fix: Content-Length with UTF-8 2-byte characters

Author: bogeychan

.vscode/launch.json

@@ -0,0 +1,18 @@
+{
+    "configurations": [
+        {
+            // based on https://tsx.is/vscode
+            "name": "Debug file with tsx",
+            "type": "node",
+            "request": "launch",
+            "program": "${file}",
+            "runtimeExecutable": "tsx",
+            "console": "integratedTerminal",
+            "internalConsoleOptions": "neverOpen",
+            "skipFiles": [
+                "<node_internals>/**",
+                "${workspaceFolder}/node_modules/**",
+            ],
+        }
+    ]
+}

src/handler.ts

@@ -263,7 +263,10 @@ export const mapResponse = (
 			set.headers['content-type'] = 'text/plain;charset=utf8'
 
 			if (res) {
-				set.headers['content-length'] = (response as string).length
+				set.headers['content-length'] = Buffer.byteLength(
+					response as string,
+					'utf8'
+				)
 				res.writeHead(set.status!, set.headers)
 				res.end(response)
 			}
@@ -275,7 +278,10 @@ export const mapResponse = (
 			response = JSON.stringify(response)
 
 			set.headers['content-type'] = 'application/json;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -349,7 +355,10 @@ export const mapResponse = (
 			response = JSON.stringify(response)
 
 			set.headers['content-type'] = 'application/json;charset=utf8'
-			set.headers['content-length'] = (response as string)?.length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -392,7 +401,10 @@ export const mapResponse = (
 			response = (response as number | boolean).toString()
 
 			set.headers['content-type'] = 'text/plain;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -474,7 +486,10 @@ export const mapResponse = (
 							'application/json;charset=utf8'
 
 					response = JSON.stringify(response)
-					set.headers['content-length'] = (response as string).length
+					set.headers['content-length'] = Buffer.byteLength(
+						response as string,
+						'utf8'
+					)
 
 					if (res) {
 						res.writeHead(set.status!, set.headers)
@@ -486,7 +501,10 @@ export const mapResponse = (
 			}
 
 			set.headers['content-type'] = 'text/plain;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -517,7 +535,10 @@ export const mapEarlyResponse = (
 	switch (response?.constructor?.name) {
 		case 'String':
 			set.headers['content-type'] = 'text/plain;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -531,7 +552,10 @@ export const mapEarlyResponse = (
 			response = JSON.stringify(response)
 
 			set.headers['content-type'] = 'application/json;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -599,7 +623,10 @@ export const mapEarlyResponse = (
 			response = JSON.stringify(response)
 
 			set.headers['content-type'] = 'application/json;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			return [response, set as any]
 
@@ -637,7 +664,10 @@ export const mapEarlyResponse = (
 			response = (response as number | boolean).toString()
 
 			set.headers['content-type'] = 'text/plain;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)
@@ -716,7 +746,10 @@ export const mapEarlyResponse = (
 					if (!set.headers['Content-Type'])
 						set.headers['content-type'] =
 							'application/json;charset=utf8'
-					set.headers['content-length'] = (response as string).length
+					set.headers['content-length'] = Buffer.byteLength(
+						response as string,
+						'utf8'
+					)
 
 					if (res) {
 						res.writeHead(set.status!, set.headers)
@@ -728,7 +761,10 @@ export const mapEarlyResponse = (
 			}
 
 			set.headers['content-type'] = 'text/plain;charset=utf8'
-			set.headers['content-length'] = (response as string).length
+			set.headers['content-length'] = Buffer.byteLength(
+				response as string,
+				'utf8'
+			)
 
 			if (res) {
 				res.writeHead(set.status!, set.headers)

test/core/charset.test.ts

@@ -0,0 +1,30 @@
+import Elysia from 'elysia'
+import { inject } from 'light-my-request'
+import { describe, it, expect } from 'vitest'
+
+import node from '../../src'
+
+const app = new Elysia({ adapter: node() })
+	.get('/', () => ({ utf: 'ú' }))
+	.compile()
+
+// @ts-expect-error
+const handle = app._handle!
+
+describe('Node - Charset', () => {
+	it('handle UTF-8 2-byte characters', () => {
+		inject(handle, { path: '/' }, (error, res) => {
+			expect(error).toBeNull()
+
+			const expected = JSON.stringify({ utf: 'ú' })
+
+			expect(res?.body).toBe(expected)
+			expect(res?.headers['content-type']).toBe(
+				'application/json;charset=utf8'
+			)
+			expect(res?.headers['content-length']).toBe(
+				new TextEncoder().encode(expected).byteLength.toString()
+			)
+		})
+	})
+})