rego+bundle: Fix issues underlying #3209 (#3444)

* bundle: cleanup path before setting it as baseDir

GetBundleDirectoryLoader will do it again, but we need the cleaned-up
`path` to avoid "file:/" parts erroneously making it into the bundle's
ModuleFile structs. GetBundleDirectoryLoader is shared with the server,
so we'll keep that as-is.

* rego: avoid (*Bundle).ParsedModules(..)

Using this will prefix a path that is already complete. Using ModuleFile's
Path instead, we get the already-resolved path.

Signed-off-by: Stephan Renatus <stephan.renatus@gmail.com>

loader/loader.go

@@ -178,6 +178,10 @@ func (fl fileLoader) Filtered(paths []string, filter Filter) (*Result, error) {
 // it will be treated as a normal tarball bundle. If a directory
 // is supplied it will be loaded as an unzipped bundle tree.
 func (fl fileLoader) AsBundle(path string) (*bundle.Bundle, error) {
+	path, err := fileurl.Clean(path)
+	if err != nil {
+		return nil, err
+	}
 	bundleLoader, isDir, err := GetBundleDirectoryLoader(path)
 	if err != nil {
 		return nil, err

loader/loader_test.go

@@ -411,8 +411,9 @@ func TestAsBundleWithDir(t *testing.T) {
 
 func TestAsBundleWithFileURLDir(t *testing.T) {
 	files := map[string]string{
-		"/foo/data.json": "[1,2,3]",
-		"/.manifest":     `{"roots": ["foo"]}`,
+		"/foo/data.json":   "[1,2,3]",
+		"/foo/policy.rego": "package foo.bar\np = 1",
+		"/.manifest":       `{"roots": ["foo"]}`,
 	}
 
 	test.WithTempFS(files, func(rootDir string) {
@@ -425,6 +426,18 @@ func TestAsBundleWithFileURLDir(t *testing.T) {
 			t.Fatalf("Expected bundle to be non-nil")
 		}
 
+		if len(b.Modules) != 1 {
+			t.Fatalf("expected 1 modules, got %d", len(b.Modules))
+		}
+		expectedModulePaths := map[string]struct{}{
+			filepath.Join(rootDir, "/foo/policy.rego"): {},
+		}
+		for _, mf := range b.Modules {
+			if _, found := expectedModulePaths[mf.Path]; !found {
+				t.Errorf("Unexpected module file with path %s in bundle modules", mf.Path)
+			}
+		}
+
 		expectedData := util.MustUnmarshalJSON([]byte(`{"foo": [1,2,3]}`))
 		if !reflect.DeepEqual(b.Data, expectedData) {
 			t.Fatalf("expected data %+v, got %+v", expectedData, b.Data)