Soong variables reader

Test: go test soong_variables_test.go
Bug: 182395579
Change-Id: I54af165455a7c3de826bf34db6ab88a05e15ca21

mk2rbc/soong_variables_test.go

@@ -0,0 +1,51 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mk2rbc
+
+import (
+	"fmt"
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+type dirResolverForTest struct {
+	ScopeBase
+}
+
+func (t dirResolverForTest) Get(name string) string {
+	if name != "BUILD_SYSTEM" {
+		return fmt.Sprintf("$(%s)", name)
+	}
+	return getTestDirectory()
+}
+
+func TestSoongVariables(t *testing.T) {
+	testFile := filepath.Join(getTestDirectory(), "soong_variables.mk.test")
+	var actual testVariables
+	if err := FindSoongVariables(testFile, dirResolverForTest{}, &actual); err != nil {
+		t.Fatal(err)
+	}
+	expected := testVariables{[]testVar{
+		{"BUILD_ID", VarClassSoong, starlarkTypeString},
+		{"PLATFORM_SDK_VERSION", VarClassSoong, starlarkTypeInt},
+		{"DEVICE_PACKAGE_OVERLAYS", VarClassSoong, starlarkTypeList},
+		{"ENABLE_CFI", VarClassSoong, starlarkTypeBool},
+		{"ENABLE_PREOPT", VarClassSoong, starlarkTypeBool},
+	}}
+	if !reflect.DeepEqual(expected, actual) {
+		t.Errorf("\nExpected: %v\n  Actual: %v", expected, actual)
+	}
+}