Add GetOriginalwd method (#224)

helper/runner.go

@@ -44,6 +44,11 @@ type RuleConfig struct {
 
 var _ tflint.Runner = &Runner{}
 
+// GetOriginalwd always returns the current directory
+func (r *Runner) GetOriginalwd() (string, error) {
+	return os.Getwd()
+}
+
 // GetModulePath always returns the root module path address
 func (r *Runner) GetModulePath() (addrs.Module, error) {
 	return []string{}, nil

plugin/host2plugin/host2plugin_test.go

@@ -540,6 +540,10 @@ type mockServerImpl struct {
 	getFile func(string) (*hcl.File, error)
 }
 
+func (s *mockServer) GetOriginalwd() string {
+	return "/work"
+}
+
 func (s *mockServer) GetModulePath() []string {
 	return []string{}
 }

plugin/plugin2host/client.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"strings"
 
 	"github.com/hashicorp/hcl/v2"
@@ -19,6 +20,8 @@ import (
 	"github.com/zclconf/go-cty/cty/gocty"
 	"github.com/zclconf/go-cty/cty/json"
 	"github.com/zclconf/go-cty/cty/msgpack"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 // GRPCClient is a plugin-side implementation. Plugin can send requests through the client to host's gRPC server.
@@ -28,6 +31,20 @@ type GRPCClient struct {
 
 var _ tflint.Runner = &GRPCClient{}
 
+// GetOriginalwd gets the original working directory.
+func (c *GRPCClient) GetOriginalwd() (string, error) {
+	resp, err := c.Client.GetOriginalwd(context.Background(), &proto.GetOriginalwd_Request{})
+	if err != nil {
+		if st, ok := status.FromError(err); ok && st.Code() == codes.Unimplemented {
+			// Originalwd is available in TFLint v0.44+
+			// Fallback to os.Getwd() because it equals the current directory in earlier versions.
+			return os.Getwd()
+		}
+		return "", fromproto.Error(err)
+	}
+	return resp.Path, err
+}
+
 // GetModulePath gets the current module path address.
 func (c *GRPCClient) GetModulePath() (addrs.Module, error) {
 	resp, err := c.Client.GetModulePath(context.Background(), &proto.GetModulePath_Request{})

plugin/plugin2host/plugin2host_test.go

@@ -35,6 +35,7 @@ type mockServer struct {
 }
 
 type mockServerImpl struct {
+	getOriginalwd        func() string
 	getModulePath        func() []string
 	getModuleContent     func(*hclext.BodySchema, tflint.GetModuleContentOption) (*hclext.BodyContent, hcl.Diagnostics)
 	getFile              func(string) (*hcl.File, error)
@@ -48,6 +49,13 @@ func newMockServer(impl mockServerImpl) *mockServer {
 	return &mockServer{impl: impl}
 }
 
+func (s *mockServer) GetOriginalwd() string {
+	if s.impl.getOriginalwd != nil {
+		return s.impl.getOriginalwd()
+	}
+	return ""
+}
+
 func (s *mockServer) GetModulePath() []string {
 	if s.impl.getModulePath != nil {
 		return s.impl.getModulePath()
@@ -100,6 +108,36 @@ func (s *mockServer) EmitIssue(rule tflint.Rule, message string, location hcl.Ra
 // @see https://github.com/google/go-cmp/issues/40
 var allowAllUnexported = cmp.Exporter(func(reflect.Type) bool { return true })
 
+func TestGetOriginalwd(t *testing.T) {
+	tests := []struct {
+		Name       string
+		ServerImpl func() string
+		Want       string
+	}{
+		{
+			Name: "get the original working directory",
+			ServerImpl: func() string {
+				return "/work"
+			},
+			Want: "/work",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			client := startTestGRPCServer(t, newMockServer(mockServerImpl{getOriginalwd: test.ServerImpl}))
+
+			got, err := client.GetOriginalwd()
+			if err != nil {
+				t.Fatalf("failed to call GetOriginalwd: %s", err)
+			}
+			if diff := cmp.Diff(got, test.Want); diff != "" {
+				t.Errorf("diff: %s", diff)
+			}
+		})
+	}
+}
+
 func TestGetModulePath(t *testing.T) {
 	tests := []struct {
 		Name       string

plugin/plugin2host/server.go

@@ -28,6 +28,7 @@ var _ proto.RunnerServer = &GRPCServer{}
 
 // Server is the interface that the host should implement when a plugin communicates with the host.
 type Server interface {
+	GetOriginalwd() string
 	GetModulePath() []string
 	GetModuleContent(*hclext.BodySchema, tflint.GetModuleContentOption) (*hclext.BodyContent, hcl.Diagnostics)
 	GetFile(string) (*hcl.File, error)
@@ -38,6 +39,11 @@ type Server interface {
 	EmitIssue(rule tflint.Rule, message string, location hcl.Range) error
 }
 
+// GetOriginalwd gets the original working directory.
+func (s *GRPCServer) GetOriginalwd(ctx context.Context, req *proto.GetOriginalwd_Request) (*proto.GetOriginalwd_Response, error) {
+	return &proto.GetOriginalwd_Response{Path: s.Impl.GetOriginalwd()}, nil
+}
+
 // GetModulePath gets the current module path address.
 func (s *GRPCServer) GetModulePath(ctx context.Context, req *proto.GetModulePath_Request) (*proto.GetModulePath_Response, error) {
 	return &proto.GetModulePath_Response{Path: s.Impl.GetModulePath()}, nil