Support standalone mode for framework functions

kyaml/fn/framework/framework_test.go

@@ -4,6 +4,7 @@
 package framework_test
 
 import (
+	"bytes"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -11,6 +12,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework"
+	"sigs.k8s.io/kustomize/kyaml/testutil"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
 func TestCommand_dockerfile(t *testing.T) {
@@ -50,3 +53,53 @@ CMD ["function"]
 		t.FailNow()
 	}
 }
+
+// TestCommand_standalone tests the framework works in standalone mode
+func TestCommand_standalone(t *testing.T) {
+	// TODO: make this test pass on windows -- currently failure seems spurious
+	testutil.SkipWindows(t)
+
+	type api = struct {
+		A string `json:"a" yaml:"a"`
+	}
+	var config api
+
+	resourceList := &framework.ResourceList{FunctionConfig: &config}
+	cmd := framework.Command(resourceList, func() error {
+		resourceList.Items = append(resourceList.Items, yaml.MustParse(`
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: bar1
+  namespace: default
+  annotations:
+    foo: bar1
+`))
+
+		for i := range resourceList.Items {
+			err := resourceList.Items[i].PipeE(yaml.SetAnnotation("a", config.A))
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+	cmd.SetArgs([]string{
+		filepath.Join("testdata", "command", "config.yaml"),
+		filepath.Join("testdata", "command", "input.yaml"),
+	})
+	var out bytes.Buffer
+	cmd.SetOutput(&out)
+	if !assert.NoError(t, cmd.Execute()) {
+		t.FailNow()
+	}
+
+	expected, err := ioutil.ReadFile(filepath.Join("testdata", "command", "expected.yaml"))
+	if !assert.NoError(t, err) {
+		t.FailNow()
+	}
+	if !assert.Equal(t, string(expected), out.String()) {
+		t.FailNow()
+	}
+}