Add option to remove all documents from collections being seeding

cli/README.md

@@ -62,6 +62,7 @@ You can use the following parameters while using `seed` tool:
 | `--db-options` | *`undefined`* | [MongoDB connection options](https://docs.mongodb.com/manual/reference/connection-string/) in a form of multiple `{key}={value}` values, separated by semicolon. For example: `ssl=true;maxPoolSize=50` |
 | `--drop-database` | `false` | Drops entire database before data import |
 | `--drop-collections` | `false` | Drops every collection which is being imported |
+| `--remove-all-documents` | `false` | Delete all documents from every collection that is being imported |
 | `--replace-id` | `false` | Replaces `id` property with `_id` for every document during data import |
 | `--set-timestamps` | `false` | Sets `createdAt` and `updatedAt` timestamps for every document during data import |
 | `--reconnect-timeout` | `10000` | Maximum time in milliseconds of waiting for successful MongoDB connection |
@@ -85,6 +86,7 @@ You can use the following environmental variables while using `seed` tool:
 | `DB_OPTIONS` | *`undefined`* | [MongoDB connection options](https://docs.mongodb.com/manual/reference/connection-string/) in a form of multiple `{key}={value}` values, separated by semicolon. For example: `ssl=true;maxPoolSize=50`. |
 | `DROP_DATABASE` | `false` | Drops entire database before data import |
 | `DROP_COLLECTIONS` | `false` | Drops every collection which is being imported |
+| `REMOVE_ALL_DOCUMENTS` | `false` | Delete all documents from every collection that is being imported |
 | `REPLACE_ID` | `false` | Replaces `id` property with `_id` for every document during import; useful for ORMs | 
 | `SET_TIMESTAMPS` | `false` | Sets `createdAt` and `updatedAt` timestamps for every document during data import |
 | `RECONNECT_TIMEOUT` | `10000` | Maximum time in milliseconds of waiting for successful MongoDB connection |

cli/src/options.ts

@@ -9,7 +9,7 @@ import { SeederDatabaseConfigObjectOptions } from 'mongo-seeding/dist/database';
 import { Seeder, SeederCollectionReadingOptions } from 'mongo-seeding';
 
 export const DEFAULT_INPUT_PATH = './';
-export const DEFAULT_EXTENSIONS = ['ts', 'js', 'cjs', 'json']
+export const DEFAULT_EXTENSIONS = ['ts', 'js', 'cjs', 'json'];
 
 export const cliOptions: CommandLineOption[] = [
   {
@@ -83,6 +83,12 @@ export const cliOptions: CommandLineOption[] = [
     description: 'Drops every collection that is being imported',
     type: Boolean,
   },
+  {
+    name: 'remove-all-documents',
+    description:
+      'Delete all documents from every collection that is being imported',
+    type: Boolean,
+  },
   {
     name: 'replace-id',
     description:
@@ -134,7 +140,13 @@ export const createConfigFromOptions = (
     },
   };
 
-  const mergedConfig = extend(true, config, defaultConfig, envConfig, commandLineConfig);
+  const mergedConfig = extend(
+    true,
+    config,
+    defaultConfig,
+    envConfig,
+    commandLineConfig,
+  );
   mergedConfig.collectionReading = getCollectionReadingConfig(mergedConfig);
   return mergedConfig;
 };
@@ -183,6 +195,7 @@ function populateCommandLineOptions(
       databaseReconnectTimeout: options['reconnect-timeout'],
       dropDatabase: options['drop-database'],
       dropCollections: options['drop-collections'],
+      removeAllDocuments: options['remove-all-documents'],
     },
     cli: {
       dataPath: options['data'],
@@ -241,6 +254,7 @@ function populateEnvOptions(): PartialCliOptions {
         : undefined,
       dropDatabase: env.DROP_DATABASE === 'true',
       dropCollections: env.DROP_COLLECTIONS === 'true',
+      removeAllDocuments: env.REMOVE_ALL_DOCUMENTS === 'true',
     },
     cli: {
       ejsonParseCanonicalMode:

cli/src/types.ts

@@ -15,6 +15,7 @@ export interface CommandLineArguments {
   silent?: boolean;
   'drop-database'?: boolean;
   'drop-collections'?: boolean;
+  'remove-all-documents'?: boolean;
   'replace-id'?: boolean;
   'set-timestamps'?: boolean;
   'db-protocol'?: string;

cli/test/unit/options.ts

@@ -31,6 +31,7 @@ describe('Options', () => {
           'reconnect-timeout': 7000,
           'drop-database': true,
           'drop-collections': true,
+          'remove-all-documents': true,
           'transpile-only': true,
           'ejson-parse-canonical-mode': true,
         },
@@ -40,6 +41,7 @@ describe('Options', () => {
             databaseReconnectTimeout: 7000,
             dropDatabase: true,
             dropCollections: true,
+            removeAllDocuments: true,
           },
           cli: {
             dataPath: './foo/bar',
@@ -182,6 +184,7 @@ describe('Options', () => {
           RECONNECT_TIMEOUT: '7000',
           DROP_DATABASE: 'true',
           DROP_COLLECTIONS: 'true',
+          REMOVE_ALL_DOCUMENTS: 'true',
           TRANSPILE_ONLY: 'true',
         },
         expected: {
@@ -190,6 +193,7 @@ describe('Options', () => {
             databaseReconnectTimeout: 7000,
             dropDatabase: true,
             dropCollections: true,
+            removeAllDocuments: true,
           },
           cli: {
             transpileOnly: true,
@@ -218,6 +222,7 @@ describe('Options', () => {
             },
             dropDatabase: false,
             dropCollections: false,
+            removeAllDocuments: false,
           },
           cli: {
             transpileOnly: false,

core/src/config.ts

@@ -12,6 +12,7 @@ export interface SeederConfig {
   databaseReconnectTimeout: number; // maximum time of waiting for successful MongoDB connection in milliseconds. Ignored when `mongoClientOptions` are passed.
   dropDatabase: boolean; // drops entire database before import
   dropCollections: boolean; // drops collection before importing it
+  removeAllDocuments: boolean; // remove all documents from collections before importing it
   mongoClientOptions?: MongoClientOptions; // optional MongoDB client options
   collectionInsertManyOptions?: CollectionInsertManyOptions; // optional MongoDB collection import options
 }
@@ -24,6 +25,7 @@ export const defaultSeederConfig: SeederConfig = {
   databaseReconnectTimeout: 10000,
   dropDatabase: false,
   dropCollections: false,
+  removeAllDocuments: false,
 };
 
 /**

core/src/database/database.ts

@@ -83,6 +83,20 @@ export class Database {
     return this.db.collection(collectionName).drop();
   }
 
+  /**
+   * Remove all documents from a given collection
+   * if it exists.
+   *
+   * @param collectionName Collection name
+   */
+  async removeAllDocumentsIfCollectionExists(collectionName: string) {
+    if (!(await this.ifCollectionExist(collectionName))) {
+      return;
+    }
+
+    return this.db.collection(collectionName).deleteMany({});
+  }
+
   /**
    * Closes connection with database.
    */

core/src/index.ts

@@ -62,7 +62,11 @@ export class Seeder {
     let collections;
     try {
       const { CollectionPopulator } = require('./populator');
-      const populator = new CollectionPopulator(config.extensions, config.ejsonParseOptions, this.log);
+      const populator = new CollectionPopulator(
+        config.extensions,
+        config.ejsonParseOptions,
+        this.log,
+      );
 
       this.log(`Reading collections from ${path}...`);
       collections = populator.readFromPath(path);
@@ -104,7 +108,7 @@ export class Seeder {
       this.log,
     );
 
-    let database;
+    var database: Database | undefined;
     try {
       database = await databaseConnector.connect(config.database);
 
@@ -120,6 +124,14 @@ export class Seeder {
         await database.drop();
       }
 
+      if (config.removeAllDocuments) {
+        this.log('Removing all documents from collections...');
+        const promisses = collections.map((collection) =>
+          database!.removeAllDocumentsIfCollectionExists(collection.name),
+        );
+        await Promise.all(promisses);
+      }
+
       await new CollectionImporter(
         database,
         config.collectionInsertManyOptions,

core/test/integration/_importdata/remove-docs/import-one/test1.json

@@ -0,0 +1,4 @@
+{
+  "number": 1,
+  "name": "one"
+}

core/test/integration/database.ts

@@ -86,4 +86,50 @@ describe('Database', () => {
       expectedCollections[1],
     ]);
   });
+
+  it('should not drop any database or collection while removing all documents', async () => {
+    const expectedCollections = ['db-remove-doc-first', 'db-remove-doc-second'];
+
+    for (const collection of expectedCollections) {
+      await createCollection(database.db, collection);
+    }
+
+    await database.removeAllDocumentsIfCollectionExists(expectedCollections[0]);
+    await expect(listExistingCollections(database.db)).resolves.toStrictEqual(
+      expect.arrayContaining([expectedCollections[0], expectedCollections[1]]),
+    );
+  });
+
+  it('should remove all documents from collection without droping the db/collection', async () => {
+    const documents = [
+      {
+        value: 1,
+      },
+      {
+        name: 'two',
+        value: 2,
+      },
+      {
+        value: 3,
+        object: {
+          name: 'three',
+        },
+      },
+    ];
+    const collection = 'db-remove-docs';
+
+    await database.insertDocumentsIntoCollection(documents, collection);
+    const inserted = await database.db.collection(collection).find().toArray();
+    expect(inserted).toHaveLength(documents.length);
+
+    await database.removeAllDocumentsIfCollectionExists(collection);
+    const result = await database.db.collection(collection).find().toArray();
+    expect(result).toHaveLength(0);
+  });
+
+  it('should not crash if collection does no exists', async () => {
+    await database.removeAllDocumentsIfCollectionExists(
+      'non-existing-collection',
+    );
+  });
 });