Update directory loading convention

Previously, the loader would use directory names as top-level keys when
paths referred to directories. This meant that identical queries against
policies/data in differently named directories would return different
answers.

Now, the loader ignores the first directory name when recursing on
paths. Unfortunately this is not backwards compatible. Scripts and
workflows can be adapted as follows:

Before: opa test *
After:  opa test .

Before: opa test /some/path/to/dir/*
After:  opa test /some/path/to/dir

The same goes for opa run.

loader/loader.go

@@ -152,7 +152,7 @@ func all(paths []string, f func(*Result, string) error) (*Result, error) {
 		}
 
 		if info.IsDir() {
-			loadDirRecursive(&errors, path, loaded.withParent(info.Name()))
+			loadDirRecursive(&errors, path, loaded)
 		} else {
 			err := f(loaded, path)
 			if err != nil {

loader/loader_test.go

@@ -108,7 +108,7 @@ func TestLoadGuessYAML(t *testing.T) {
 
 func TestLoadDirRecursive(t *testing.T) {
 	files := map[string]string{
-		"/a/data1.json": `[1,2,3]`,
+		"/a/data1.json": `{"a": [1,2,3]}`,
 		"/a/e.rego":     `package q`,
 		"/b/data2.yaml": `{"aaa": {"bbb": 1}}`,
 		"/b/data3.yaml": `{"aaa": {"ccc": 2}}`,
@@ -127,13 +127,11 @@ func TestLoadDirRecursive(t *testing.T) {
 		{
 			"zzz": "b",
 			"a": [1,2,3],
-			"b": {
-				"aaa": {
-					"bbb": 1,
-					"ccc": 2
-				},
-				"d": null
-			}
+			"aaa": {
+				"bbb": 1,
+				"ccc": 2
+			},
+			"d": null
 		}
 		`)
 		if !reflect.DeepEqual(loaded.Documents, expectedDocuments) {
@@ -154,9 +152,9 @@ func TestLoadDirRecursive(t *testing.T) {
 
 func TestLoadRooted(t *testing.T) {
 	files := map[string]string{
-		"/foo.json":     "[1,2,3]",
-		"/bar.yaml":     "abc",
-		"/baz/qux.json": "null",
+		"/foo.json":         "[1,2,3]",
+		"/bar/bar.yaml":     "abc",
+		"/baz/qux/qux.json": "null",
 	}
 
 	test.WithTempFS(files, func(rootDir string) {
@@ -170,7 +168,7 @@ func TestLoadRooted(t *testing.T) {
 			t.Fatalf("Unexpected error: %v", err)
 		}
 		expected := parseJSON(`
-		{"four": [1,2,3], "one": {"two": "abc"}, "three": {"baz": null}}
+		{"four": [1,2,3], "one": {"two": "abc"}, "three": {"qux": null}}
 		`)
 		if !reflect.DeepEqual(loaded.Documents, expected) {
 			t.Fatalf("Expected %v but got: %v", expected, loaded.Documents)

runtime/runtime_test.go

@@ -159,7 +159,7 @@ func TestRuntimeProcessWatchEvents(t *testing.T) {
 		}
 
 		t0 := time.Now()
-		path := storage.MustParsePath("/" + path.Base(rootDir) + "/some")
+		path := storage.MustParsePath("/some")
 
 		// In practice, reload takes ~100us on development machine.
 		maxWaitTime := time.Second * 1