send content type only if body is defined, fixes #19

Author: ajaishankar

src/fetcher.ts

@@ -72,10 +72,10 @@ function getQuery(
   return queryString(queryObj)
 }
 
-function getHeaders(init?: HeadersInit) {
+function getHeaders(body?: string, init?: HeadersInit) {
   const headers = new Headers(init)
 
-  if (!headers.has('Content-Type')) {
+  if (body !== undefined && !headers.has('Content-Type')) {
     headers.append('Content-Type', 'application/json')
   }
 
@@ -120,14 +120,15 @@ function getFetchParams(request: Request) {
 
   const path = getPath(request.path, payload)
   const query = getQuery(request.method, payload, request.queryParams)
-  const headers = getHeaders(request.init?.headers)
+  const body = getBody(request.method, payload)
+  const headers = getHeaders(body, request.init?.headers)
   const url = request.baseUrl + path + query
 
   const init = {
     ...request.init,
     method: request.method.toUpperCase(),
     headers,
-    body: getBody(request.method, payload),
+    body,
   }
 
   return { url, init }
@@ -179,7 +180,6 @@ function wrapMiddlewares(middlewares: Middleware[], fetch: Fetch): Fetch {
       return fetch(url, init)
     }
     const current = middlewares[index]
-    init = init || { headers: getHeaders() }
     return await current(url, init, (nextUrl, nextInit) =>
       handler(index + 1, nextUrl, nextInit),
     )

test/fetch.test.ts

@@ -24,10 +24,14 @@ describe('fetch', () => {
 
   const expectedHeaders = {
     authorization: 'Bearer token',
-    'content-type': 'application/json',
     accept: 'application/json',
   }
 
+  const headersWithContentType = {
+    ...expectedHeaders,
+    'content-type': 'application/json',
+  }
+
   it('GET /query/{a}/{b}', async () => {
     const fun = fetcher.path('/query/{a}/{b}').method('get').create()
 
@@ -60,7 +64,7 @@ describe('fetch', () => {
       expect(data.params).toEqual({ id: '1' })
       expect(data.body).toEqual({ list: ['b', 'c'] })
       expect(data.query).toEqual({})
-      expect(data.headers).toEqual(expectedHeaders)
+      expect(data.headers).toEqual(headersWithContentType)
     })
   })
 
@@ -73,7 +77,7 @@ describe('fetch', () => {
       expect(data.params).toEqual({ id: '1' })
       expect(data.body).toEqual(['b', 'c'])
       expect(data.query).toEqual({})
-      expect(data.headers).toEqual(expectedHeaders)
+      expect(data.headers).toEqual(headersWithContentType)
     })
   })
 
@@ -93,10 +97,20 @@ describe('fetch', () => {
       expect(data.params).toEqual({ id: '1' })
       expect(data.body).toEqual({ list: ['b', 'c'] })
       expect(data.query).toEqual({ scalar: 'a' })
-      expect(data.headers).toEqual(expectedHeaders)
+      expect(data.headers).toEqual(headersWithContentType)
     })
   })
 
+  it(`DELETE /body/{id} (empty body)`, async () => {
+    const fun = fetcher.path('/body/{id}').method('delete').create()
+
+    const { data } = await fun({ id: 1 } as any)
+
+    expect(data.params).toEqual({ id: '1' })
+    expect(data.headers).toHaveProperty('accept')
+    expect(data.headers).not.toHaveProperty('content-type')
+  })
+
   it('GET /error', async () => {
     expect.assertions(3)