Migrate some selection policy tests over to v2

4 files changed, 272 insertions, 360 deletions

diff --git a/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go b/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
index 66779e4..91039c9 100644
--- a/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
+++ b/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
@@ -55,7 +55,7 @@ type Transport struct {
 	// PATH_INFO for the CGI script to use.
 	SplitPath string `json:"split_path,omitempty"`
 
-	// Environment Variables
+	// Environment variables (TODO: make a map of string to value...?)
 	EnvVars [][2]string `json:"env,omitempty"`
 
 	// The duration used to set a deadline when connecting to an upstream.
diff --git a/modules/caddyhttp/reverseproxy/hosts.go b/modules/caddyhttp/reverseproxy/hosts.go
index ad27625..1c0fae3 100644
--- a/modules/caddyhttp/reverseproxy/hosts.go
+++ b/modules/caddyhttp/reverseproxy/hosts.go
@@ -34,19 +34,21 @@ type Host interface {
 	// Unhealthy returns true if the backend is unhealthy.
 	Unhealthy() bool
 
-	// CountRequest counts the given number of requests
-	// as currently in process with the host. The count
-	// should not go below 0.
+	// CountRequest atomically counts the given number of
+	// requests as currently in process with the host. The
+	// count should not go below 0.
 	CountRequest(int) error
 
-	// CountFail counts the given number of failures
-	// with the host. The count should not go below 0.
+	// CountFail atomically counts the given number of
+	// failures with the host. The count should not go
+	// below 0.
 	CountFail(int) error
 
-	// SetHealthy marks the host as either healthy (true)
-	// or unhealthy (false). If the given status is the
-	// same, this should be a no-op. It returns true if
-	// the given status was different, false otherwise.
+	// SetHealthy atomically marks the host as either
+	// healthy (true) or unhealthy (false). If the given
+	// status is the same, this should be a no-op and
+	// return false. It returns true if the status was
+	// changed; i.e. if it is now different from before.
 	SetHealthy(bool) (bool, error)
 }
 
diff --git a/modules/caddyhttp/reverseproxy/selectionpolicies.go b/modules/caddyhttp/reverseproxy/selectionpolicies.go
index 9680583..5bb2d62 100644
--- a/modules/caddyhttp/reverseproxy/selectionpolicies.go
+++ b/modules/caddyhttp/reverseproxy/selectionpolicies.go
@@ -82,7 +82,7 @@ type RandomChoiceSelection struct {
 // CaddyModule returns the Caddy module information.
 func (RandomChoiceSelection) CaddyModule() caddy.ModuleInfo {
 	return caddy.ModuleInfo{
-		Name: "http.handlers.reverse_proxy.selection_policies.random_choice",
+		Name: "http.handlers.reverse_proxy.selection_policies.random_choose",
 		New:  func() caddy.Module { return new(RandomChoiceSelection) },
 	}
 }
@@ -147,14 +147,14 @@ func (LeastConnSelection) CaddyModule() caddy.ModuleInfo {
 func (LeastConnSelection) Select(pool UpstreamPool, _ *http.Request) *Upstream {
 	var bestHost *Upstream
 	var count int
-	var leastReqs int
+	leastReqs := -1
 
 	for _, host := range pool {
 		if !host.Available() {
 			continue
 		}
 		numReqs := host.NumRequests()
-		if numReqs < leastReqs {
+		if leastReqs == -1 || numReqs < leastReqs {
 			leastReqs = numReqs
 			count = 0
 		}
diff --git a/modules/caddyhttp/reverseproxy/selectionpolicies_test.go b/modules/caddyhttp/reverseproxy/selectionpolicies_test.go
index 8006fb1..e9939d6 100644
--- a/modules/caddyhttp/reverseproxy/selectionpolicies_test.go
+++ b/modules/caddyhttp/reverseproxy/selectionpolicies_test.go
@@ -14,350 +14,260 @@
 
 package reverseproxy
 
-// TODO: finish migrating these
-
-// import (
-// 	"net/http"
-// 	"net/http/httptest"
-// 	"os"
-// 	"testing"
-// )
-
-// var workableServer *httptest.Server
-
-// func TestMain(m *testing.M) {
-// 	workableServer = httptest.NewServer(http.HandlerFunc(
-// 		func(w http.ResponseWriter, r *http.Request) {
-// 			// do nothing
-// 		}))
-// 	r := m.Run()
-// 	workableServer.Close()
-// 	os.Exit(r)
-// }
-
-// type customPolicy struct{}
-
-// func (customPolicy) Select(pool HostPool, _ *http.Request) Host {
-// 	return pool[0]
-// }
-
-// func testPool() HostPool {
-// 	pool := []*UpstreamHost{
-// 		{
-// 			Name: workableServer.URL, // this should resolve (healthcheck test)
-// 		},
-// 		{
-// 			Name: "http://localhost:99998", // this shouldn't
-// 		},
-// 		{
-// 			Name: "http://C",
-// 		},
-// 	}
-// 	return HostPool(pool)
-// }
-
-// func TestRoundRobinPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	rrPolicy := &RoundRobin{}
-// 	request, _ := http.NewRequest("GET", "/", nil)
-
-// 	h := rrPolicy.Select(pool, request)
-// 	// First selected host is 1, because counter starts at 0
-// 	// and increments before host is selected
-// 	if h != pool[1] {
-// 		t.Error("Expected first round robin host to be second host in the pool.")
-// 	}
-// 	h = rrPolicy.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected second round robin host to be third host in the pool.")
-// 	}
-// 	h = rrPolicy.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected third round robin host to be first host in the pool.")
-// 	}
-// 	// mark host as down
-// 	pool[1].Unhealthy = 1
-// 	h = rrPolicy.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected to skip down host.")
-// 	}
-// 	// mark host as up
-// 	pool[1].Unhealthy = 0
-
-// 	h = rrPolicy.Select(pool, request)
-// 	if h == pool[2] {
-// 		t.Error("Expected to balance evenly among healthy hosts")
-// 	}
-// 	// mark host as full
-// 	pool[1].Conns = 1
-// 	pool[1].MaxConns = 1
-// 	h = rrPolicy.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected to skip full host.")
-// 	}
-// }
-
-// func TestLeastConnPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	lcPolicy := &LeastConn{}
-// 	request, _ := http.NewRequest("GET", "/", nil)
-
-// 	pool[0].Conns = 10
-// 	pool[1].Conns = 10
-// 	h := lcPolicy.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected least connection host to be third host.")
-// 	}
-// 	pool[2].Conns = 100
-// 	h = lcPolicy.Select(pool, request)
-// 	if h != pool[0] && h != pool[1] {
-// 		t.Error("Expected least connection host to be first or second host.")
-// 	}
-// }
-
-// func TestCustomPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	customPolicy := &customPolicy{}
-// 	request, _ := http.NewRequest("GET", "/", nil)
-
-// 	h := customPolicy.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected custom policy host to be the first host.")
-// 	}
-// }
-
-// func TestIPHashPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	ipHash := &IPHash{}
-// 	request, _ := http.NewRequest("GET", "/", nil)
-// 	// We should be able to predict where every request is routed.
-// 	request.RemoteAddr = "172.0.0.1:80"
-// 	h := ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.2:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.3:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected ip hash policy host to be the third host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.4:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-
-// 	// we should get the same results without a port
-// 	request.RemoteAddr = "172.0.0.1"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.2"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.3"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected ip hash policy host to be the third host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.4"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-
-// 	// we should get a healthy host if the original host is unhealthy and a
-// 	// healthy host is available
-// 	request.RemoteAddr = "172.0.0.1"
-// 	pool[1].Unhealthy = 1
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected ip hash policy host to be the third host.")
-// 	}
-
-// 	request.RemoteAddr = "172.0.0.2"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[2] {
-// 		t.Error("Expected ip hash policy host to be the third host.")
-// 	}
-// 	pool[1].Unhealthy = 0
-
-// 	request.RemoteAddr = "172.0.0.3"
-// 	pool[2].Unhealthy = 1
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected ip hash policy host to be the first host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.4"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-
-// 	// We should be able to resize the host pool and still be able to predict
-// 	// where a request will be routed with the same IP's used above
-// 	pool = []*UpstreamHost{
-// 		{
-// 			Name: workableServer.URL, // this should resolve (healthcheck test)
-// 		},
-// 		{
-// 			Name: "http://localhost:99998", // this shouldn't
-// 		},
-// 	}
-// 	pool = HostPool(pool)
-// 	request.RemoteAddr = "172.0.0.1:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected ip hash policy host to be the first host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.2:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.3:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected ip hash policy host to be the first host.")
-// 	}
-// 	request.RemoteAddr = "172.0.0.4:80"
-// 	h = ipHash.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected ip hash policy host to be the second host.")
-// 	}
-
-// 	// We should get nil when there are no healthy hosts
-// 	pool[0].Unhealthy = 1
-// 	pool[1].Unhealthy = 1
-// 	h = ipHash.Select(pool, request)
-// 	if h != nil {
-// 		t.Error("Expected ip hash policy host to be nil.")
-// 	}
-// }
-
-// func TestFirstPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	firstPolicy := &First{}
-// 	req := httptest.NewRequest(http.MethodGet, "/", nil)
-
-// 	h := firstPolicy.Select(pool, req)
-// 	if h != pool[0] {
-// 		t.Error("Expected first policy host to be the first host.")
-// 	}
-
-// 	pool[0].Unhealthy = 1
-// 	h = firstPolicy.Select(pool, req)
-// 	if h != pool[1] {
-// 		t.Error("Expected first policy host to be the second host.")
-// 	}
-// }
-
-// func TestUriPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	uriPolicy := &URIHash{}
-
-// 	request := httptest.NewRequest(http.MethodGet, "/test", nil)
-// 	h := uriPolicy.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected uri policy host to be the first host.")
-// 	}
-
-// 	pool[0].Unhealthy = 1
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected uri policy host to be the first host.")
-// 	}
-
-// 	request = httptest.NewRequest(http.MethodGet, "/test_2", nil)
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected uri policy host to be the second host.")
-// 	}
-
-// 	// We should be able to resize the host pool and still be able to predict
-// 	// where a request will be routed with the same URI's used above
-// 	pool = []*UpstreamHost{
-// 		{
-// 			Name: workableServer.URL, // this should resolve (healthcheck test)
-// 		},
-// 		{
-// 			Name: "http://localhost:99998", // this shouldn't
-// 		},
-// 	}
-
-// 	request = httptest.NewRequest(http.MethodGet, "/test", nil)
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != pool[0] {
-// 		t.Error("Expected uri policy host to be the first host.")
-// 	}
-
-// 	pool[0].Unhealthy = 1
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected uri policy host to be the first host.")
-// 	}
-
-// 	request = httptest.NewRequest(http.MethodGet, "/test_2", nil)
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != pool[1] {
-// 		t.Error("Expected uri policy host to be the second host.")
-// 	}
-
-// 	pool[0].Unhealthy = 1
-// 	pool[1].Unhealthy = 1
-// 	h = uriPolicy.Select(pool, request)
-// 	if h != nil {
-// 		t.Error("Expected uri policy policy host to be nil.")
-// 	}
-// }
-
-// func TestHeaderPolicy(t *testing.T) {
-// 	pool := testPool()
-// 	tests := []struct {
-// 		Name               string
-// 		Policy             *Header
-// 		RequestHeaderName  string
-// 		RequestHeaderValue string
-// 		NilHost            bool
-// 		HostIndex          int
-// 	}{
-// 		{"empty config", &Header{""}, "", "", true, 0},
-// 		{"empty config+header+value", &Header{""}, "Affinity", "somevalue", true, 0},
-// 		{"empty config+header", &Header{""}, "Affinity", "", true, 0},
-
-// 		{"no header(fallback to roundrobin)", &Header{"Affinity"}, "", "", false, 1},
-// 		{"no header(fallback to roundrobin)", &Header{"Affinity"}, "", "", false, 2},
-// 		{"no header(fallback to roundrobin)", &Header{"Affinity"}, "", "", false, 0},
-
-// 		{"hash route to host", &Header{"Affinity"}, "Affinity", "somevalue", false, 1},
-// 		{"hash route to host", &Header{"Affinity"}, "Affinity", "somevalue2", false, 0},
-// 		{"hash route to host", &Header{"Affinity"}, "Affinity", "somevalue3", false, 2},
-// 		{"hash route with empty value", &Header{"Affinity"}, "Affinity", "", false, 1},
-// 	}
-
-// 	for idx, test := range tests {
-// 		request, _ := http.NewRequest("GET", "/", nil)
-// 		if test.RequestHeaderName != "" {
-// 			request.Header.Add(test.RequestHeaderName, test.RequestHeaderValue)
-// 		}
-
-// 		host := test.Policy.Select(pool, request)
-// 		if test.NilHost && host != nil {
-// 			t.Errorf("%d: Expected host to be nil", idx)
-// 		}
-// 		if !test.NilHost && host == nil {
-// 			t.Errorf("%d: Did not expect host to be nil", idx)
-// 		}
-// 		if !test.NilHost && host != pool[test.HostIndex] {
-// 			t.Errorf("%d: Expected Header policy to be host %d", idx, test.HostIndex)
-// 		}
-// 	}
-// }
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func testPool() UpstreamPool {
+	return UpstreamPool{
+		{Host: new(upstreamHost)},
+		{Host: new(upstreamHost)},
+		{Host: new(upstreamHost)},
+	}
+}
+
+func TestRoundRobinPolicy(t *testing.T) {
+	pool := testPool()
+	rrPolicy := new(RoundRobinSelection)
+	req, _ := http.NewRequest("GET", "/", nil)
+
+	h := rrPolicy.Select(pool, req)
+	// First selected host is 1, because counter starts at 0
+	// and increments before host is selected
+	if h != pool[1] {
+		t.Error("Expected first round robin host to be second host in the pool.")
+	}
+	h = rrPolicy.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected second round robin host to be third host in the pool.")
+	}
+	h = rrPolicy.Select(pool, req)
+	if h != pool[0] {
+		t.Error("Expected third round robin host to be first host in the pool.")
+	}
+	// mark host as down
+	pool[1].SetHealthy(false)
+	h = rrPolicy.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected to skip down host.")
+	}
+	// mark host as up
+	pool[1].SetHealthy(true)
+
+	h = rrPolicy.Select(pool, req)
+	if h == pool[2] {
+		t.Error("Expected to balance evenly among healthy hosts")
+	}
+	// mark host as full
+	pool[1].CountRequest(1)
+	pool[1].MaxRequests = 1
+	h = rrPolicy.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected to skip full host.")
+	}
+}
+
+func TestLeastConnPolicy(t *testing.T) {
+	pool := testPool()
+	lcPolicy := new(LeastConnSelection)
+	req, _ := http.NewRequest("GET", "/", nil)
+
+	pool[0].CountRequest(10)
+	pool[1].CountRequest(10)
+	h := lcPolicy.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected least connection host to be third host.")
+	}
+	pool[2].CountRequest(100)
+	h = lcPolicy.Select(pool, req)
+	if h != pool[0] && h != pool[1] {
+		t.Error("Expected least connection host to be first or second host.")
+	}
+}
+
+func TestIPHashPolicy(t *testing.T) {
+	pool := testPool()
+	ipHash := new(IPHashSelection)
+	req, _ := http.NewRequest("GET", "/", nil)
+
+	// We should be able to predict where every request is routed.
+	req.RemoteAddr = "172.0.0.1:80"
+	h := ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+	req.RemoteAddr = "172.0.0.2:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+	req.RemoteAddr = "172.0.0.3:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected ip hash policy host to be the third host.")
+	}
+	req.RemoteAddr = "172.0.0.4:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+
+	// we should get the same results without a port
+	req.RemoteAddr = "172.0.0.1"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+	req.RemoteAddr = "172.0.0.2"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+	req.RemoteAddr = "172.0.0.3"
+	h = ipHash.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected ip hash policy host to be the third host.")
+	}
+	req.RemoteAddr = "172.0.0.4"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+
+	// we should get a healthy host if the original host is unhealthy and a
+	// healthy host is available
+	req.RemoteAddr = "172.0.0.1"
+	pool[1].SetHealthy(false)
+	h = ipHash.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected ip hash policy host to be the third host.")
+	}
+
+	req.RemoteAddr = "172.0.0.2"
+	h = ipHash.Select(pool, req)
+	if h != pool[2] {
+		t.Error("Expected ip hash policy host to be the third host.")
+	}
+	pool[1].SetHealthy(true)
+
+	req.RemoteAddr = "172.0.0.3"
+	pool[2].SetHealthy(false)
+	h = ipHash.Select(pool, req)
+	if h != pool[0] {
+		t.Error("Expected ip hash policy host to be the first host.")
+	}
+	req.RemoteAddr = "172.0.0.4"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+
+	// We should be able to resize the host pool and still be able to predict
+	// where a req will be routed with the same IP's used above
+	pool = UpstreamPool{
+		{Host: new(upstreamHost)},
+		{Host: new(upstreamHost)},
+	}
+	req.RemoteAddr = "172.0.0.1:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[0] {
+		t.Error("Expected ip hash policy host to be the first host.")
+	}
+	req.RemoteAddr = "172.0.0.2:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+	req.RemoteAddr = "172.0.0.3:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[0] {
+		t.Error("Expected ip hash policy host to be the first host.")
+	}
+	req.RemoteAddr = "172.0.0.4:80"
+	h = ipHash.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected ip hash policy host to be the second host.")
+	}
+
+	// We should get nil when there are no healthy hosts
+	pool[0].SetHealthy(false)
+	pool[1].SetHealthy(false)
+	h = ipHash.Select(pool, req)
+	if h != nil {
+		t.Error("Expected ip hash policy host to be nil.")
+	}
+}
+
+func TestFirstPolicy(t *testing.T) {
+	pool := testPool()
+	firstPolicy := new(FirstSelection)
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+
+	h := firstPolicy.Select(pool, req)
+	if h != pool[0] {
+		t.Error("Expected first policy host to be the first host.")
+	}
+
+	pool[0].SetHealthy(false)
+	h = firstPolicy.Select(pool, req)
+	if h != pool[1] {
+		t.Error("Expected first policy host to be the second host.")
+	}
+}
+
+func TestURIHashPolicy(t *testing.T) {
+	pool := testPool()
+	uriPolicy := new(URIHashSelection)
+
+	request := httptest.NewRequest(http.MethodGet, "/test", nil)
+	h := uriPolicy.Select(pool, request)
+	if h != pool[0] {
+		t.Error("Expected uri policy host to be the first host.")
+	}
+
+	pool[0].SetHealthy(false)
+	h = uriPolicy.Select(pool, request)
+	if h != pool[1] {
+		t.Error("Expected uri policy host to be the first host.")
+	}
+
+	request = httptest.NewRequest(http.MethodGet, "/test_2", nil)
+	h = uriPolicy.Select(pool, request)
+	if h != pool[1] {
+		t.Error("Expected uri policy host to be the second host.")
+	}
+
+	// We should be able to resize the host pool and still be able to predict
+	// where a request will be routed with the same URI's used above
+	pool = UpstreamPool{
+		{Host: new(upstreamHost)},
+		{Host: new(upstreamHost)},
+	}
+
+	request = httptest.NewRequest(http.MethodGet, "/test", nil)
+	h = uriPolicy.Select(pool, request)
+	if h != pool[0] {
+		t.Error("Expected uri policy host to be the first host.")
+	}
+
+	pool[0].SetHealthy(false)
+	h = uriPolicy.Select(pool, request)
+	if h != pool[1] {
+		t.Error("Expected uri policy host to be the first host.")
+	}
+
+	request = httptest.NewRequest(http.MethodGet, "/test_2", nil)
+	h = uriPolicy.Select(pool, request)
+	if h != pool[1] {
+		t.Error("Expected uri policy host to be the second host.")
+	}
+
+	pool[0].SetHealthy(false)
+	pool[1].SetHealthy(false)
+	h = uriPolicy.Select(pool, request)
+	if h != nil {
+		t.Error("Expected uri policy policy host to be nil.")
+	}
+}