;
+    use butane::migrations::Migrations;
 
     let mut connection = butane::db::connect(&ConnectionSpec::load(".butane/connection.json").unwrap()).unwrap();
     let migrations = butane_migrations::get_migrations().unwrap();
-    migrations::migrate(&mut connection, &migrations).unwrap();
+    migrations.migrate(&mut connection).unwrap();
     connection
 }
 ```

examples/getting_started/src/lib.rs

@@ -6,7 +6,7 @@ pub mod butane_migrations;
 pub mod models;
 
 use butane::db::{Connection, ConnectionSpec};
-use butane::migrations;
+use butane::migrations::Migrations;
 use butane::prelude::*;
 use models::{Blog, Post};
 
@@ -15,7 +15,7 @@ pub fn establish_connection() -> Connection {
     let mut connection =
         butane::db::connect(&ConnectionSpec::load(".butane/connection.json").unwrap()).unwrap();
     let migrations = butane_migrations::get_migrations().unwrap();
-    migrations::migrate(&mut connection, &migrations).unwrap();
+    migrations.migrate(&mut connection).unwrap();
     connection
 }
 

examples/getting_started/tests/rollback.rs

@@ -1,5 +1,5 @@
 use butane::db::{BackendConnection, Connection};
-use butane::migrations;
+use butane::migrations::Migrations;
 use butane::DataObject;
 use butane_test_helper::*;
 
@@ -39,11 +39,11 @@ fn migrate_and_rollback(mut connection: Connection) {
     let base_dir = std::path::PathBuf::from(".butane");
     let migrations = butane_cli::get_migrations(&base_dir).unwrap();
 
-    migrations::migrate(&mut connection, &migrations).unwrap();
+    migrations.migrate(&mut connection).unwrap();
 
     insert_data(&connection);
 
     // Rollback migrations.
-    migrations::rollback(&mut connection, &migrations).unwrap();
+    migrations.unmigrate(&mut connection).unwrap();
 }
 testall_no_migrate!(migrate_and_rollback);

examples/newtype/src/lib.rs

@@ -6,7 +6,7 @@ pub mod butane_migrations;
 pub mod models;
 
 use butane::db::{Connection, ConnectionSpec};
-use butane::migrations;
+use butane::migrations::Migrations;
 use butane::prelude::*;
 use models::{Blog, Post};
 
@@ -15,7 +15,7 @@ pub fn establish_connection() -> Connection {
     let mut connection =
         butane::db::connect(&ConnectionSpec::load(".butane/connection.json").unwrap()).unwrap();
     let migrations = butane_migrations::get_migrations().unwrap();
-    migrations::migrate(&mut connection, &migrations).unwrap();
+    migrations.migrate(&mut connection).unwrap();
     connection
 }
 

examples/newtype/tests/rollback.rs

@@ -33,7 +33,7 @@ fn migrate_and_rollback(mut connection: Connection) {
     let migrations = butane_cli::get_migrations(&base_dir).unwrap();
     let to_apply = migrations.unapplied_migrations(&connection).unwrap();
 
-    migrations::migrate(&mut connection, &migrations).unwrap();
+    migrations.migrate(&mut connection).unwrap();
 
     insert_data(&connection);