ES Modules support

lib/load-migrations.js

@@ -1,7 +1,7 @@
 'use strict'
 
 const path = require('path')
-const fs = require('fs')
+const fs = require('fs').promises
 const Migration = require('./migration')
 
 module.exports = loadMigrationsIntoSet
@@ -22,34 +22,40 @@ function loadMigrationsIntoSet (options, fn) {
   }
 
   // Load from migrations store first up
-  store.load(function (err, state) {
+  store.load(async function (err, state) {
     if (err) return fn(err)
 
-    // Set last run date on the set
-    set.lastRun = state.lastRun || null
+    try {
+      // Set last run date on the set
+      set.lastRun = state.lastRun || null
 
-    // Read migrations directory
-    fs.readdir(migrationsDirectory, function (err, files) {
-      if (err) return fn(err)
+      // Read migrations directory
+      let files = await fs.readdir(migrationsDirectory)
 
       // Filter out non-matching files
       files = files.filter(filterFn)
 
       // Create migrations, keep a lookup map for the next step
       const migMap = {}
-      let migrations = files.map(function (file) {
+      const promises = files.map(async function (file) {
         // Try to load the migrations file
+        const filepath = path.join(migrationsDirectory, file)
         let mod
         try {
-          mod = require(path.join(migrationsDirectory, file))
+          mod = require(filepath)
         } catch (e) {
-          return fn(e)
+          if (e.code === 'ERR_REQUIRE_ESM') {
+            mod = await import(filepath)
+          } else {
+            return fn(e)
+          }
         }
 
         const migration = new Migration(file, mod.up, mod.down, mod.description)
         migMap[file] = migration
         return migration
       })
+      let migrations = await Promise.all(promises)
 
       // Fill in timestamp from state, or error if missing
       state.migrations && state.migrations.forEach(function (m) {
@@ -70,6 +76,8 @@ function loadMigrationsIntoSet (options, fn) {
 
       // Successfully loaded
       fn()
-    })
+    } catch (e) {
+      fn(e)
+    }
   })
 }