Pull request: all: imp some tests

Merge in DNS/adguard-home from imp-tests to master

Squashed commit of the following:

commit 6171420068d66808f069f280a81e0c60e61e5ce3
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Mar 25 17:43:36 2021 +0300

    aghnet: imp test msgs

commit ed2880ff03ab0e41a77f07aad2caf13bf5f4bd9f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Mar 25 17:39:44 2021 +0300

    all: imp some tests

internal/aghnet/ipdetector_test.go

@@ -13,7 +13,7 @@ func TestIPDetector_detectSpecialNetwork(t *testing.T) {
 	var err error
 
 	ipd, err = NewIPDetector()
-	require.Nil(t, err)
+	require.NoError(t, err)
 
 	testCases := []struct {
 		name string

internal/aghnet/net_linux_test.go

@@ -49,7 +49,8 @@ func TestDHCPCDStaticConfig(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			r := bytes.NewReader(tc.data)
 			has, err := dhcpcdStaticConfig(r, "wlan0")
-			require.Nil(t, err)
+			require.NoError(t, err)
+
 			assert.Equal(t, tc.want, has)
 		})
 	}
@@ -86,7 +87,8 @@ func TestIfacesStaticConfig(t *testing.T) {
 		t.Run(tc.name, func(t *testing.T) {
 			r := bytes.NewReader(tc.data)
 			has, err := ifacesStaticConfig(r, "enp0s3")
-			require.Nil(t, err)
+			require.NoError(t, err)
+
 			assert.Equal(t, tc.want, has)
 		})
 	}

internal/aghnet/net_test.go

@@ -8,9 +8,9 @@ import (
 
 func TestGetValidNetInterfacesForWeb(t *testing.T) {
 	ifaces, err := GetValidNetInterfacesForWeb()
-	require.Nilf(t, err, "Cannot get net interfaces: %s", err)
-	require.NotEmpty(t, ifaces, "No net interfaces found")
+	require.NoErrorf(t, err, "cannot get net interfaces: %s", err)
+	require.NotEmpty(t, ifaces, "no net interfaces found")
 	for _, iface := range ifaces {
-		require.NotEmptyf(t, iface.Addresses, "No addresses found for %s", iface.Name)
+		require.NotEmptyf(t, iface.Addresses, "no addresses found for %s", iface.Name)
 	}
 }