fix: transpile step (#12)

* fix: transpile step

- remove the unecessary tools.Build step
- add GO111MODULE=off to remove the error related to the absence of
  go.mod
- filter error correctly according to file notification
- see NOTEs for more contextualized infos

* chore: reduce log severity

Author: tbruyelle

internal/lsp/build.go

@@ -20,47 +20,49 @@ type ErrorInfo struct {
 	Tool     string
 }
 
-func (s *server) TranspileAndBuild(file *GnoFile) ([]ErrorInfo, error) {
-	pkgDir := filepath.Dir(file.URI.Filename())
-	pkgName := filepath.Base(pkgDir)
-	tmpDir := filepath.Join(s.env.GNOHOME, "gnopls", "tmp", pkgName)
+func (s *server) Transpile() ([]ErrorInfo, error) {
+	moduleName := filepath.Base(s.workspaceFolder)
+	tmpDir := filepath.Join(s.env.GNOHOME, "gnopls", "tmp", moduleName)
 
-	err := copyDir(pkgDir, tmpDir)
+	err := copyDir(s.workspaceFolder, tmpDir)
 	if err != nil {
 		return nil, err
 	}
 
-	preOut, _ := tools.Transpile(tmpDir)
-	slog.Info(string(preOut))
+	preOut, errTranspile := tools.Transpile(tmpDir)
 	if len(preOut) > 0 {
-		return parseErrors(file, string(preOut), "transpile")
+		// parse errors even if errTranspile!=nil bc that's always the case if
+		// there's errors to parse.
+		slog.Info("transpile error", "out", string(preOut), "err", errTranspile)
+		errors, errParse := s.parseErrors(string(preOut), "transpile")
+		if errParse != nil {
+			return nil, errParse
+		}
+		if len(errors) == 0 && errTranspile != nil {
+			// no parsed errors but errTranspile!=nil, this is an unexpected error.
+			// (for example the gno binary was not found)
+			return nil, errTranspile
+		}
+		return errors, nil
 	}
-
-	buildOut, _ := tools.Build(tmpDir)
-	slog.Info(string(buildOut))
-	return parseErrors(file, string(buildOut), "build")
+	return nil, nil
 }
 
 // This is used to extract information from the `gno build` command
 // (see `parseError` below).
 //
 // TODO: Maybe there's a way to get this in a structured format?
+// -> will be available in go1.24 with `go build -json`
 var errorRe = regexp.MustCompile(`(?m)^([^#]+?):(\d+):(\d+):(.+)$`)
 
-// parseErrors parses the output of the `gno build` command for errors.
-//
-// They look something like this:
+// parseErrors parses the output of the `gno transpile -gobuild` command for
+// errors.
 //
+// The format is:
 // ```
-// command-line-arguments
-// # command-line-arguments
-// <file>:20:9: undefined: strin
-//
-// <pkg_path>: build pkg: std go compiler: exit status 1
-//
-// 1 go build errors
+// <file.gno>:<line>:<col>: <error>
 // ```
-func parseErrors(file *GnoFile, output, cmd string) ([]ErrorInfo, error) {
+func (s *server) parseErrors(output, cmd string) ([]ErrorInfo, error) {
 	errors := []ErrorInfo{}
 
 	matches := errorRe.FindAllStringSubmatch(output, -1)
@@ -69,24 +71,39 @@ func parseErrors(file *GnoFile, output, cmd string) ([]ErrorInfo, error) {
 	}
 
 	for _, match := range matches {
+		path := match[1]
 		line, err := strconv.Atoi(match[2])
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("parseErrors '%s': %w", match, err)
 		}
 
 		column, err := strconv.Atoi(match[3])
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("parseErrors '%s': %w", match, err)
 		}
-		slog.Info("parsing", "line", line, "column", column, "msg", match[4])
-
-		errorInfo := findError(file, match[1], line, column, match[4], cmd)
-		errors = append(errors, errorInfo)
+		msg := strings.TrimSpace(match[4])
+		slog.Debug("parseErrors", "path", path, "line", line, "column", column, "msg", msg)
+		errors = append(errors, ErrorInfo{
+			FileName: filepath.Join(s.workspaceFolder, path),
+			Line:     line,
+			Column:   column,
+			Span:     []int{column, column},
+			Msg:      msg,
+			Tool:     cmd,
+		})
 	}
 
 	return errors, nil
 }
 
+// NOTE(tb): This function tries to guess the column start and end of the
+// error, by splitting the line into tokens (space separated). While this
+// might work most of the time, in some cases it might not, so I think
+// it is preferable not to try to guess and just return:
+// column_start = column_end
+// just like the output of gno transpile which only returns the start of the
+// column. This is why this function is no longer invoked in parseError.
+//
 // findError finds the error in the document, shifting the line and column
 // numbers to account for the header information in the generated Go file.
 func findError(file *GnoFile, fname string, line, col int, msg string, tool string) ErrorInfo {

internal/lsp/diagnostics.go

@@ -2,32 +2,40 @@ package lsp
 
 import (
 	"context"
-	"path/filepath"
-	"strings"
 
 	"go.lsp.dev/jsonrpc2"
 	"go.lsp.dev/protocol"
 )
 
 func (s *server) getTranspileDiagnostics(file *GnoFile) ([]protocol.Diagnostic, error) {
-	errors, err := s.TranspileAndBuild(file)
+	errors, err := s.Transpile()
 	if err != nil {
 		return nil, err
 	}
 
-	if pkg, ok := s.cache.pkgs.Get(filepath.Dir(string(file.URI.Filename()))); ok {
-		filename := filepath.Base(file.URI.Filename())
-		for _, er := range pkg.TypeCheckResult.Errors() {
-			// Skip errors from other files in the same package
-			if !strings.HasSuffix(er.FileName, filename) {
-				continue
+	/*
+		 NOTE(tb): not sure we really need this, bc Transpile already returns
+		 all the errors we need. The ones in the cache are just duplicates or
+		 potentially obsolete.
+
+		if pkg, ok := s.cache.pkgs.Get(filepath.Dir(string(file.URI.Filename()))); ok {
+			filename := filepath.Base(file.URI.Filename())
+			for _, er := range pkg.TypeCheckResult.Errors() {
+				// Skip errors from other files in the same package
+				if !strings.HasSuffix(er.FileName, filename) {
+					continue
+				}
+				errors = append(errors, er)
 			}
-			errors = append(errors, er)
 		}
-	}
+	*/
 
 	diagnostics := make([]protocol.Diagnostic, 0) // Init required for JSONRPC to send an empty array
 	for _, er := range errors {
+		if file.URI.Filename() != er.FileName {
+			// Ignore error thay does not target file
+			continue
+		}
 		diagnostics = append(diagnostics, protocol.Diagnostic{
 			Range:    *posToRange(er.Line, er.Span),
 			Severity: protocol.DiagnosticSeverityError,

internal/lsp/server.go

@@ -23,7 +23,8 @@ type server struct {
 	completionStore *CompletionStore
 	cache           *Cache
 
-	initialized atomic.Bool
+	initialized     atomic.Bool
+	workspaceFolder string
 }
 
 func BuildServerHandler(conn jsonrpc2.Conn, e *env.Env) jsonrpc2.Handler {
@@ -90,6 +91,15 @@ func (s *server) Initialize(ctx context.Context, reply jsonrpc2.Replier, req jso
 	if err := json.Unmarshal(req.Params(), &params); err != nil {
 		return sendParseError(ctx, reply, err)
 	}
+	if len(params.WorkspaceFolders) > 0 {
+		s.workspaceFolder = params.WorkspaceFolders[0].Name
+	}
+	if s.workspaceFolder == "" {
+		// Not all LSP client have migrated to the latest WorkspaceFolders, some
+		// like vim-lsp are still using the deprecated one RootUri.
+		s.workspaceFolder = params.RootURI.Filename() //nolint:staticcheck
+	}
+	slog.Info("Initialize", "params", params, "workspaceFolder", s.workspaceFolder)
 
 	return reply(ctx, protocol.InitializeResult{
 		ServerInfo: &protocol.ServerInfo{

internal/tools/build.go

@@ -1,11 +1,22 @@
 package tools
 
 import (
+	"fmt"
+	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 )
 
 // Transpile a Gno package: gno transpile <dir>.
 func Transpile(rootDir string) ([]byte, error) {
-	return exec.Command("gno", "transpile", "-skip-imports", filepath.Join(rootDir)).CombinedOutput()
+	cmd := exec.Command("gno", "transpile", "-skip-imports", "-gobuild", filepath.Join(rootDir))
+	// FIXME(tb): See https://github.com/gnolang/gno/pull/1695/files#r1697255524
+	const disableGoMod = "GO111MODULE=off"
+	cmd.Env = append(os.Environ(), disableGoMod)
+	bz, err := cmd.CombinedOutput()
+	if err != nil {
+		return bz, fmt.Errorf("running '%s': %w: %s", strings.Join(cmd.Args, " "), err, string(bz))
+	}
+	return bz, nil
 }

internal/tools/transpile.go

@@ -70,11 +70,11 @@ func Bye() {
           },
           "end": {
             "line": 2,
-            "character": 4294967294
+            "character": 6
           }
         },
         "severity": 1,
-        "code": "typecheck",
+        "code": "transpile",
         "source": "gnopls",
         "message": "undefined: X"
       },
@@ -86,11 +86,11 @@ func Bye() {
           },
           "end": {
             "line": 5,
-            "character": 4294967294
+            "character": 1
           }
         },
         "severity": 1,
-        "code": "typecheck",
+        "code": "transpile",
         "source": "gnopls",
         "message": "declared and not used: y"
       }