http-add-on/interceptor/middleware_test.go

126 lines
3.3 KiB
Go

package main
import (
"context"
"fmt"
"math"
"net/http"
"net/http/httptest"
"testing"
"time"
"github.com/go-logr/logr"
"github.com/kedacore/http-add-on/pkg/queue"
"github.com/stretchr/testify/require"
"golang.org/x/sync/errgroup"
)
func TestCountMiddleware(t *testing.T) {
ctx := context.Background()
const host = "testingkeda.com"
r := require.New(t)
queueCounter := queue.NewFakeCounter()
middleware := countMiddleware(
logr.Discard(),
queueCounter,
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
w.Write([]byte("OK"))
}),
)
// no host in the request
req, err := http.NewRequest("GET", "/something", nil)
r.NoError(err)
agg, respRecorder := expectResizes(
ctx,
t,
0,
middleware,
req,
queueCounter,
func(t *testing.T, hostAndCount queue.HostAndCount) {},
)
r.Equal(400, respRecorder.Code)
r.Equal("Host not found, not forwarding request", respRecorder.Body.String())
r.Equal(0, agg)
// run middleware with the host in the request
req, err = http.NewRequest("GET", "/something", nil)
r.NoError(err)
req.Host = host
// for a valid request, we expect the queue to be resized twice.
// once to mark a pending HTTP request, then a second time to remove it.
// by the end of both sends, resize1 + resize2 should be 0,
// or in other words, the queue size should be back to zero
agg, respRecorder = expectResizes(
ctx,
t,
2,
middleware,
req,
queueCounter,
func(t *testing.T, hostAndCount queue.HostAndCount) {
t.Helper()
r := require.New(t)
r.Equal(float64(1), math.Abs(float64(hostAndCount.Count)))
r.Equal(host, hostAndCount.Host)
},
)
r.Equal(200, respRecorder.Code)
r.Equal("OK", respRecorder.Body.String())
r.Equal(0, agg)
}
// expectResizes creates a new httptest.ResponseRecorder, then passes req through
// the middleware. every time the middleware calls fakeCounter.Resize(), it calls
// resizeCheckFn with t and the queue.HostCount that represents the resize call
// that was made. it also maintains an aggregate delta of the counts passed to
// Resize. If, for example, the following integers were passed to resize over
// 4 calls: [-1, 1, 1, 2], the aggregate would be -1+1+1+2=3
//
// this function returns the aggregate and the httptest.ResponseRecorder that was
// created and used with the middleware
func expectResizes(
ctx context.Context,
t *testing.T,
nResizes int,
middleware http.Handler,
req *http.Request,
fakeCounter *queue.FakeCounter,
resizeCheckFn func(*testing.T, queue.HostAndCount),
) (int, *httptest.ResponseRecorder) {
t.Helper()
r := require.New(t)
const timeout = 1 * time.Second
ctx, cancel := context.WithTimeout(ctx, 1*time.Second)
defer cancel()
grp, ctx := errgroup.WithContext(ctx)
agg := 0
grp.Go(func() error {
// we expect the queue to be resized nResizes times
for i := 0; i < nResizes; i++ {
select {
case hostAndCount := <-fakeCounter.ResizedCh:
agg += hostAndCount.Count
resizeCheckFn(t, hostAndCount)
case <-ctx.Done():
return fmt.Errorf(
"timed out waiting for the count middleware. expected %d resizes, timeout was %s, iteration %d",
nResizes,
timeout,
i,
)
}
}
return nil
})
respRecorder := httptest.NewRecorder()
middleware.ServeHTTP(respRecorder, req)
r.NoError(grp.Wait())
return agg, respRecorder
}