test: Add test for buffer support

test/flaska.out.test.mjs

@@ -91,6 +91,38 @@ t.describe('#requestEnd()', function() {
         flaska.requestEnd(null, ctx)
       })
 
+      t.test('call res and end correctly when dealing with buffers', function(cb) {
+        const assertStatus = 202
+        // Calculated manually just in case
+        const assertBodyLength = 11
+        const assertBody = Buffer.from('hello world')
+        let onFinish = cb.finish(function(body) {
+          assert.strictEqual(ctx.status, assertStatus)
+          assert.strictEqual(ctx.body, assertBody)
+          assert.strictEqual(ctx.headers['Content-Type'], 'application/octet-stream')
+          assert.strictEqual(ctx.headers['Content-Length'], assertBodyLength)
+
+          if (method === 'GET') {
+            assert.ok(body)
+            assert.strictEqual(body, assertBody)
+          } else {
+            assert.notOk(body)
+          }
+
+          assert.ok(ctx.res.writeHead.called)
+          assert.strictEqual(ctx.res.writeHead.firstCall[0], ctx.status)
+          assert.strictEqual(ctx.res.writeHead.firstCall[1], ctx.headers)
+        })
+        const ctx = createCtx({
+          method: method,
+          status: assertStatus,
+        }, onFinish)
+        ctx.body = assertBody
+    
+        let flaska = new Flaska({}, fakerHttp, fakeStream)
+        flaska.requestEnd(null, ctx)
+      })
+
       t.test('call res and end correctly when dealing with null and no status override', function(cb) {
         // Calculated manually just in case
         const assertBodyLength = 0