add client timeout tests

internal/testing/delayhttp/delayhttp.go

@@ -0,0 +1,35 @@
+// Package delayhttp creates http.HandlerFunc's that delays the response.
+// Useful for testing timeout scenarios.
+package delayhttp
+
+import (
+	"net/http"
+	"time"
+)
+
+// WithChannel returns a handler that delays until it recieves something on returnChan
+func WithChannel(returnChan chan struct{}) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		// Wait until channel sends return code
+		<-returnChan
+	}
+}
+
+// WithCancel returns a handler that delays until the cancel func is called.
+// Useful together with defer to clean up tests.
+func WithCancel() (http.HandlerFunc, func()) {
+	returnChan := make(chan struct{}, 1)
+	return WithChannel(returnChan), func() {
+		returnChan <- struct{}{}
+	}
+}
+
+// WithTimeout returns a handler that delays until the passed duration has elapsed
+func WithTimeout(delay time.Duration) http.HandlerFunc {
+	returnChan := make(chan struct{}, 1)
+	go func() {
+		time.Sleep(delay)
+		returnChan <- struct{}{}
+	}()
+	return WithChannel(returnChan)
+}