feat(plugin-storage-fs): implement the first version of the File System Storage plugin

packages/plugin-storage-fs/README.md

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+# @emigrate/plugin-storage-fs
+
+A file system storage plugin for Emigrate, suitable for simple migration setups. To support containerized environments, it is recommended to use a database storage plugin instead.
+
+## Installation
+
+Install the plugin in your project, alongside the Emigrate CLI:
+
+```bash
+npm install --save-dev @emigrate/cli @emigrate/plugin-storage-fs
+```
+
+## Usage
+
+Configure the plugin in your `emigrate.config.js` file:
+
+```js
+import storageFs from '@emigrate/plugin-storage-fs';
+
+export default {
+  directory: 'migrations',
+  plugins: [storageFs({ filename: '.migrated.json' })],
+};
+```

packages/plugin-storage-fs/package.json

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+{
+  "name": "@emigrate/plugin-storage-fs",
+  "version": "0.0.0",
+  "publishConfig": {
+    "access": "public"
+  },
+  "description": "A storage plugin for Emigrate for storing the migration history in a file",
+  "main": "dist/index.js",
+  "types": "dist/index.d.js",
+  "type": "module",
+  "exports": {
+    ".": {
+      "import": "./dist/index.js",
+      "types": "./dist/index.d.ts"
+    }
+  },
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "build": "tsc --pretty",
+    "build:watch": "tsc --pretty --watch"
+  },
+  "keywords": [
+    "emigrate",
+    "emigrate-plugin",
+    "plugin",
+    "migrations",
+    "storage"
+  ],
+  "author": "Aboviq AB <dev@aboviq.com> (https://www.aboviq.com)",
+  "homepage": "https://github.com/aboviq/emigrate/tree/main/packages/plugin-storage-fs#readme",
+  "repository": "https://github.com/aboviq/emigrate/tree/main/packages/plugin-storage-fs",
+  "bugs": "https://github.com/aboviq/emigrate/issues",
+  "license": "MIT",
+  "dependencies": {
+    "@emigrate/plugin-tools": "workspace:*"
+  },
+  "devDependencies": {
+    "@emigrate/tsconfig": "workspace:*"
+  },
+  "volta": {
+    "extends": "../../package.json"
+  }
+}

packages/plugin-storage-fs/src/index.ts

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+import fs from 'node:fs/promises';
+import path from 'node:path';
+import process from 'node:process';
+import { type StoragePlugin, type MigrationStatus } from '@emigrate/plugin-tools/types';
+
+export type StorageFsOptions = {
+  filename: string;
+};
+
+type SerializedError = {
+  name: string;
+  message: string;
+  stack?: string;
+};
+
+export default function storageFs({ filename }: StorageFsOptions): StoragePlugin {
+  const filePath = path.resolve(process.cwd(), filename);
+  const lockFilePath = `${filePath}.lock`;
+
+  const read = async (): Promise<
+    Record<string, { status: MigrationStatus; date: string; error?: SerializedError }>
+  > => {
+    try {
+      const contents = await fs.readFile(filePath, 'utf8');
+
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+      return JSON.parse(contents);
+    } catch {
+      return {};
+    }
+  };
+
+  let lastUpdate: Promise<void> = Promise.resolve();
+
+  const update = async (migration: string, status: MigrationStatus, error?: Error) => {
+    lastUpdate = lastUpdate.then(async () => {
+      const history = await read();
+
+      const newHistory = {
+        ...history,
+        [migration]: {
+          status,
+          date: new Date().toISOString(),
+          error: error ? { name: error.name, message: error.message, stack: error.stack } : undefined,
+        },
+      };
+
+      await fs.writeFile(filePath, JSON.stringify(newHistory, undefined, 2));
+    });
+
+    return lastUpdate;
+  };
+
+  return {
+    async initializeStorage() {
+      return {
+        async lock(migrations) {
+          const fd = await fs.open(lockFilePath, 'wx');
+
+          await fd.close();
+
+          return migrations;
+        },
+        async unlock() {
+          try {
+            await fs.unlink(lockFilePath);
+          } catch {
+            // Ignore
+          }
+        },
+        async *getHistory() {
+          const history = await read();
+
+          yield* Object.entries(history).map(([name, { status, date, error }]) => ({
+            name,
+            status,
+            error,
+            date: new Date(date),
+          }));
+        },
+        async onSuccess(migration) {
+          await update(migration, 'done');
+        },
+        async onError(migration, error) {
+          await update(migration, 'failed', error);
+        },
+      };
+    },
+  };
+}

packages/plugin-storage-fs/tsconfig.json

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+{
+  "extends": "@emigrate/tsconfig/build.json",
+  "compilerOptions": {
+    "outDir": "dist"
+  },
+  "include": ["src"],
+  "exclude": ["node_modules", "dist"]
+}