Add test to expose interface upgrade bug

In principle, we needed to iterate through all permutations, mirroring
the same that is happening in the code. For lack of time, I only
picked one of the cases currently buggy.

As said, this really needs code generation, should we ever find
ourselves touching this again.
This commit is contained in:
beorn7 2018-02-02 15:50:46 +01:00
parent ebe4271dac
commit d892fd2b51
1 changed files with 26 additions and 0 deletions

View File

@ -281,6 +281,16 @@ func (t *testResponseWriter) ReadFrom(io.Reader) (int64, error) {
return 0, nil return 0, nil
} }
// testFlusher is an http.ResponseWriter that also implements http.Flusher.
type testFlusher struct {
flushCalled bool
}
func (t *testFlusher) Header() http.Header { return nil }
func (t *testFlusher) Write([]byte) (int, error) { return 0, nil }
func (t *testFlusher) WriteHeader(int) {}
func (t *testFlusher) Flush() { t.flushCalled = true }
func TestInterfaceUpgrade(t *testing.T) { func TestInterfaceUpgrade(t *testing.T) {
w := &testResponseWriter{} w := &testResponseWriter{}
d := newDelegator(w, nil) d := newDelegator(w, nil)
@ -299,6 +309,22 @@ func TestInterfaceUpgrade(t *testing.T) {
if _, ok := d.(http.Hijacker); ok { if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker") t.Error("delegator unexpectedly implements http.Hijacker")
} }
f := &testFlusher{}
d = newDelegator(f, nil)
if _, ok := d.(http.CloseNotifier); ok {
t.Error("delegator unexpectedly implements http.CloseNotifier")
}
d.(http.Flusher).Flush()
if !w.flushCalled {
t.Error("Flush not called")
}
if _, ok := d.(io.ReaderFrom); ok {
t.Error("delegator unexpectedly implements io.ReaderFrom")
}
if _, ok := d.(http.Hijacker); ok {
t.Error("delegator unexpectedly implements http.Hijacker")
}
} }
func ExampleInstrumentHandlerDuration() { func ExampleInstrumentHandlerDuration() {