Move ctx-related YAML parse methods to pkg

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

cmd/kubectx/current.go

@@ -15,12 +15,12 @@ type CurrentOp struct{}
 func (_op CurrentOp) Run(stdout, _ io.Writer) error {
 	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
 	defer kc.Close()
-	rootNode, err := kc.ParseRaw()
+	_, err := kc.ParseRaw()
 	if err != nil {
 		return err
 	}
 
-	v := kubeconfig.GetCurrentContext(rootNode)
+	v := kc.GetCurrentContext()
 	if v == "" {
 		return errors.New("current-context is not set")
 	}

cmd/kubectx/delete.go

@@ -42,7 +42,7 @@ func deleteContext(name string) (deleteName string, wasActiveContext bool, err e
 		return "", false, err
 	}
 
-	cur := kubeconfig.GetCurrentContext(rootNode)
+	cur := kc.GetCurrentContext()
 
 	// resolve "." to a real name
 	if name == "." {
@@ -50,7 +50,7 @@ func deleteContext(name string) (deleteName string, wasActiveContext bool, err e
 		name = cur
 	}
 
-	if !checkContextExists(rootNode, name) {
+	if !kc.ContextExists(name) {
 		return "", false, errors.New("context does not exist")
 	}
 

cmd/kubectx/kubeconfig/contexts.go

@@ -1,9 +1,11 @@
 package kubeconfig
 
-import "gopkg.in/yaml.v3"
+import (
+	"gopkg.in/yaml.v3"
+)
 
-func ContextNames(rootNode *yaml.Node) []string {
-	contexts := valueOf(rootNode, "contexts")
+func (k *Kubeconfig) ContextNames() []string {
+	contexts := valueOf(k.rootNode, "contexts")
 	if contexts == nil {
 		return nil
 	}
@@ -21,17 +23,14 @@ func ContextNames(rootNode *yaml.Node) []string {
 	return ctxNames
 }
 
-// GetCurrentContext returns "current-context" value in given
-// kubeconfig object Node, or returns "" if not found.
-func GetCurrentContext(rootNode *yaml.Node) string {
-	if rootNode.Kind != yaml.MappingNode {
-		return ""
+func (k *Kubeconfig) ContextExists(name string) bool {
+	ctxNames := k.ContextNames()
+	for _, v := range ctxNames {
+		if v == name {
+			return true
+		}
 	}
-	v := valueOf(rootNode, "current-context")
-	if v == nil {
-		return ""
-	}
-	return v.Value
+	return false
 }
 
 func valueOf(mapNode *yaml.Node, key string) *yaml.Node {

cmd/kubectx/kubeconfig/contexts_test.go

@@ -0,0 +1,52 @@
+package kubeconfig
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestKubeconfig_ContextNames(t *testing.T) {
+	tl := &testLoader{in: strings.NewReader(`
+contexts:
+- name: abc
+- name: def
+  field1: value1
+- name: ghi
+  foo:
+    bar: zoo`)}
+
+	kc := new(Kubeconfig).WithLoader(tl)
+	_, err := kc.ParseRaw()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx := kc.ContextNames()
+	expected := []string{"abc", "def", "ghi"}
+	if diff := cmp.Diff(expected, ctx); diff != "" {
+		t.Fatalf("%s", diff)
+	}
+}
+
+func TestKubeconfig_CheckContextExists(t *testing.T) {
+	tl := &testLoader{in: strings.NewReader(`contexts:
+- name: c1
+- name: c2`)}
+
+	kc := new(Kubeconfig).WithLoader(tl)
+	_, err := kc.ParseRaw()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !kc.ContextExists("c1") {
+		t.Fatal("c1 actually exists; reported false")
+	}
+	if !kc.ContextExists("c2") {
+		t.Fatal("c2 actually exists; reported false")
+	}
+	if kc.ContextExists("c3") {
+		t.Fatal("c3 does not exist; but reported true")
+	}
+}

cmd/kubectx/kubeconfig/currentcontext.go

@@ -0,0 +1,28 @@
+package kubeconfig
+
+import (
+	"github.com/pkg/errors"
+	"gopkg.in/yaml.v3"
+)
+
+// GetCurrentContext returns "current-context" value in given
+// kubeconfig object Node, or returns "" if not found.
+func  (k *Kubeconfig) GetCurrentContext() string {
+	if k.rootNode.Kind != yaml.MappingNode {
+		return ""
+	}
+	v := valueOf(k.rootNode, "current-context")
+	if v == nil {
+		return ""
+	}
+	return v.Value
+}
+
+func (k *Kubeconfig) UnsetCurrentContext() error {
+	if k.rootNode.Kind != yaml.MappingNode {
+		return errors.New("kubeconfig file is not a map document")
+	}
+	curCtxValNode := valueOf(k.rootNode, "current-context")
+	curCtxValNode.Value = ""
+	return nil
+}

cmd/kubectx/kubeconfig/currentcontext_test.go

@@ -0,0 +1,58 @@
+package kubeconfig
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestKubeconfig_GetCurrentContext(t *testing.T) {
+	tl := &testLoader{in: strings.NewReader(`current-context: foo`)}
+	kc := new(Kubeconfig).WithLoader(tl)
+	_, err := kc.ParseRaw()
+	if err != nil {
+		t.Fatal(err)
+	}
+	v := kc.GetCurrentContext()
+
+	expected := "foo"
+	if v != expected {
+		t.Fatalf("expected=%q; got=%q", expected, v)
+	}
+}
+
+func TestKubeconfig_GetCurrentContext_missingField(t *testing.T) {
+	tl := &testLoader{in: strings.NewReader(`abc: def`)}
+	kc := new(Kubeconfig).WithLoader(tl)
+	_, err := kc.ParseRaw()
+	if err != nil {
+		t.Fatal(err)
+	}
+	v := kc.GetCurrentContext()
+
+	expected := ""
+	if v != expected {
+		t.Fatalf("expected=%q; got=%q", expected, v)
+	}
+}
+
+func TestKubeconfig_UnsetCurrentContext(t *testing.T) {
+	tl := &testLoader{in: strings.NewReader(`current-context: foo`)}
+	kc := new(Kubeconfig).WithLoader(tl)
+	_, err := kc.ParseRaw()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := kc.UnsetCurrentContext(); err != nil {
+		t.Fatal(err)
+	}
+	if err := kc.Save(); err != nil {
+		t.Fatal(err)
+	}
+
+	out := tl.out.String()
+	expected := `current-context: ""
+`
+	if out != expected {
+		t.Fatalf("expected=%q; got=%q", expected, out)
+	}
+}

cmd/kubectx/kubeconfig/helpers_test.go

@@ -0,0 +1,17 @@
+package kubeconfig
+
+import (
+	"bytes"
+	"strings"
+)
+
+type testLoader struct {
+	in  *strings.Reader
+	out bytes.Buffer
+}
+
+func (t *testLoader) Read(p []byte) (n int, err error)    { return t.in.Read(p) }
+func (t *testLoader) Write(p []byte) (n int, err error)   { return t.out.Write(p) }
+func (t *testLoader) Close() error                        { return nil }
+func (t *testLoader) Reset() error                        { return nil }
+func (t *testLoader) Load() (ReadWriteResetCloser, error) { return t, nil }

cmd/kubectx/list.go

@@ -26,17 +26,17 @@ type ListOp struct{}
 func (_ ListOp) Run(stdout, _ io.Writer) error {
 	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
 	defer kc.Close()
-	rootNode, err := kc.ParseRaw()
+	_, err := kc.ParseRaw()
 	if err != nil {
 		return err
 	}
 
-	ctxs := kubeconfig.ContextNames(rootNode)
+	ctxs := kc.ContextNames()
 	natsort.Sort(ctxs)
 
 	// TODO support KUBECTX_CURRENT_FGCOLOR
 	// TODO support KUBECTX_CURRENT_BGCOLOR
-	cur :=  kubeconfig.GetCurrentContext(rootNode)
+	cur :=  kc.GetCurrentContext()
 	for _, c := range ctxs {
 		s := c
 		if c == cur {

cmd/kubectx/rename.go

@@ -42,16 +42,16 @@ func (op RenameOp) Run(_, stderr io.Writer) error {
 		return err
 	}
 
-	cur := kubeconfig.GetCurrentContext(rootNode)
+	cur := kc.GetCurrentContext()
 	if op.Old == "." {
 		op.Old = cur
 	}
 
-	if !checkContextExists(rootNode, op.Old) {
+	if !kc.ContextExists(op.Old) {
 		return errors.Errorf("context %q not found, can't rename it", op.Old)
 	}
 
-	if checkContextExists(rootNode, op.New) {
+	if kc.ContextExists( op.New) {
 		printWarning(stderr, "context %q exists, overwriting it.", op.New)
 		if err := modifyDocToDeleteContext(rootNode, op.New); err != nil {
 			return errors.Wrap(err, "failed to delete new context to overwrite it")

cmd/kubectx/switch.go

@@ -44,8 +44,8 @@ func switchContext(name string) (string, error) {
 		return "", err
 	}
 
-	prev := kubeconfig.GetCurrentContext(rootNode)
-	if !checkContextExists(rootNode, name) {
+	prev := kc.GetCurrentContext()
+	if !kc.ContextExists(name) {
 		return "", errors.Errorf("no context exists with the name: %q", name)
 	}
 	if err := modifyCurrentContext(rootNode, name); err != nil {
@@ -81,16 +81,6 @@ func swapContext() (string, error) {
 }
 
 
-func checkContextExists(rootNode *yaml.Node, name string) bool {
-	ctxNames := kubeconfig.ContextNames(rootNode)
-	for _, v := range ctxNames {
-		if v == name {
-			return true
-		}
-	}
-	return false
-}
-
 // TODO delete
 func valueOf(mapNode *yaml.Node, key string) *yaml.Node {
 	if mapNode.Kind != yaml.MappingNode {

cmd/kubectx/unset.go

@@ -5,7 +5,6 @@ import (
 	"io"
 
 	"github.com/pkg/errors"
-	"gopkg.in/yaml.v3"
 
 	"github.com/ahmetb/kubectx/cmd/kubectx/kubeconfig"
 )
@@ -17,12 +16,12 @@ func (_ UnsetOp) Run(_, stderr io.Writer) error {
 	kc := new(kubeconfig.Kubeconfig).WithLoader(defaultLoader)
 	defer kc.Close()
 
-	rootNode, err := kc.ParseRaw()
+	_, err := kc.ParseRaw()
 	if err != nil {
 		return err
 	}
 
-	if err := modifyDocToUnsetContext(rootNode); err != nil {
+	if err := kc.UnsetCurrentContext(); err != nil {
 		return errors.Wrap(err, "error while modifying current-context")
 	}
 	if err := kc.Save(); err != nil {
@@ -33,11 +32,3 @@ func (_ UnsetOp) Run(_, stderr io.Writer) error {
 	return err
 }
 
-func modifyDocToUnsetContext(rootNode *yaml.Node) error {
-	if rootNode.Kind != yaml.MappingNode {
-		return errors.New("kubeconfig file is not a map document")
-	}
-	curCtxValNode := valueOf(rootNode, "current-context")
-	curCtxValNode.Value = ""
-	return nil
-}