test: cover leading BOM stripping in json and url-search-params bodies

packages/aws-lambda/src/body.test.ts

@@ -66,6 +66,21 @@ describe('toStandardBody', () => {
       }))).resolves.toEqual({ foo: 'bar' })
     })
 
+    it('strips a leading BOM from json', async () => {
+      await expect(toStandardBody(event({
+        body: '\uFEFF{"foo":"bar"}',
+        multiValueHeaders: { 'Content-Type': ['application/json'] },
+      }))).resolves.toEqual({ foo: 'bar' })
+    })
+
+    it('strips a leading BOM from base64-encoded json', async () => {
+      await expect(toStandardBody(event({
+        body: Buffer.from('\uFEFF{"foo":"bar"}').toString('base64'),
+        isBase64Encoded: true,
+        multiValueHeaders: { 'Content-Type': ['application/json'] },
+      }))).resolves.toEqual({ foo: 'bar' })
+    })
+
     it('parses empty json as undefined', async () => {
       await expect(toStandardBody(event({
         body: '',
@@ -81,6 +96,13 @@ describe('toStandardBody', () => {
         multiValueHeaders: { 'Content-Type': ['application/x-www-form-urlencoded'] },
       }))).resolves.toEqual(new URLSearchParams('foo=bar&baz=qux'))
     })
+
+    it('strips a leading BOM from url-encoded forms', async () => {
+      await expect(toStandardBody(event({
+        body: '\uFEFFfoo=bar',
+        multiValueHeaders: { 'Content-Type': ['application/x-www-form-urlencoded'] },
+      }))).resolves.toEqual(new URLSearchParams('foo=bar'))
+    })
   })
 
   describe('form-data', () => {

packages/fetch/src/body.test.ts

@@ -73,6 +73,18 @@ describe('toStandardBody', () => {
       expect(await toStandardBody(request)).toEqual({ foo: 'bar' })
     })
 
+    it('json strips a leading BOM', async () => {
+      const request = new Request('https://example.com', {
+        method: 'POST',
+        body: '\uFEFF{"foo":"bar"}',
+        headers: {
+          'standard-server': 'json',
+        },
+      })
+
+      expect(await toStandardBody(request)).toEqual({ foo: 'bar' })
+    })
+
     it('async iterator object', async () => {
       const stream = new ReadableStream<string>({
         async pull(controller) {
@@ -130,6 +142,18 @@ describe('toStandardBody', () => {
       expect(await toStandardBody(request)).toEqual(new URLSearchParams('foo=bar&bar=baz'))
     })
 
+    it('url-search-params strips a leading BOM', async () => {
+      const request = new Request('https://example.com', {
+        method: 'POST',
+        body: '\uFEFFfoo=bar',
+        headers: {
+          'standard-server': 'url-search-params',
+        },
+      })
+
+      expect(await toStandardBody(request)).toEqual(new URLSearchParams('foo=bar'))
+    })
+
     it('file/blob', async () => {
       const request = new Request('https://example.com', {
         method: 'POST',

packages/node/src/body.test.ts

@@ -86,6 +86,20 @@ describe('toStandardBody', () => {
       expect(standardBody).toEqual({ foo: 'bar' })
     })
 
+    it('json strips a leading BOM', async () => {
+      let standardBody: StandardBody = {} as any
+
+      await request(async (req: IncomingMessage, res: ServerResponse) => {
+        standardBody = await toStandardBody(req)
+        res.end()
+      })
+        .post('/')
+        .set('standard-server', 'json')
+        .send('\uFEFF{"foo":"bar"}')
+
+      expect(standardBody).toEqual({ foo: 'bar' })
+    })
+
     it('async iterator object', async () => {
       let standardBody: any
 
@@ -133,6 +147,20 @@ describe('toStandardBody', () => {
       expect(standardBody).toEqual(new URLSearchParams('foo=bar&bar=baz'))
     })
 
+    it('url-search-params strips a leading BOM', async () => {
+      let standardBody: any
+
+      await request(async (req: IncomingMessage, res: ServerResponse) => {
+        standardBody = await toStandardBody(req)
+        res.end()
+      })
+        .post('/')
+        .set('standard-server', 'url-search-params')
+        .send('\uFEFFfoo=bar')
+
+      expect(standardBody).toEqual(new URLSearchParams('foo=bar'))
+    })
+
     it('file/blob', async () => {
       let standardBody: any