diff --git a/util/testutil/testing.go b/util/testutil/testing.go
new file mode 100644
index 0000000000..270ad6c42c
--- /dev/null
+++ b/util/testutil/testing.go
@@ -0,0 +1,58 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2014 Ben Johnson
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package testutil
+
+import (
+	"fmt"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+// Assert fails the test if the condition is false.
+func Assert(tb testing.TB, condition bool, msg string, v ...interface{}) {
+	if !condition {
+		_, file, line, _ := runtime.Caller(1)
+		fmt.Printf("\033[31m%s:%d: "+msg+"\033[39m\n\n", append([]interface{}{filepath.Base(file), line}, v...)...)
+		tb.FailNow()
+	}
+}
+
+// Ok fails the test if an err is not nil.
+func Ok(tb testing.TB, err error) {
+	if err != nil {
+		_, file, line, _ := runtime.Caller(1)
+		fmt.Printf("\033[31m%s:%d: unexpected error: %s\033[39m\n\n", filepath.Base(file), line, err.Error())
+		tb.FailNow()
+	}
+}
+
+// Equals fails the test if exp is not equal to act.
+func Equals(tb testing.TB, exp, act interface{}) {
+	if !reflect.DeepEqual(exp, act) {
+		_, file, line, _ := runtime.Caller(1)
+		fmt.Printf("\033[31m%s:%d:\n\n\texp: %#v\n\n\tgot: %#v\033[39m\n\n", filepath.Base(file), line, exp, act)
+		tb.FailNow()
+	}
+}
diff --git a/web/web_test.go b/web/web_test.go
index ffe8ce2257..b17a0b1c20 100644
--- a/web/web_test.go
+++ b/web/web_test.go
@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/prometheus/prometheus/storage/tsdb"
+	"github.com/prometheus/prometheus/util/testutil"
 	libtsdb "github.com/prometheus/tsdb"
 )
 
@@ -65,31 +66,28 @@ func TestGlobalURL(t *testing.T) {
 		},
 	}
 
-	for i, test := range tests {
+	for _, test := range tests {
 		inURL, err := url.Parse(test.inURL)
-		if err != nil {
-			t.Fatalf("%d. Error parsing input URL: %s", i, err)
-		}
+
+		testutil.Ok(t, err)
+
 		globalURL := tmplFuncs("", opts)["globalURL"].(func(u *url.URL) *url.URL)
 		outURL := globalURL(inURL)
 
-		if outURL.String() != test.outURL {
-			t.Fatalf("%d. got %s, want %s", i, outURL.String(), test.outURL)
-		}
+		testutil.Equals(t, test.outURL, outURL.String())
 	}
 }
 
 func TestReadyAndHealthy(t *testing.T) {
 	t.Parallel()
 	dbDir, err := ioutil.TempDir("", "tsdb-ready")
-	if err != nil {
-		t.Fatalf("Unexpected error creating a tmpDir: %s", err)
-	}
+
+	testutil.Ok(t, err)
+
 	defer os.RemoveAll(dbDir)
 	db, err := libtsdb.Open(dbDir, nil, nil, nil)
-	if err != nil {
-		t.Fatalf("Unexpected error opening empty dir: %s", err)
-	}
+
+	testutil.Ok(t, err)
 
 	opts := &Options{
 		ListenAddress:  ":9090",
@@ -117,100 +115,70 @@ func TestReadyAndHealthy(t *testing.T) {
 	time.Sleep(5 * time.Second)
 
 	resp, err := http.Get("http://localhost:9090/-/healthy")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /-/healthy with server unready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9090/-/ready")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path /-/ready with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9090/version")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path /version with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9090/api/v2/admin/tsdb/snapshot", "", strings.NewReader(""))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path /api/v2/admin/tsdb/snapshot with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9090/api/v2/admin/tsdb/delete_series", "", strings.NewReader("{}"))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path /api/v2/admin/tsdb/delete_series with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	// Set to ready.
 	webHandler.Ready()
 
 	resp, err = http.Get("http://localhost:9090/-/healthy")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /-/healthy with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9090/-/ready")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /-/ready with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9090/version")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /version with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9090/api/v2/admin/tsdb/snapshot", "", strings.NewReader(""))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /api/v2/admin/tsdb/snapshot with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9090/api/v2/admin/tsdb/delete_series", "", strings.NewReader("{}"))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path /api/v2/admin/tsdb/delete_series with server unready test, Expected status 503 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 }
 
 func TestRoutePrefix(t *testing.T) {
 	t.Parallel()
 	dbDir, err := ioutil.TempDir("", "tsdb-ready")
-	if err != nil {
-		t.Fatalf("Unexpected error creating a tmpDir: %s", err)
-	}
+
+	testutil.Ok(t, err)
+
 	defer os.RemoveAll(dbDir)
+
 	db, err := libtsdb.Open(dbDir, nil, nil, nil)
-	if err != nil {
-		t.Fatalf("Unexpected error opening empty dir: %s", err)
-	}
+
+	testutil.Ok(t, err)
 
 	opts := &Options{
 		ListenAddress:  ":9091",
@@ -243,87 +211,57 @@ func TestRoutePrefix(t *testing.T) {
 	time.Sleep(5 * time.Second)
 
 	resp, err := http.Get("http://localhost:9091" + opts.RoutePrefix + "/-/healthy")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path %s/-/healthy with server unready test, Expected status 200 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9091" + opts.RoutePrefix + "/-/ready")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path %s/-/ready with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9091" + opts.RoutePrefix + "/version")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path %s/version with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9091"+opts.RoutePrefix+"/api/v2/admin/tsdb/snapshot", "", strings.NewReader(""))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path %s/api/v2/admin/tsdb/snapshot with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9091"+opts.RoutePrefix+"/api/v2/admin/tsdb/delete_series", "", strings.NewReader("{}"))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusServiceUnavailable {
-		t.Fatalf("Path %s/api/v2/admin/tsdb/delete_series with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusServiceUnavailable, resp.StatusCode)
 
 	// Set to ready.
 	webHandler.Ready()
 
 	resp, err = http.Get("http://localhost:9091" + opts.RoutePrefix + "/-/healthy")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path "+opts.RoutePrefix+"/-/healthy with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9091" + opts.RoutePrefix + "/-/ready")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path "+opts.RoutePrefix+"/-/ready with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Get("http://localhost:9091" + opts.RoutePrefix + "/version")
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path "+opts.RoutePrefix+"/version with server ready test, Expected status 200 got: %s", resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9091"+opts.RoutePrefix+"/api/v2/admin/tsdb/snapshot", "", strings.NewReader(""))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path %s/api/v2/admin/tsdb/snapshot with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 
 	resp, err = http.Post("http://localhost:9091"+opts.RoutePrefix+"/api/v2/admin/tsdb/delete_series", "", strings.NewReader("{}"))
-	if err != nil {
-		t.Fatalf("Unexpected HTTP error %s", err)
-	}
-	if resp.StatusCode != http.StatusOK {
-		t.Fatalf("Path %s/api/v2/admin/tsdb/delete_series with server unready test, Expected status 503 got: %s", opts.RoutePrefix, resp.Status)
-	}
+
+	testutil.Ok(t, err)
+	testutil.Equals(t, http.StatusOK, resp.StatusCode)
 }
 
 func TestDebugHandler(t *testing.T) {
@@ -348,14 +286,13 @@ func TestDebugHandler(t *testing.T) {
 		handler.Ready()
 
 		w := httptest.NewRecorder()
+
 		req, err := http.NewRequest("GET", tc.url, nil)
-		if err != nil {
-			t.Fatalf("Unexpected error %s", err)
-		}
+
+		testutil.Ok(t, err)
 
 		handler.router.ServeHTTP(w, req)
-		if w.Code != tc.code {
-			t.Fatalf("Unexpected status code %d: %s", w.Code, w.Body.String())
-		}
+
+		testutil.Equals(t, tc.code, w.Code)
 	}
 }