Merge pull request #8 from sttts/sttts-is-valid

Add Name.IsValid

Author: stevekuznetsov

name.go

@@ -19,6 +19,7 @@ package logicalcluster
 import (
 	"encoding/json"
 	"path"
+	"regexp"
 	"strings"
 )
 
@@ -47,6 +48,13 @@ func New(value string) Name {
 	return Name{value}
 }
 
+// NewValidated returns a Name from a string and whether it is a valid logical cluster.
+// A valid logical cluster returns true on IsValid().
+func NewValidated(value string) (Name, bool) {
+	n := Name{value}
+	return n, n.IsValid()
+}
+
 // Empty returns true if the logical cluster value is unset.
 func (n Name) Empty() bool {
 	return n.value == ""
@@ -121,3 +129,11 @@ func (n *Name) UnmarshalJSON(data []byte) error {
 func (n Name) HasPrefix(other Name) bool {
 	return strings.HasPrefix(n.value, other.value)
 }
+
+var lclusterRegExp = regexp.MustCompile(`^[a-z][a-z0-9-]*[a-z0-9](:[a-z][a-z0-9-]*[a-z0-9])*$`)
+
+// IsValid returns true if the name is a Wildcard or a colon separated list of words where each word
+// starts with a lower-case letter and contains only lower-case letters, digits and hyphens.
+func (n Name) IsValid() bool {
+	return n == Wildcard || lclusterRegExp.MatchString(n.value)
+}

name_test.go

@@ -68,3 +68,45 @@ func TestJSON(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, jwt, jwt2)
 }
+
+func TestIsValidCluster(t *testing.T) {
+	tests := []struct {
+		name  string
+		valid bool
+	}{
+		{"", false},
+		{"*", true},
+
+		{"elephant", true},
+		{"elephant:foo", true},
+		{"elephant:foo:bar", true},
+
+		{"system", true},
+		{"system:foo", true},
+		{"system:foo:bar", true},
+
+		// the plugin does not decide about segment length, the server does
+		{"elephant:b1234567890123456789012345678912", true},
+		{"elephant:test-8827a131-f796-4473-8904-a0fa527696eb:b1234567890123456789012345678912", true},
+		{"elephant:test-too-long-org-0020-4473-0030-a0fa-0040-5276-0050-sdg2-0060:b1234567890123456789012345678912", true},
+
+		{"elephant:", false},
+		{":elephant", false},
+		{"elephant::foo", false},
+		{"elephant:föö:bär", false},
+		{"elephant:bar_bar", false},
+		{"elephant:a", false},
+		{"elephant:0a", false},
+		{"elephant:0bar", false},
+		{"elephant/bar", false},
+		{"elephant:bar-", false},
+		{"elephant:-bar", false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := New(tt.name).IsValid(); got != tt.valid {
+				t.Errorf("isValid(%q) = %v, want %v", tt.name, got, tt.valid)
+			}
+		})
+	}
+}