Pull request: use testutil

Squashed commit of the following:

commit 5345a14b3565f358c56a37500cafb35b7e397951
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Oct 21 21:13:06 2021 +0300

    all: fix windows tests

commit 8b9cdbe3e78f43339d21277f04e686bb154f6968
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Oct 21 20:23:55 2021 +0300

    all: imp code

commit 271fdbe74c29d8ea4b53d7f56d2a36612dfed7b3
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Oct 21 19:43:32 2021 +0300

    all: imp testing

commit e340f9d48679c57fc8eb579b8b78d4957be111c4
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Oct 21 18:53:51 2021 +0300

    all: use testutil

internal/dhcpd/conn_unix_test.go

@@ -5,9 +5,9 @@ package dhcpd
 
 import (
 	"net"
-	"strings"
 	"testing"
 
+	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
 	"github.com/insomniacslk/dhcp/dhcpv4"
@@ -45,7 +45,7 @@ func TestDHCPConn_WriteTo_common(t *testing.T) {
 		n, err := conn.WriteTo(nil, &unexpectedAddrType{})
 		require.Error(t, err)
 
-		assert.True(t, strings.Contains(err.Error(), "peer is of unexpected type"))
+		testutil.AssertErrorMsg(t, "peer is of unexpected type *dhcpd.unexpectedAddrType", err)
 		assert.Zero(t, n)
 	})
 }

internal/dhcpd/dhcpd_test.go

@@ -68,9 +68,7 @@ func TestDB(t *testing.T) {
 	err = s.dbStore()
 	require.NoError(t, err)
 
-	t.Cleanup(func() {
-		assert.NoError(t, os.Remove(dbFilename))
-	})
+	testutil.CleanupAndRequireSuccess(t, func() (err error) { return os.Remove(dbFilename) })
 
 	err = s.srv4.ResetLeases(nil)
 	require.NoError(t, err)

internal/dhcpd/http_test.go

@@ -15,7 +15,7 @@ func TestServer_notImplemented(t *testing.T) {
 
 	w := httptest.NewRecorder()
 	r, err := http.NewRequest(http.MethodGet, "/unsupported", nil)
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	h(w, r)
 	assert.Equal(t, http.StatusNotImplemented, w.Code)

internal/dhcpd/iprange_test.go

@@ -4,6 +4,7 @@ import (
 	"net"
 	"testing"
 
+	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -64,14 +65,8 @@ func TestNewIPRange(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			r, err := newIPRange(tc.start, tc.end)
-			if tc.wantErrMsg == "" {
-				assert.NoError(t, err)
-				assert.NotNil(t, r)
-			} else {
-				require.Error(t, err)
-				assert.Equal(t, tc.wantErrMsg, err.Error())
-			}
+			_, err := newIPRange(tc.start, tc.end)
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
 		})
 	}
 }

internal/dhcpd/nullbool_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"testing"
 
+	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -45,13 +46,7 @@ func TestNullBool_UnmarshalJSON(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			var got nullBool
 			err := got.UnmarshalJSON(tc.data)
-			if tc.wantErrMsg == "" {
-				assert.NoError(t, err)
-			} else {
-				require.Error(t, err)
-
-				assert.Equal(t, tc.wantErrMsg, err.Error())
-			}
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
 
 			assert.Equal(t, tc.want, got)
 		})

internal/dhcpd/options_unix_test.go

@@ -95,6 +95,7 @@ func TestParseOpt(t *testing.T) {
 			opt, err := parseDHCPOption(tc.in)
 			if tc.wantErrMsg != "" {
 				require.Error(t, err)
+
 				assert.Equal(t, tc.wantErrMsg, err.Error())
 
 				return

internal/dhcpd/v4_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/AdguardTeam/golibs/stringutil"
+	"github.com/AdguardTeam/golibs/testutil"
 	"github.com/insomniacslk/dhcp/dhcpv4"
 	"github.com/mdlayher/raw"
 	"github.com/stretchr/testify/assert"
@@ -430,14 +431,7 @@ func TestNormalizeHostname(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			got, err := normalizeHostname(tc.hostname)
-			if tc.wantErrMsg == "" {
-				assert.NoError(t, err)
-			} else {
-				require.Error(t, err)
-
-				assert.Equal(t, tc.wantErrMsg, err.Error())
-			}
-
+			testutil.AssertErrorMsg(t, tc.wantErrMsg, err)
 			assert.Equal(t, tc.want, got)
 		})
 	}