pkg/probe/http: don't compare error strings in tests

TestHTTPProbeChecker fails on the Go1.7 release candidates. The
package's history show that this was the case for Go1.5 and Go1.6
as well.

The test depend on errors holding specific string values, behavior
not guarenteed in the standard library API, and causing new test
failures every minor Go release. Just look for an error rather than
trying to inspect it using string comparison. If we feel this
impacts coverage we can add more test cases.

pkg/probe/http/http_test.go

@@ -32,15 +32,6 @@ import (
 
 const FailureCode int = -1
 
-func containsAny(s string, substrs []string) bool {
-	for _, substr := range substrs {
-		if strings.Contains(s, substr) {
-			return true
-		}
-	}
-	return false
-}
-
 func TestHTTPProbeChecker(t *testing.T) {
 	handleReq := func(s int, body string) func(w http.ResponseWriter, r *http.Request) {
 		return func(w http.ResponseWriter, r *http.Request) {
@@ -54,20 +45,17 @@ func TestHTTPProbeChecker(t *testing.T) {
 		handler    func(w http.ResponseWriter, r *http.Request)
 		reqHeaders http.Header
 		health     probe.Result
-		// go1.5: error message changed for timeout, need to support
-		// both old and new
-		accBodies []string
+		accBody    string
 	}{
 		// The probe will be filled in below.  This is primarily testing that an HTTP GET happens.
 		{
-			handleReq(http.StatusOK, "ok body"),
-			nil,
-			probe.Success,
-			[]string{"ok body"},
+			handler: handleReq(http.StatusOK, "ok body"),
+			health:  probe.Success,
+			accBody: "ok body",
 		},
 		{
 			// Echo handler that returns the contents of request headers in the body
-			func(w http.ResponseWriter, r *http.Request) {
+			handler: func(w http.ResponseWriter, r *http.Request) {
 				w.WriteHeader(200)
 				output := ""
 				for k, arr := range r.Header {
@@ -77,50 +65,40 @@ func TestHTTPProbeChecker(t *testing.T) {
 				}
 				w.Write([]byte(output))
 			},
-			http.Header{
+			reqHeaders: http.Header{
 				"X-Muffins-Or-Cupcakes": {"muffins"},
 			},
-			probe.Success,
-			[]string{
-				"X-Muffins-Or-Cupcakes: muffins",
-			},
+			health:  probe.Success,
+			accBody: "X-Muffins-Or-Cupcakes: muffins",
 		},
 		{
 			// Echo handler that returns the contents of Host in the body
-			func(w http.ResponseWriter, r *http.Request) {
+			handler: func(w http.ResponseWriter, r *http.Request) {
 				w.WriteHeader(200)
 				w.Write([]byte(r.Host))
 			},
-			http.Header{
+			reqHeaders: http.Header{
 				"Host": {"muffins.cupcakes.org"},
 			},
-			probe.Success,
-			[]string{
-				"muffins.cupcakes.org",
-			},
+			health:  probe.Success,
+			accBody: "muffins.cupcakes.org",
 		},
 		{
-			handleReq(FailureCode, "fail body"),
-			nil,
-			probe.Failure,
-			[]string{
-				fmt.Sprintf("HTTP probe failed with statuscode: %d", FailureCode),
-				fmt.Sprintf("malformed HTTP status code \"%d\"", FailureCode),
-			},
+			handler: handleReq(FailureCode, "fail body"),
+			health:  probe.Failure,
 		},
 		{
-			func(w http.ResponseWriter, r *http.Request) {
+			handler: handleReq(http.StatusInternalServerError, "fail body"),
+			health:  probe.Failure,
+		},
+		{
+			handler: func(w http.ResponseWriter, r *http.Request) {
 				time.Sleep(3 * time.Second)
 			},
-			nil,
-			probe.Failure,
-			[]string{
-				"use of closed network connection",
-				"request canceled (Client.Timeout exceeded while awaiting headers)",
-			},
+			health: probe.Failure,
 		},
 	}
-	for _, test := range testCases {
+	for i, test := range testCases {
 		func() {
 			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				test.handler(w, r)
@@ -128,28 +106,30 @@ func TestHTTPProbeChecker(t *testing.T) {
 			defer server.Close()
 			u, err := url.Parse(server.URL)
 			if err != nil {
-				t.Errorf("Unexpected error: %v", err)
+				t.Errorf("case %d: unexpected error: %v", i, err)
 			}
 			_, port, err := net.SplitHostPort(u.Host)
 			if err != nil {
-				t.Errorf("Unexpected error: %v", err)
+				t.Errorf("case %d: unexpected error: %v", i, err)
 			}
 			_, err = strconv.Atoi(port)
 			if err != nil {
-				t.Errorf("Unexpected error: %v", err)
+				t.Errorf("case %d: unexpected error: %v", i, err)
 			}
 			health, output, err := prober.Probe(u, test.reqHeaders, 1*time.Second)
 			if test.health == probe.Unknown && err == nil {
-				t.Errorf("Expected error")
+				t.Errorf("case %d: expected error", i)
 			}
 			if test.health != probe.Unknown && err != nil {
-				t.Errorf("Unexpected error: %v", err)
+				t.Errorf("case %d: unexpected error: %v", i, err)
 			}
 			if health != test.health {
-				t.Errorf("Expected %v, got %v", test.health, health)
+				t.Errorf("case %d: expected %v, got %v", i, test.health, health)
+			}
+			if health != probe.Failure && test.health != probe.Failure {
+				if !strings.Contains(output, test.accBody) {
+					t.Errorf("Expected response body to contain %v, got %v", test.accBody, output)
 				}
-			if !containsAny(output, test.accBodies) {
-				t.Errorf("Expected one of %#v, got %v", test.accBodies, output)
 			}
 		}()
 	}