feat: implement migrate cli: metasql m [version]

Refs: #30

PR-URL: #33

Author: tshemsedinov

lib/schema-db.js

@@ -108,7 +108,7 @@ class DatabaseSchema {
   async generate() {
     const { name, driver, version } = this.database;
     const now = new Date().toISOString().substring(0, 10);
-    console.log(`Migration ${driver} database: ${name} v${version} (${now})`);
+    console.log(`Generate migration: ${driver}:${name} v${version} (${now})`);
     const ps = await this.getPreviousSchema();
     if (!ps) {
       console.log('Previous schema is not found in ../history');
@@ -131,6 +131,32 @@ class DatabaseSchema {
     console.log(`Migration up: ${migUp}`);
     console.log(`Migration down: ${migDn}`);
   }
+
+  async migrate(version) {
+    if (version) console.log(`Migration to this version: ${version}`);
+    else console.log('Migration to the latest version');
+    const migPath = path.join(this.path, `migrations`);
+    const files = await fs.readdir(migPath, { withFileTypes: true });
+    files.sort((a, b) => a.name < b.name ? -1 : 1);
+    for (const file of files) {
+      if (file.isDirectory()) continue;
+      const { name } = file;
+      const from = name.lastIndexOf('v') + 1;
+      const to = name.lastIndexOf('-');
+      const v = parseInt(name.substring(from, to), 10);
+      if (!name.endsWith('-up.sql')) continue;
+      if (!version || v <= version) {
+        const fileName = path.join(migPath, name);
+        const sql = await fs.readFile(fileName, 'utf8');
+        console.log(`Apply script: ${name}`);
+        await this.execute(sql);
+      }
+    }
+  }
+
+  async execute(sql) {
+    throw new Error(`Method is not implemented: execute(${sql})`);
+  }
 }
 
 DatabaseSchema.implementations = {};
@@ -145,8 +171,14 @@ const generate = async schemaPath => {
   await schema.generate();
 };
 
+const migrate = async (schemaPath, version) => {
+  const schema = await DatabaseSchema.load(schemaPath);
+  await schema.migrate(version);
+};
+
 module.exports = {
   DatabaseSchema,
   create,
   generate,
+  migrate,
 };

lib/schema-pg.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const { Client } = require('pg');
 const { DatabaseSchema } = require('./schema-db.js');
 const { toLowerCamel, toUpperCamel, isUpperCamel } = require('./utils.js');
 
@@ -109,6 +110,13 @@ class PgSchema extends DatabaseSchema {
     sql.push(');');
     return sql.join('\n') + '\n\n' + idx.join('\n');
   }
+
+  async execute(sql) {
+    const client = new Client(this.database.connection);
+    await client.connect();
+    await client.query(sql);
+    await client.end();
+  }
 }
 
 DatabaseSchema.implementations.pg = PgSchema;

package-lock.json

@@ -52,6 +52,7 @@
     "typescript": "^4.0.2"
   },
   "dependencies": {
-    "@metarhia/common": "^2.2.0"
+    "@metarhia/common": "^2.2.0",
+    "pg": "^8.3.3"
   }
 }

package.json

@@ -5,7 +5,7 @@ const { SelectBuilder } = require('./lib/select-builder.js');
 const { RawBuilder } = require('./lib/raw-builder.js');
 const { ParamsBuilder } = require('./lib/params-builder.js');
 const { PostgresParamsBuilder } = require('./lib/pg-params-builder.js');
-const { create, generate } = require('./lib/schema-db.js');
+const { create, generate, migrate } = require('./lib/schema-db.js');
 require('./lib/schema-pg.js');
 
 const pg = handler => {
@@ -23,5 +23,6 @@ module.exports = {
   PostgresParamsBuilder,
   create,
   generate,
+  migrate,
   pg,
 };