Rewrite 'parseBody' to use async/await

src/parseBody.js

@@ -21,67 +21,56 @@ import type { $Request } from 'express';
  * Provided a "Request" provided by express or connect (typically a node style
  * HTTPClientRequest), Promise the body data contained.
  */
-export function parseBody(req: $Request): Promise<{ [param: string]: mixed }> {
- return new Promise((resolve, reject) => {
- const body = req.body;
-
- // If express has already parsed a body as a keyed object, use it.
- if (typeof body === 'object' && !(body instanceof Buffer)) {
- return resolve((body: any));
- }
-
- // Skip requests without content types.
- if (req.headers['content-type'] === undefined) {
- return resolve({});
- }
-
- const typeInfo = contentType.parse(req);
-
- // If express has already parsed a body as a string, and the content-type
- // was application/graphql, parse the string body.
- if (typeof body === 'string' && typeInfo.type === 'application/graphql') {
- return resolve(graphqlParser(body));
- }
-
- // Already parsed body we didn't recognise? Parse nothing.
- if (body) {
- return resolve({});
- }
-
- // Use the correct body parser based on Content-Type header.
- switch (typeInfo.type) {
- case 'application/graphql':
- return read(req, typeInfo, graphqlParser, resolve, reject);
- case 'application/json':
- return read(req, typeInfo, jsonEncodedParser, resolve, reject);
- case 'application/x-www-form-urlencoded':
- return read(req, typeInfo, urlEncodedParser, resolve, reject);
- }
-
- // If no Content-Type header matches, parse nothing.
- return resolve({});
- });
-}
+export async function parseBody(
+ req: $Request,
+): Promise<{ [param: string]: mixed }> {
+ const body = req.body;
+
+ // If express has already parsed a body as a keyed object, use it.
+ if (typeof body === 'object' && !(body instanceof Buffer)) {
+ return (body: any);
+ }
 
-function jsonEncodedParser(body) {
- if (jsonObjRegex.test(body)) {
- /* eslint-disable no-empty */
- try {
- return JSON.parse(body);
- } catch (error) {
- // Do nothing
- }
- /* eslint-enable no-empty */
+ // Skip requests without content types.
+ if (req.headers['content-type'] === undefined) {
+ return {};
  }
- throw httpError(400, 'POST body sent invalid JSON.');
-}
 
-function urlEncodedParser(body) {
- return querystring.parse(body);
-}
+ const typeInfo = contentType.parse(req);
+
+ // If express has already parsed a body as a string, and the content-type
+ // was application/graphql, parse the string body.
+ if (typeof body === 'string' && typeInfo.type === 'application/graphql') {
+ return { query: body };
+ }
 
-function graphqlParser(body) {
- return { query: body };
+ // Already parsed body we didn't recognise? Parse nothing.
+ if (body) {
+ return {};
+ }
+
+ const rawBody = await readBody(req, typeInfo);
+ // Use the correct body parser based on Content-Type header.
+ switch (typeInfo.type) {
+ case 'application/graphql':
+ return { query: rawBody };
+ case 'application/json':
+ if (jsonObjRegex.test(rawBody)) {
+ /* eslint-disable no-empty */
+ try {
+ return JSON.parse(rawBody);
+ } catch (error) {
+ // Do nothing
+ }
+ /* eslint-enable no-empty */
+ }
+ throw httpError(400, 'POST body sent invalid JSON.');
+ case 'application/x-www-form-urlencoded':
+ return querystring.parse(rawBody);
+ }
+
+ // If no Content-Type header matches, parse nothing.
+ return {};
 }
 
 /**
@@ -96,7 +85,7 @@ function graphqlParser(body) {
 const jsonObjRegex = /^[\x20\x09\x0a\x0d]*\{/;
 
 // Read and parse a request body.
-function read(req, typeInfo, parseFn, resolve, reject) {
+async function readBody(req, typeInfo) {
  const charset = (typeInfo.parameters.charset || 'utf-8').toLowerCase();
 
  // Assert charset encoding per JSON RFC 7159 sec 8.1
@@ -115,22 +104,13 @@ function read(req, typeInfo, parseFn, resolve, reject) {
  const stream = decompressed(req, encoding);
 
  // Read body from stream.
- getBody(stream, { encoding: charset, length, limit }, (err, body) => {
- if (err) {
- return reject(
- err.type === 'encoding.unsupported'
- ? httpError(415, `Unsupported charset "${charset.toUpperCase()}".`)
- : httpError(400, `Invalid body: ${err.message}.`),
- );
- }
-
- try {
- // Decode and parse body.
- return resolve(parseFn(body));
- } catch (error) {
- return reject(error);
- }
- });
+ try {
+ return await getBody(stream, { encoding: charset, length, limit });
+ } catch (err) {
+ throw err.type === 'encoding.unsupported'
+ ? httpError(415, `Unsupported charset "${charset.toUpperCase()}".`)
+ : httpError(400, `Invalid body: ${err.message}.`);
+ }
 }
 
 // Return a decompressed stream, given an encoding.