test(view): improve test coverage (#7543)

Cover edge cases in config parser. Add rudimentary View/Filter
tests. Improves test coverage from 44% to 82%.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

plugin/view/setup_test.go

@@ -1,9 +1,14 @@
 package view
 
 import (
+	"context"
+	"errors"
 	"testing"
 
 	"github.com/coredns/caddy"
+	ptest "github.com/coredns/coredns/plugin/test"
+
+	"github.com/miekg/dns"
 )
 
 func TestSetup(t *testing.T) {
@@ -17,6 +22,8 @@ func TestSetup(t *testing.T) {
 		{"view example {\n expr name() == 'example.com.'\n expr name() == 'example2.com.'\n}", false, 2},
 		{"view", true, 0},
 		{"view example {\n expr invalid expression\n}", true, 0},
+		{"view x {\n foo bar\n}\n", true, 0},
+		{"view a { }\nview b { }\n", true, 0},
 	}
 
 	for i, test := range tests {
@@ -36,3 +43,21 @@ func TestSetup(t *testing.T) {
 		}
 	}
 }
+
+func TestServeDNS_DelegatesToNext(t *testing.T) {
+	v := &View{}
+	wantCode := 123
+	wantErr := errors.New("boom")
+	v.Next = ptest.NextHandler(wantCode, wantErr)
+
+	rr := new(dns.Msg)
+	rr.SetQuestion("example.com.", dns.TypeA)
+	w := &ptest.ResponseWriter{}
+	gotCode, gotErr := v.ServeDNS(context.Background(), w, rr)
+	if gotCode != wantCode {
+		t.Fatalf("rcode: got %d, want %d", gotCode, wantCode)
+	}
+	if gotErr != wantErr {
+		t.Fatalf("error: got %v, want %v", gotErr, wantErr)
+	}
+}