feat: how do we create and run migrations (#28)

.circleci/config.yml

@@ -85,6 +85,7 @@ workflows:
               ignore:
                 - master
                 - release
+                - /release-.*/
       - test:
           context: library
           requires:
@@ -94,8 +95,11 @@ workflows:
               ignore:
                 - master
                 - release
+                - /release-.*/
       - deploy:
           context: library
           filters:
             branches:
-              only: release
+              only:
+                - release
+                - /release-.*/

bin/migrate.js

@@ -0,0 +1,41 @@
+#! /usr/bin/env node
+
+const program = require("commander");
+const migrate = require("../dist/migration");
+const pkgjson = require("../package.json");
+
+program.version(pkgjson.version);
+
+program
+  .command("init")
+  .description("initialize a new migration project")
+  .action(() =>
+    migrate
+      .init()
+      .then(() => console.log(`Initialization successful. Check out \`${migrate.DEFAULT_CONFIG_FILE_NAME}\` file`))
+      .catch(err => {
+        console.error(`ERROR: ${err.message}`);
+        process.exit(1);
+      })
+  );
+
+program
+  .command("create [description]")
+  .description("create a new database migration with the provided description")
+  .option("-f --file <file>", "use a custom config file")
+  .action((description, options) => {
+    global.options = options;
+    migrate
+      .create(description)
+      .then(destination => console.log(`Created: ${destination}`))
+      .catch(err => {
+        console.error(`ERROR: ${err.message}`);
+        process.exit(1);
+      });
+  });
+
+program.parse(process.argv);
+
+if (!program.rawArgs || program.rawArgs.length === 0) {
+  program.outputHelp();
+}

package.json

@@ -1,9 +1,12 @@
 {
   "name": "@random-guys/bucket",
-  "version": "0.8.1",
+  "version": "0.9.0-rc.4",
   "description": "Wrapper around axios for interservice communication",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
+  "bin": {
+    "bucket-migrate": "bin/migrate.js"
+  },
   "scripts": {
     "build": "tsc -p ./tsconfig.json",
     "watch": "tsc -w -p ./tsconfig.json",
@@ -20,6 +23,7 @@
   "homepage": "https://github.com/random-guys/bucket#readme",
   "devDependencies": {
     "@types/jest": "^25.2.3",
+    "@types/migrate-mongo": "^7.0.1",
     "@types/mongoose": "^5.5.18",
     "@types/supertest": "^2.0.9",
     "@types/uuid": "^3.4.4",
@@ -29,10 +33,14 @@
     "typescript": "^3.5.2"
   },
   "files": [
-    "dist/"
+    "dist/",
+    "samples/"
   ],
   "dependencies": {
+    "commander": "^5.1.0",
+    "date-fns": "^2.14.0",
     "http-status-codes": "^1.3.2",
+    "migrate-mongo": "^7.2.1",
     "mongoose": "^5.7.1",
     "uuid": "^3.3.2"
   }

samples/migrate-mongo-config.js

@@ -0,0 +1,15 @@
+// In this file you can configure migrate-mongo
+
+const config = {
+  // The migrations dir, can be an relative or absolute path. Only edit this when really necessary.
+  migrationsDir: "dist/migrations",
+
+  // The mongodb collection where the applied changes are stored. Only edit this when really necessary.
+  changelogCollectionName: "changelog",
+
+  // The file extension to create migrations and search for in migration dir
+  migrationFileExtension: ".js"
+};
+
+// Return the config as a promise
+module.exports = config;

samples/sample-migration.ts

@@ -0,0 +1,13 @@
+import { Db, MongoClient } from "mongodb";
+
+export async function up(db: Db, conn: MongoClient) {
+  // TODO write your migration here.
+  // Example:
+  // await db.collection('albums').updateOne({artist: 'The Beatles'}, {$set: {blacklisted: true}});
+}
+
+export async function down(db: Db, conn: MongoClient) {
+  // TODO write the statements to rollback your migration (if possible)
+  // Example:
+  // await db.collection('albums').updateOne({artist: 'The Beatles'}, {$set: {blacklisted: false}});
+}

src/index.ts

@@ -3,5 +3,6 @@ export * from "./base.repo";
 export * from "./base.schema";
 export * from "./connect";
 export * from "./errors";
+export * from "./migration";
 export * from "./query";
 export * from "./utils.schema";

src/migration.ts

@@ -0,0 +1,68 @@
+import fs from "fs";
+import { down, up, config } from "migrate-mongo";
+import { Connection } from "mongoose";
+import path from "path";
+import format from "date-fns/format";
+
+const PREFIX_FORMAT = "yyyyMMddHHmmss";
+export const DEFAULT_MIGRATION_DIR = "src/migrations";
+export const DEFAULT_CONFIG_FILE_NAME = "migrate-mongo-config.js";
+
+/**
+ * Applies all unapplied migrations to the DB. Note that it passes the mongoose
+ * connection in place of `MongoClient` due to being unable to access
+ * that from mongoose.
+ * @param connection mongoose connection to be used for migration
+ */
+export function migrateUp(connection: Connection) {
+  // @ts-ignore wrong typing
+  return up(connection.db, connection.client);
+}
+
+/**
+ * Undo the last applied migration. Note that it passes the mongoose
+ * connection in place of `MongoClient` due to being unable to access
+ * that from mongoose.
+ * @param connection mongoose connection to be used for migration
+ */
+export function migrateDown(connection: Connection) {
+  // @ts-ignore wrong typing
+  return down(connection.db, connection.client);
+}
+
+export async function create(description: string) {
+  if (!description) {
+    throw new Error("Missing parameter: description");
+  }
+
+  // where should we store the new migration
+  await config.shouldExist();
+  const migrationConfig = await config.read();
+  const configuredDir = migrationConfig.migrationsDir?.replace("dist", "src") ?? DEFAULT_MIGRATION_DIR;
+  const migrationsDir = path.isAbsolute(configuredDir) ? configuredDir : path.join(process.cwd(), configuredDir);
+
+  try {
+    await fs.promises.access(migrationsDir);
+  } catch (err) {
+    throw new Error(`migrations directory does not exist: ${migrationsDir}`);
+  }
+
+  // construct the file name
+  const source = path.join(__dirname, "../samples/sample-migration.ts");
+  const prefix = format(new Date(), PREFIX_FORMAT);
+  const filename = `${prefix}-${description.split(" ").join("_")}.ts`;
+
+  // copy sample file to new file
+  const destination = path.join(migrationsDir, filename);
+  await fs.promises.copyFile(source, destination);
+
+  return destination;
+}
+
+export async function init() {
+  const source = path.join(__dirname, `../samples/${DEFAULT_CONFIG_FILE_NAME}`);
+  const destination = path.join(process.cwd(), DEFAULT_CONFIG_FILE_NAME);
+
+  await fs.promises.copyFile(source, destination);
+  return fs.promises.mkdir(path.join(process.cwd(), "src/migrations"));
+}