refac: add trait for upgrade and downgrade

migra-cli/src/commands/downgrade.rs

@@ -1,5 +1,6 @@
 use crate::config::Config;
 use crate::database::DatabaseConnection;
+use crate::migration::Downgrade;
 use crate::StdResult;
 use std::convert::TryFrom;
 

migra-cli/src/commands/upgrade.rs

@@ -1,5 +1,5 @@
 use crate::database::DatabaseConnection;
-use crate::migration::Migration;
+use crate::migration::{Migration, Upgrade};
 use crate::Config;
 use crate::StdResult;
 use std::convert::TryFrom;

migra-cli/src/migration.rs

@@ -1,8 +1,17 @@
 use crate::database::DatabaseConnection;
 use crate::path::PathBuilder;
+use crate::StdResult;
 use std::fs;
 use std::path::PathBuf;
 
+pub trait Upgrade {
+    fn upgrade(&self, connection: &mut DatabaseConnection) -> StdResult<()>;
+}
+
+pub trait Downgrade {
+    fn downgrade(&self, connection: &mut DatabaseConnection) -> StdResult<()>;
+}
+
 #[derive(Debug)]
 pub struct Migration {
     upgrade_sql: PathBuf,
@@ -31,15 +40,16 @@ impl Migration {
 
         None
     }
+}
 
+impl Migration {
     pub fn name(&self) -> &String {
         &self.name
     }
+}
 
-    pub fn upgrade(
-        &self,
-        connection: &mut DatabaseConnection,
-    ) -> Result<(), Box<dyn std::error::Error + 'static>> {
+impl Upgrade for Migration {
+    fn upgrade(&self, connection: &mut DatabaseConnection) -> StdResult<()> {
         let content = fs::read_to_string(&self.upgrade_sql)?;
 
         connection.create_migrations_table()?;
@@ -48,11 +58,10 @@ impl Migration {
 
         Ok(())
     }
+}
 
-    pub fn downgrade(
-        &self,
-        connection: &mut DatabaseConnection,
-    ) -> Result<(), Box<dyn std::error::Error + 'static>> {
+impl Downgrade for Migration {
+    fn downgrade(&self, connection: &mut DatabaseConnection) -> StdResult<()> {
         let content = fs::read_to_string(&self.downgrade_sql)?;
 
         connection.apply_sql(&content)?;