fix: only parse response if it has content

Author: coderbyheart

src/REST.spec.ts

@@ -26,6 +26,7 @@ void describe('REST', () => {
 				},
 				{
 					'content-type': 'application/json; charset=utf-8',
+					'content-length': '42',
 				},
 			)
 
@@ -44,6 +45,7 @@ void describe('REST', () => {
 				},
 				{
 					'content-type': 'application/json; charset=utf-8',
+					'content-length': '42',
 				},
 			)
 

src/lib/doRequest.spec.ts

@@ -9,6 +9,7 @@ void describe('doRequest()', () => {
 				status: 200,
 				headers: new Map<string, string>([
 					['content-type', 'application/json'],
+					['content-length', '42'],
 				]),
 				json: async () => Promise.resolve({ foo: 'bar' }),
 			}),
@@ -37,6 +38,34 @@ void describe('doRequest()', () => {
 		})
 	})
 
+	void it('should only parse the response if there is content', async () => {
+		const mockFetch = mock.fn(async () =>
+			Promise.resolve({
+				status: 200,
+				headers: new Map<string, string>([
+					['content-type', 'application/json'],
+					['content-length', '0'],
+				]),
+				json: async () => Promise.resolve(JSON.parse('')), // Intentional empty JSON
+			}),
+		)
+		const assertFn = mock.fn<AssertFn>(async () => Promise.resolve())
+
+		const inFlight = doRequest(
+			new URL('https://example.com'),
+			{
+				method: 'POST',
+			},
+			undefined,
+			mockFetch as any,
+		)
+
+		await inFlight.match(assertFn)
+		assert.partialDeepStrictEqual(assertFn.mock.calls[0]?.arguments?.[0], {
+			body: undefined,
+		})
+	})
+
 	void it('should retry the request if the assert fails', async () => {
 		const mockFetch = mock.fn<() => Promise<ReturnType<typeof fetch>>>()
 		mockFetch.mock.mockImplementationOnce(
@@ -53,6 +82,7 @@ void describe('doRequest()', () => {
 					status: 200,
 					headers: new Map<string, string>([
 						['content-type', 'application/json'],
+						['content-length', '42'],
 					]),
 					json: async () => Promise.resolve({ foo: 'bar' }),
 				} as any),

src/lib/doRequest.ts

@@ -35,7 +35,10 @@ export const doRequest = (
 		for (const [k, v] of res.headers.entries()) {
 			logger?.progress(`< ${k}: ${v}`)
 		}
-		if (res.headers.get('content-type')?.includes('json') ?? false) {
+		if (
+			(res.headers.get('content-type')?.includes('json') ?? false) &&
+			parseInt(res.headers.get('content-length') ?? '0', 10) > 1
+		) {
 			const responseBody = await res.json()
 			logger?.progress(`< ${JSON.stringify(responseBody)}`)
 			return {