feat(cli): add migrations table

feat(cli): implement upgrade database subcommand
feat(cli): add available migrations to list subcommand

migra-cli/src/config.rs

@@ -1,4 +1,6 @@
+use crate::database;
 use crate::path::PathBuilder;
+use postgres::Client;
 use serde::{Deserialize, Serialize};
 use std::path::{Path, PathBuf};
 use std::{fs, io};
@@ -88,6 +90,51 @@ impl Config {
     }
 }
 
+pub struct Migration {
+    upgrade_sql: PathBuf,
+    downgrade_sql: PathBuf,
+    name: String,
+}
+
+impl Migration {
+    fn new(directory: &PathBuf) -> Option<Migration> {
+        if directory.is_dir() {
+            let name = directory
+                .file_name()
+                .and_then(|name| name.to_str())
+                .unwrap_or_default();
+            let upgrade_sql = PathBuilder::from(directory).append("up.sql").build();
+            let downgrade_sql = PathBuilder::from(directory).append("down.sql").build();
+
+            if upgrade_sql.exists() && downgrade_sql.exists() {
+                return Some(Migration {
+                    upgrade_sql,
+                    downgrade_sql,
+                    name: String::from(name),
+                });
+            }
+        }
+
+        None
+    }
+
+    pub fn name(&self) -> &String {
+        &self.name
+    }
+
+    pub fn upgrade(&self, client: &mut Client) -> Result<(), Box<dyn std::error::Error + 'static>> {
+        let content = fs::read_to_string(&self.upgrade_sql)?;
+
+        database::create_migration_table(client)?;
+
+        database::apply_sql(client, &content)?;
+
+        database::insert_migration_info(client, self.name())?;
+
+        Ok(())
+    }
+}
+
 impl Config {
     pub fn directory_path(&self) -> PathBuf {
         PathBuilder::from(&self.root)
@@ -101,7 +148,7 @@ impl Config {
             .build()
     }
 
-    pub fn migration_dirs(&self) -> io::Result<Vec<PathBuf>> {
+    pub fn migrations(&self) -> io::Result<Vec<Migration>> {
         let mut entries = self
             .migration_dir_path()
             .read_dir()?
@@ -110,15 +157,11 @@ impl Config {
 
         entries.sort();
 
-        let migration_dir_entries = entries
-            .into_iter()
-            .filter(|entry| {
-                entry.is_dir()
-                    && PathBuilder::from(entry).append("up.sql").build().exists()
-                    && PathBuilder::from(entry).append("down.sql").build().exists()
-            })
+        let migrations = entries
+            .iter()
+            .filter_map(Migration::new)
             .collect::<Vec<_>>();
 
-        Ok(migration_dir_entries)
+        Ok(migrations)
     }
 }

migra-cli/src/database.rs

@@ -7,3 +7,36 @@ pub fn connect(connection_string: &str) -> Result<Client, Error> {
 pub fn apply_sql(client: &mut Client, sql_content: &str) -> Result<(), Error> {
     client.batch_execute(sql_content)
 }
+
+pub fn is_migration_table_not_found(e: &Error) -> bool {
+    e.to_string()
+        .contains(r#"relation "migrations" does not exist"#)
+}
+
+pub fn applied_migrations(client: &mut Client) -> Result<Vec<String>, Error> {
+    let res = client
+        .query("SELECT name FROM migrations ORDER BY id DESC", &[])
+        .or_else(|e| {
+            if is_migration_table_not_found(&e) {
+                Ok(Vec::new())
+            } else {
+                Err(e)
+            }
+        })?;
+
+    Ok(res.into_iter().map(|row| row.get(0)).collect())
+}
+
+pub fn create_migration_table(client: &mut Client) -> Result<(), Error> {
+    apply_sql(
+        client,
+        r#"CREATE TABLE IF NOT EXISTS migrations (
+            id      serial      PRIMARY KEY,
+            name    text        NOT NULL UNIQUE
+        )"#,
+    )
+}
+
+pub fn insert_migration_info(client: &mut Client, name: &str) -> Result<u64, Error> {
+    client.execute("INSERT INTO migrations (name) VALUES ($1)", &[&name])
+}

migra-cli/src/main.rs

@@ -80,20 +80,55 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         Command::List => {
             let config = Config::read(opt.config)?;
 
-            let migration_dirs = config.migration_dirs()?;
-            if migration_dirs.is_empty() {
-                println!(
-                    "You haven't migrations in {}",
-                    config.directory_path().to_str().unwrap()
-                );
+            let mut client = database::connect(&config.database.connection)?;
+            let applied_migrations = database::applied_migrations(&mut client)?;
+
+            println!("Applied migrations:");
+            if applied_migrations.is_empty() {
+                println!("–")
             } else {
-                migration_dirs.iter().for_each(|dir| {
-                    let file_name = dir.file_name().and_then(|name| name.to_str()).unwrap();
-                    println!("{}", file_name);
+                applied_migrations
+                    .iter()
+                    .for_each(|name| println!("{}", name));
+            }
+
+            let pending_migrations = config.migrations()?
+                .into_iter()
+                .filter(|m| !applied_migrations.contains(m.name()))
+                .collect::<Vec<_>>();
+            println!("Pending migrations:");
+            if pending_migrations.is_empty() {
+                println!("–");
+            } else {
+                pending_migrations.iter().for_each(|m| {
+                    println!("{}", m.name());
                 });
             }
         }
-        Command::Upgrade | Command::Downgrade => {
+        Command::Upgrade => {
+            let config = Config::read(opt.config)?;
+
+            let mut client = database::connect(&config.database.connection)?;
+
+            let applied_migrations = database::applied_migrations(&mut client)?;
+
+            let migrations = config.migrations()?;
+
+            if migrations.is_empty()
+                || migrations.last().map(|m| m.name()) == applied_migrations.first()
+            {
+                println!("Up to date");
+            } else {
+                for m in migrations
+                    .iter()
+                    .filter(|m| !applied_migrations.contains(m.name()))
+                {
+                    println!("{}", m.name());
+                    m.upgrade(&mut client)?;
+                }
+            }
+        }
+        Command::Downgrade => {
             unimplemented!();
         }
     }

sample/database/migrations/210206002058_hello_world/down.sql

@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+

sample/database/migrations/210206002058_hello_world/up.sql

@@ -0,0 +1,2 @@
+-- Your SQL goes here
+

sample/database/migrations/210206002359_second_migration/down.sql

@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+

sample/database/migrations/210206002359_second_migration/up.sql

@@ -0,0 +1,2 @@
+-- Your SQL goes here
+