feat: adds stream to tsv file writer

src/cli/commands/generate.command.ts

@@ -1,10 +1,11 @@
 import got from 'got';
-import { appendFile } from 'node:fs/promises';
 
 import { ICommand } from './types/command.interface.js';
 import { DECIMAL_RADIX } from '../../shared/constants/decimal-radix.const.js';
 import { IMockServerData } from '../../shared/types/mock-server-data.interface.js';
 import { TSVOfferGenerator } from '../../shared/libs/offer-generator/tsv-offer-generator.js';
+import { getErrorMessage } from '../../shared/utils/getErrorMessage.js';
+import { TSVFileWriter } from '../../shared/libs/file-writer/index.js';
 
 export class GenerateCommand implements ICommand {
   private initialData: IMockServerData;
@@ -19,8 +20,10 @@ export class GenerateCommand implements ICommand {
 
   private async write(filePath: string, offersQuantity: number) {
     const tsvOfferGenerator = new TSVOfferGenerator(this.initialData);
+    const tsvFileWriter = new TSVFileWriter(filePath);
+
     for (let i = 0; i < offersQuantity; i++) {
-      await appendFile(filePath, `${tsvOfferGenerator.generate()}\n`, { encoding: 'utf8' });
+      await tsvFileWriter.write(tsvOfferGenerator.generate());
     }
   }
 
@@ -38,10 +41,7 @@ export class GenerateCommand implements ICommand {
       console.info(`File ${filePath} was created!`);
     } catch (error: unknown) {
       console.error('Can\'t generate data');
-
-      if (error instanceof Error) {
-        console.error(error.message);
-      }
+      console.error(getErrorMessage(error));
     }
   }
 }

src/shared/libs/file-writer/index.ts

@@ -0,0 +1 @@
+export { TSVFileWriter } from './tsv-file-writer.js';

src/shared/libs/file-writer/tsv-file-writer.ts

@@ -0,0 +1,26 @@
+import { IFileWriter } from './types/file-writer.interface.js';
+import { WriteStream, createWriteStream } from 'node:fs';
+
+export class TSVFileWriter implements IFileWriter {
+  private readonly stream: WriteStream;
+
+  constructor(fileName: string) {
+    this.stream = createWriteStream(fileName, {
+      flags: 'w',
+      encoding: 'utf-8',
+      autoClose: true,
+    });
+  }
+
+  public async write(row: string): Promise<void> {
+    const writeSuccess = this.stream.write(`${row}\n`);
+
+    if (!writeSuccess) {
+      return new Promise<void>((resolve) => {
+        this.stream.once('drain',() => resolve());
+      });
+    }
+
+    return Promise.resolve();
+  }
+}

src/shared/libs/file-writer/types/file-writer.interface.ts

@@ -0,0 +1,3 @@
+export interface IFileWriter {
+  write(row: string): Promise<void>;
+}