fix(migrations): don't include folders when collecting migrations

It should be possible to have folders inside your migrations folder

packages/cli/src/get-migrations.ts

@@ -3,37 +3,42 @@ import fs from 'node:fs/promises';
 import { type MigrationMetadata } from '@emigrate/types';
 import { withLeadingPeriod } from './with-leading-period.js';
 import { BadOptionError } from './errors.js';
+import { arrayFromAsync } from './array-from-async.js';
 
 export type GetMigrationsFunction = typeof getMigrations;
 
-const tryReadDirectory = async (directoryPath: string): Promise<string[]> => {
+async function* tryReadDirectory(directoryPath: string): AsyncIterable<string> {
   try {
-    return await fs.readdir(directoryPath);
+    for await (const entry of await fs.opendir(directoryPath)) {
+      if (
+        entry.isFile() &&
+        !entry.name.startsWith('.') &&
+        !entry.name.startsWith('_') &&
+        path.extname(entry.name) !== ''
+      ) {
+        yield entry.name;
+      }
+    }
   } catch {
     throw BadOptionError.fromOption('directory', `Couldn't read directory: ${directoryPath}`);
   }
-};
+}
 
 export const getMigrations = async (cwd: string, directory: string): Promise<MigrationMetadata[]> => {
   const directoryPath = path.resolve(cwd, directory);
 
-  const allFilesInMigrationDirectory = await tryReadDirectory(directoryPath);
+  const allFilesInMigrationDirectory = await arrayFromAsync(tryReadDirectory(directoryPath));
 
-  const migrationFiles: MigrationMetadata[] = allFilesInMigrationDirectory
-    .filter((name) => !name.startsWith('.') && !name.startsWith('_') && path.extname(name) !== '')
-    .sort()
-    .map((name) => {
-      const filePath = path.join(directoryPath, name);
+  return allFilesInMigrationDirectory.sort().map((name) => {
+    const filePath = path.join(directoryPath, name);
 
-      return {
-        name,
-        filePath,
-        relativeFilePath: path.relative(cwd, filePath),
-        extension: withLeadingPeriod(path.extname(name)),
-        directory,
-        cwd,
-      };
-    });
-
-  return migrationFiles;
+    return {
+      name,
+      filePath,
+      relativeFilePath: path.relative(cwd, filePath),
+      extension: withLeadingPeriod(path.extname(name)),
+      directory,
+      cwd,
+    } satisfies MigrationMetadata;
+  });
 };