Refactor usages of Node.js Buffer (#1650)

* [wip]

* Passes tests, uploads files

* Clean up

* instanceof Uint8Array in flattenAndStringify

* Add webhook test

* reviewer comments pt. 1

* Add tests for Uint8Array

* add type to push(l)

* Reviewer comments round 2

* Update WebhookHeader and WebhookPayload types

src/Error.ts

@@ -128,10 +128,14 @@ class StripeConnectionError extends StripeError {}
  * webhook fails
  */
 class StripeSignatureVerificationError extends StripeError {
-  header: string;
-  payload: string;
-
-  constructor(header: string, payload: string, raw: StripeRawError = {}) {
+  header: string | Uint8Array;
+  payload: string | Uint8Array;
+
+  constructor(
+    header: string | Uint8Array,
+    payload: string | Uint8Array,
+    raw: StripeRawError = {}
+  ) {
     super(raw);
     this.header = header;
     this.payload = payload;

src/Types.d.ts

@@ -1,6 +1,6 @@
 /* eslint-disable camelcase */
 type AppInfo = {name?: string} & Record<string, unknown>;
-type BufferedFile = {name: string; type: string; file: {data: Buffer}};
+type BufferedFile = {name: string; type: string; file: {data: Uint8Array}};
 type HttpClientResponseError = {code: number};
 type HttpHeaderValue = string | number | string[];
 type MethodSpec = {

src/Webhooks.ts

@@ -2,15 +2,15 @@ import utils = require('./utils');
 import _Error = require('./Error');
 const {StripeError, StripeSignatureVerificationError} = _Error;
 
-type WebhookHeader = string | Buffer;
+type WebhookHeader = string | Uint8Array;
 type WebhookParsedHeader = {
   signatures: Array<string>;
   timestamp: number;
 };
 type WebhookParsedEvent = {
   details: WebhookParsedHeader;
-  decodedPayload: string;
-  decodedHeader: string;
+  decodedPayload: WebhookHeader;
+  decodedHeader: WebhookPayload;
 };
 type WebhookTestHeaderOptions = {
   timestamp: number;
@@ -22,7 +22,7 @@ type WebhookTestHeaderOptions = {
 };
 
 type WebhookEvent = Record<string, unknown>;
-type WebhookPayload = string | Buffer;
+type WebhookPayload = string | Uint8Array;
 type WebhookSignatureObject = {
   verifyHeader: (
     encodedPayload: WebhookPayload,
@@ -78,8 +78,10 @@ const Webhook: WebhookObject = {
       cryptoProvider
     );
 
-    // @ts-ignore
-    const jsonPayload = JSON.parse(payload);
+    const jsonPayload =
+      payload instanceof Uint8Array
+        ? JSON.parse(new TextDecoder('utf8').decode(payload))
+        : JSON.parse(payload);
     return jsonPayload;
   },
 
@@ -98,8 +100,10 @@ const Webhook: WebhookObject = {
       cryptoProvider
     );
 
-    // @ts-ignore
-    const jsonPayload = JSON.parse(payload);
+    const jsonPayload =
+      payload instanceof Uint8Array
+        ? JSON.parse(new TextDecoder('utf8').decode(payload))
+        : JSON.parse(payload);
     return jsonPayload;
   },
 
@@ -218,9 +222,11 @@ function parseEventDetails(
   encodedHeader: WebhookHeader,
   expectedScheme: string
 ): WebhookParsedEvent {
-  const decodedPayload = Buffer.isBuffer(encodedPayload)
-    ? encodedPayload.toString('utf8')
-    : encodedPayload;
+  const textDecoder = new TextDecoder('utf8');
+  const decodedPayload =
+    encodedPayload instanceof Uint8Array
+      ? textDecoder.decode(encodedPayload)
+      : encodedPayload;
 
   // Express's type for `Request#headers` is `string | []string`
   // which is because the `set-cookie` header is an array,
@@ -232,9 +238,10 @@ function parseEventDetails(
     );
   }
 
-  const decodedHeader = Buffer.isBuffer(encodedHeader)
-    ? encodedHeader.toString('utf8')
-    : encodedHeader;
+  const decodedHeader =
+    encodedHeader instanceof Uint8Array
+      ? textDecoder.decode(encodedHeader)
+      : encodedHeader;
 
   const details = parseHeader(decodedHeader, expectedScheme);
 
@@ -259,7 +266,7 @@ function parseEventDetails(
 
 function validateComputedSignature(
   payload: WebhookPayload,
-  header: string,
+  header: WebhookHeader,
   details: WebhookParsedHeader,
   expectedSignature: string,
   tolerance: number
@@ -292,7 +299,7 @@ function validateComputedSignature(
 }
 
 function parseHeader(
-  header: string,
+  header: WebhookHeader,
   scheme: string
 ): WebhookParsedHeader | null {
   if (typeof header !== 'string') {

src/multipart.ts

@@ -6,7 +6,7 @@ class StreamProcessingError extends StripeError {}
 type MultipartCallbackReturn = any;
 type MultipartCallback = (
   error: Error | null,
-  data: Buffer | string | null
+  data: Uint8Array | string | null
 ) => MultipartCallbackReturn;
 // Method for formatting HTTP body for the multipart/form-data specification
 // Mostly taken from Fermata.js
@@ -15,20 +15,25 @@ const multipartDataGenerator = (
   method: string,
   data: MultipartRequestData,
   headers: RequestHeaders
-): Buffer => {
+): Uint8Array => {
   const segno = (
     Math.round(Math.random() * 1e16) + Math.round(Math.random() * 1e16)
   ).toString();
   headers['Content-Type'] = `multipart/form-data; boundary=${segno}`;
-  let buffer = Buffer.alloc(0);
+  const textEncoder = new TextEncoder();
 
-  function push(l: any): void {
+  let buffer = new Uint8Array(0);
+  const endBuffer = textEncoder.encode('\r\n');
+
+  function push(l: string | Uint8Array): void {
     const prevBuffer = buffer;
-    const newBuffer = l instanceof Buffer ? l : Buffer.from(l);
-    buffer = Buffer.alloc(prevBuffer.length + newBuffer.length + 2);
-    prevBuffer.copy(buffer);
-    newBuffer.copy(buffer, prevBuffer.length);
-    buffer.write('\r\n', buffer.length - 2);
+    const newBuffer =
+      l instanceof Uint8Array ? l : new Uint8Array(textEncoder.encode(l));
+    buffer = new Uint8Array(prevBuffer.length + newBuffer.length + 2);
+
+    buffer.set(prevBuffer);
+    buffer.set(newBuffer, prevBuffer.length);
+    buffer.set(endBuffer, buffer.length - 2);
   }
 
   function q(s: string): string {
@@ -43,7 +48,7 @@ const multipartDataGenerator = (
     if (Object.prototype.hasOwnProperty.call(v, 'data')) {
       const typedEntry: {
         name: string;
-        data: BufferedFile;
+        data: string | Uint8Array;
         type: string;
       } = v as any;
       push(
@@ -71,15 +76,15 @@ const streamProcessor = (
   headers: RequestHeaders,
   callback: MultipartCallback
 ): void => {
-  const bufferArray: Array<Buffer> = [];
+  const bufferArray: Array<Uint8Array> = [];
   data.file.data
-    .on('data', (line: Buffer) => {
+    .on('data', (line: Uint8Array) => {
       bufferArray.push(line);
     })
     .once('end', () => {
       // @ts-ignore
       const bufferData: BufferedFile = Object.assign({}, data);
-      bufferData.file.data = Buffer.concat(bufferArray);
+      bufferData.file.data = utils.concat(bufferArray);
       const buffer = multipartDataGenerator(method, bufferData, headers);
       callback(null, buffer);
     })