Move kubeconfig loader utils to cmdutil pkg

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

internal/kubeconfig/helpers_test.go

@@ -1 +0,0 @@
-package kubeconfig

internal/kubeconfig/namespace.go

@@ -0,0 +1,39 @@
+package kubeconfig
+
+import (
+	"github.com/pkg/errors"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	defaultNamespace = "default"
+)
+
+func (k *Kubeconfig) contextNode(name string) (*yaml.Node, error) {
+	contexts := valueOf(k.rootNode, "contexts")
+	if contexts == nil {
+		return nil, errors.New("\"contexts\" entry is nil")
+	} else if contexts.Kind != yaml.SequenceNode {
+		return nil, errors.New("\"contexts\" is not a sequence node")
+	}
+
+	for _, contextNode := range contexts.Content {
+		nameNode := valueOf(contextNode, "name")
+		if nameNode.Kind == yaml.ScalarNode && nameNode.Value == name {
+			return contextNode, nil
+		}
+	}
+	return nil, errors.Errorf("context with name %q not found", name)
+}
+
+func (k *Kubeconfig) NamespaceOfContext(contextName string) (string, error) {
+	ctx, err := k.contextNode(contextName)
+	if err != nil {
+		return "", err
+	}
+	ns := valueOf(ctx, "namespace")
+	if ns == nil || ns.Value == "" {
+		return defaultNamespace, nil
+	}
+	return ns.Value, nil
+}

internal/kubeconfig/namespace_test.go

@@ -0,0 +1,46 @@
+package kubeconfig
+
+import (
+	"testing"
+
+	"github.com/ahmetb/kubectx/internal/testutil"
+)
+
+func TestKubeconfig_NamespaceOfContext_ctxNotFound(t *testing.T) {
+	kc := new(Kubeconfig).WithLoader(WithMockKubeconfigLoader(testutil.KC().
+		WithCtxs(testutil.Ctx("c1")).ToYAML(t)))
+	if err := kc.Parse(); err != nil {
+		t.Fatal(err)
+	}
+
+	_, err := kc.NamespaceOfContext("c2")
+	if err == nil {
+		t.Fatal("expected err")
+	}
+}
+
+func TestKubeconfig_NamespaceOfContext(t *testing.T) {
+	kc := new(Kubeconfig).WithLoader(WithMockKubeconfigLoader(testutil.KC().
+		WithCtxs(
+			testutil.Ctx("c1"),
+			testutil.Ctx("c2").Ns("c2n1")).ToYAML(t)))
+	if err := kc.Parse(); err != nil {
+		t.Fatal(err)
+	}
+
+	v1, err := kc.NamespaceOfContext("c1")
+	if err != nil {
+		t.Fatal("expected err")
+	}
+	if expected := `default`; v1 != expected {
+		t.Fatalf("c1: expected=%q got=%q", expected, v1)
+	}
+
+	v2, err := kc.NamespaceOfContext("c2")
+	if err != nil {
+		t.Fatal("expected err")
+	}
+	if expected := `c2n1`; v2 != expected {
+		t.Fatalf("c2: expected=%q got=%q", expected, v2)
+	}
+}