tests: add tests for Validate

This also attempts to make the host name regex a bit
more readable.

Author: dmke

plugin.go

@@ -18,7 +18,8 @@ import (
 )
 
 var hostRegex *regexp.Regexp
-var cacheKey string = "hosts"
+
+const cacheKey = "hosts"
 
 func init() {
 	caddy.RegisterModule(MatchRemoteHost{})
@@ -88,7 +89,15 @@ func (m *MatchRemoteHost) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 func (m *MatchRemoteHost) Provision(ctx caddy.Context) (err error) {
 	m.logger = ctx.Logger()
 	m.cache = cache.New(1*time.Minute, 2*time.Minute)
-	hostRegex, err = regexp.Compile(`^((([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9]))$`)
+
+	const (
+		alnum     = "[a-zA-Z0-9]"
+		alnumDash = "[-a-zA-Z0-9]"
+		label     = "(" + alnum + "|" + alnum + alnumDash + "*" + alnum + ")"
+		hostname  = "^(" + label + `\.)*` + label + "$"
+	)
+
+	hostRegex, err = regexp.Compile(hostname)
 	return err
 }
 

plugin_test.go

@@ -4,8 +4,10 @@ package caddy_remote_host_test
 // methods see package caddy_remote_host.
 
 import (
+	"fmt"
 	"testing"
 
+	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
 	plugin "github.com/muety/caddy-remote-host"
 	"github.com/stretchr/testify/assert"
@@ -114,3 +116,51 @@ func TestMatchRemoteHost_UnmarshalCaddyfile_invalid(t *testing.T) {
 		})
 	}
 }
+
+func TestMatchRemoteHost_Validate(t *testing.T) {
+	for name, hosts := range map[string][]string{
+		"single":         {"example"},
+		"simple":         {"example.com"},
+		"multiple":       {"example.com", "example.org"},
+		"subdomain":      {"sub.example.com"},
+		"hyphens":        {"ex-am-ple.com"},
+		"digits":         {"example24.com"},
+		"leading digits": {"42example.org"},
+		"only digits":    {"42.example"},
+	} {
+		hosts := hosts
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			subject := plugin.MatchRemoteHost{Hosts: hosts}
+			require.NoError(t, subject.Provision(caddy.Context{}))
+			assert.NoError(t, subject.Validate())
+		})
+	}
+}
+
+func TestMatchRemoteHost_Validate_invalid(t *testing.T) {
+	require := require.New(t)
+	assert := assert.New(t)
+
+	for name, host := range map[string]string{
+		"dot":           ".",
+		"double dot":    "example..com",
+		"leading dot":   ".example.org",
+		"leading dash":  "-example.org",
+		"trailing dash": "example-.org",
+		"underscore":    "_http.example",
+		"non-acsii":     "ëxample.com",
+		"wildcard":      "*.example.com",
+	} {
+		host := host
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			subject := plugin.MatchRemoteHost{Hosts: []string{host}}
+			require.NoError(subject.Provision(caddy.Context{}))
+			assert.EqualError(subject.Validate(),
+				fmt.Sprintf("'%s' is not a valid host name", host))
+		})
+	}
+}