Expose two Read methods in gktest (#1651)

I have an opportunity to re-use code made written in gktest, as long as
the necessary functions are public.  This PR makes the following two
functions in the gktest package public.  They are (with their newly
capitalized names):

- ReadTemplate()
- ReadObject()

Signed-off-by: juliankatz <[email protected]>

pkg/gktest/read_constraints.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io/fs"
 	"strings"
-	"sync"
 
 	templatesv1 "github.com/open-policy-agent/frameworks/constraint/pkg/apis/templates/v1"
 	"github.com/open-policy-agent/frameworks/constraint/pkg/core/templates"
@@ -72,13 +71,10 @@ func readUnstructured(bytes []byte) (*unstructured.Unstructured, error) {
 	return u, nil
 }
 
-// TODO(willbeason): Remove once ToVersionless() is threadsafe.
-var versionlessMtx sync.Mutex
-
-// readTemplate reads the contents of the path and returns the
+// ReadTemplate reads the contents of the path and returns the
 // ConstraintTemplate it defines. Returns an error if the file does not define
 // a ConstraintTemplate.
-func readTemplate(scheme *runtime.Scheme, f fs.FS, path string) (*templates.ConstraintTemplate, error) {
+func ReadTemplate(scheme *runtime.Scheme, f fs.FS, path string) (*templates.ConstraintTemplate, error) {
 	bytes, err := fs.ReadFile(f, path)
 	if err != nil {
 		return nil, fmt.Errorf("reading ConstraintTemplate from %q: %w", path, err)
@@ -118,9 +114,7 @@ func readTemplate(scheme *runtime.Scheme, f fs.FS, path string) (*templates.Cons
 		return nil, fmt.Errorf("%w: %T", ErrConvertingTemplate, t)
 	}
 
-	versionlessMtx.Lock()
 	template, err := v.ToVersionless()
-	versionlessMtx.Unlock()
 	if err != nil {
 		// This shouldn't happen unless there's a bug in the conversion functions.
 		// Most likely it means the conversion functions weren't generated.
@@ -130,7 +124,10 @@ func readTemplate(scheme *runtime.Scheme, f fs.FS, path string) (*templates.Cons
 	return template, nil
 }
 
-func readObject(f fs.FS, path string) (*unstructured.Unstructured, error) {
+// ReadObject reads a file from the filesystem abstraction at the specified
+// path, and returns an unstructured.Unstructured object if the file can be
+// successfully unmarshalled.
+func ReadObject(f fs.FS, path string) (*unstructured.Unstructured, error) {
 	bytes, err := fs.ReadFile(f, path)
 	if err != nil {
 		return nil, fmt.Errorf("reading Constraint from %q: %w", path, err)
@@ -145,7 +142,7 @@ func readObject(f fs.FS, path string) (*unstructured.Unstructured, error) {
 }
 
 func readConstraint(f fs.FS, path string) (*unstructured.Unstructured, error) {
-	u, err := readObject(f, path)
+	u, err := ReadObject(f, path)
 	if err != nil {
 		return nil, err
 	}

pkg/gktest/runner.go

@@ -165,7 +165,7 @@ func (r *Runner) addTemplate(ctx context.Context, suiteDir, templatePath string,
 		return fmt.Errorf("%w: missing template", ErrInvalidSuite)
 	}
 
-	template, err := readTemplate(r.scheme, r.filesystem, path.Join(suiteDir, templatePath))
+	template, err := ReadTemplate(r.scheme, r.filesystem, path.Join(suiteDir, templatePath))
 	if err != nil {
 		return err
 	}