Take migration title from filename, not exported object, since the fi…

…lesystem already guarantees order and uniqueness

fixtures/dup-ok1.js → fixtures/duplicate/ok1.js

@@ -1,6 +1,5 @@
 
 module.exports = {
-    title: 'OK1',
     up: function(client) {
 
     },

fixtures/ok1.js

@@ -1,6 +1,5 @@
 
 module.exports = {
-    title: 'OK1',
     up: function(client) {
 
     },

fixtures/ok2.js

@@ -1,6 +1,5 @@
 
 module.exports = {
-    title: 'OK2',
     up: function(client) {
 
     },

src/loader.test.ts

@@ -15,18 +15,18 @@ describe('Loader', function() {
     it('Should resolve an OK migration', async function() {
         const loader = new Loader(fixtures, 'ok1.js');
         await expect(loader.load()).resolves.toEqual([
-            expect.objectContaining({title: 'OK1'})
+            expect.objectContaining({title: 'ok1'})
         ]);
     });
     it('Should sort migrations by title', async function() {
         const loader = new Loader(fixtures, ['ok2.js', 'ok1.js']);
         await expect(loader.load()).resolves.toEqual([
-            expect.objectContaining({title: 'OK1'}),
-            expect.objectContaining({title: 'OK2'})
+            expect.objectContaining({title: 'ok1'}),
+            expect.objectContaining({title: 'ok2'})
         ]);
     });
     it('Should require a unique name for each migration', async function() {
-        const loader = new Loader(fixtures, ['ok1.js', 'dup-ok1.js']);
-        await expect(loader.load()).rejects.toThrowError('Duplicate migration detected: OK1');
-    })
+        const loader = new Loader(fixtures, ['ok1.js', 'duplicate/ok1.js']);
+        await expect(loader.load()).rejects.toThrowError('Duplicate migration detected: ok1');
+    });
 })

src/loader.ts

@@ -1,7 +1,7 @@
 import {Migration, MigrationSet} from './migration'
 import glob from 'glob';
 import {promisify} from "util";
-import {join} from 'path'
+import {join, basename} from 'path'
 import Maybe = jest.Maybe;
 
 const globp = promisify(glob);
@@ -31,29 +31,15 @@ export default class Loader {
             throw new Error(`Unable to load migration from ${filename} - this does not look like a JS file.`);
         }
         const prospect = require(join(this.cwd, filename))
-        if(!this.isMigration(prospect)) {
+
+        if(!isMigrationStub(prospect)) {
             throw new Error(`Unable to load migration from ${filename} - this file needs to export an object with a title, up, and down.`);
         }
-        return prospect
+        return Object.assign({}, prospect, {title: basename(filename, '.js')})
     }
     private sort(a: Migration, b: Migration): number {
         return a.title > b.title ? 1 : -1
     }
-    private isMigration(prospect: Maybe<Migration>): prospect is Migration {
-        if(typeof prospect !== 'object' || prospect === null) {
-            return false
-        }
-        if(!('title' in prospect) || !prospect.title.length) {
-            return false
-        }
-        if(!('up' in prospect) || typeof prospect.up !== 'function') {
-            return false;
-        }
-        if(!('down' in prospect) || typeof prospect.down !== 'function') {
-            return false;
-        }
-        return true
-    }
     private assertUnique(migrations: MigrationSet) {
         const seen: {[k: string]: boolean} = {}
         migrations.forEach(function(migration) {
@@ -66,3 +52,18 @@ export default class Loader {
         })
     }
 }
+
+type MigrationStub = Pick<Migration, 'up'|'down'>
+
+function isMigrationStub(prospect: Maybe<MigrationStub>): prospect is MigrationStub {
+    if(typeof prospect !== 'object' || prospect === null) {
+        return false
+    }
+    if(!('up' in prospect) || typeof prospect.up !== 'function') {
+        return false;
+    }
+    if(!('down' in prospect) || typeof prospect.down !== 'function') {
+        return false;
+    }
+    return true
+}

src/migration.ts

@@ -1,6 +1,6 @@
 import {Client as ElasticsearchClient} from "@elastic/elasticsearch";
 
-export interface Migration {
+export type Migration = {
     title: string
     up: (client: ElasticsearchClient) => Promise<void>
     down: (client: ElasticsearchClient) => Promise<void>