Throw error when stream is not defined

lib/error.ts

@@ -0,0 +1 @@
+export class InvalidStreamError extends Error {}

lib/stream-to-buffer.ts

@@ -1,11 +1,16 @@
 import { BufferableStream } from './buffer-stream';
+import { InvalidStreamError } from './error';
 
 /**
  * @Method: Returns the content of the readable stream as a buffer
  * @Param {NodeJS.ReadableStream}
  * @Return {Promise<Buffer>}
  */
 export async function streamToBuffer(stream: NodeJS.ReadableStream): Promise<Buffer> {
+    if (!stream) {
+        throw new InvalidStreamError('stream is not defined');
+    }
+
     const bufferableStream = new BufferableStream();
 
     return new Promise((resolve: (data: Buffer) => void, reject: (error: Error) => void): void => {

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@jorgeferrero/stream-to-buffer",
-    "version": "2.0.5",
+    "version": "2.0.6",
     "description": "A promise based npm package that converts a node.js ReadStream to buffer",
     "main": "dist/index.js",
     "types": "dist/index.d.ts",

test/stream-to-buffer.test.ts

@@ -4,12 +4,24 @@ import { Readable } from 'stream';
 import { streamToBuffer } from '../lib/stream-to-buffer';
 
 describe('streamToBuffer', (): void => {
+    const mockValue = (value: any): any => value;
+
     it('should return the read stream content as a Buffer', async (): Promise<void> => {
         const testData = Buffer.from('test_data');
 
         await expect(streamToBuffer(fs.createReadStream('testdata/small-file'))).resolves.toEqual(testData);
     });
 
+    it('should throw an error when the stream is not defined', async (): Promise<void> => {
+        const stream = mockValue(undefined);
+        await expect(streamToBuffer(stream)).rejects.toThrow('stream is not defined');
+    });
+
+    it('should throw an error when the stream is null', async (): Promise<void> => {
+        const stream = mockValue(null);
+        await expect(streamToBuffer(stream)).rejects.toThrow('stream is not defined');
+    });
+
     it('should throw an error when the error event is emitted', async (): Promise<void> => {
         const fakeError = new Error('fake');
         const readStream = new Readable({