feat: aggregate go build errors for LSP

fixes #1233
fixes #1237

backend/schema/errors.go

@@ -3,6 +3,7 @@ package schema
 import (
 	"errors"
 	"fmt"
+	"sort"
 
 	schemapb "github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/schema"
 )
@@ -66,11 +67,12 @@ func ErrorListFromProto(e *schemapb.ErrorList) *ErrorList {
 	}
 }
 
-func Errorf(pos Position, endColumn int, format string, args ...any) Error {
-	return Error{Msg: fmt.Sprintf(format, args...), Pos: pos, EndColumn: endColumn}
+func Errorf(pos Position, endColumn int, format string, args ...any) *Error {
+	err := Error{Msg: fmt.Sprintf(format, args...), Pos: pos, EndColumn: endColumn}
+	return &err
 }
 
-func Wrapf(pos Position, endColumn int, err error, format string, args ...any) Error {
+func Wrapf(pos Position, endColumn int, err error, format string, args ...any) *Error {
 	if format == "" {
 		format = "%s"
 	} else {
@@ -88,5 +90,18 @@ func Wrapf(pos Position, endColumn int, err error, format string, args ...any) E
 		newEndColumn = endColumn
 		args = append(args, err)
 	}
-	return Error{Msg: fmt.Sprintf(format, args...), Pos: newPos, EndColumn: newEndColumn}
+	e := Error{Msg: fmt.Sprintf(format, args...), Pos: newPos, EndColumn: newEndColumn}
+	return &e
+}
+
+func SortErrorsByPosition(merr []error) {
+	sort.Slice(merr, func(i, j int) bool {
+		var ipe, jpe Error
+		if errors.As(merr[i], &ipe) && errors.As(merr[j], &jpe) {
+			ipp := ipe.Pos
+			jpp := jpe.Pos
+			return ipp.Line < jpp.Line || (ipp.Line == jpp.Line && ipp.Column < jpp.Column)
+		}
+		return merr[i].Error() < merr[j].Error()
+	})
 }

buildengine/build.go

@@ -54,6 +54,7 @@ func buildModule(ctx context.Context, sch *schema.Schema, module Module) error {
 		for _, e := range errorList.Errors {
 			errs = append(errs, *e)
 		}
+		schema.SortErrorsByPosition(errs)
 		return errors.Join(errs...)
 	}
 

buildengine/build_go.go

@@ -3,7 +3,6 @@ package buildengine
 import (
 	"context"
 	"fmt"
-
 	"github.com/TBD54566975/ftl/backend/schema"
 	"github.com/TBD54566975/ftl/go-runtime/compile"
 )

examples/go/echo/echo.go

@@ -14,18 +14,21 @@ var defaultName = ftl.Config[string]("default")
 
 // An echo request.
 type EchoRequest struct {
-	Name ftl.Option[string] `json:"name"`
+	Name  ftl.Option[string] `json:"name"`
+	Again error
 }
 
+//ftl:export
 type EchoResponse struct {
 	Message string `json:"message"`
+	Error   error
 }
 
 // Echo returns a greeting with the current time.
 //
 //ftl:export
 func Echo(ctx context.Context, req EchoRequest) (EchoResponse, error) {
-	tresp, err := ftl.Call(ctx, time.Time, time.TimeRequest{})
+	tresp, err := ftl.Call(ctx, "", time.TimeRequest{}, "another")
 	if err != nil {
 		return EchoResponse{}, err
 	}

examples/go/time/time.go

@@ -5,7 +5,8 @@ import (
 	"time"
 )
 
-type TimeRequest struct{}
+type TimeRequest struct {
+}
 type TimeResponse struct {
 	Time time.Time
 }

go-runtime/compile/build.go

@@ -105,9 +105,9 @@ func Build(ctx context.Context, moduleDir string, sch *schema.Schema) error {
 	if originalErr := err; err != nil {
 		var schemaErrs []*schema.Error
 		for _, e := range errors.DeduplicateErrors(errors.UnwrapAll(err)) {
-			var ce schema.Error
+			var ce *schema.Error
 			if errors.As(e, &ce) {
-				schemaErrs = append(schemaErrs, &ce)
+				schemaErrs = append(schemaErrs, ce)
 			}
 		}
 		el := schema.ErrorList{

go-runtime/compile/parser.go

@@ -72,7 +72,7 @@ var directiveParser = participle.MustBuild[directiveWrapper](
 	participle.Union[schema.IngressPathComponent](&schema.IngressPathLiteral{}, &schema.IngressPathParameter{}),
 )
 
-func parseDirectives(fset *token.FileSet, docs *ast.CommentGroup) ([]directive, error) {
+func parseDirectives(node ast.Node, fset *token.FileSet, docs *ast.CommentGroup) ([]directive, *schema.Error) {
 	if docs == nil {
 		return nil, nil
 	}
@@ -86,17 +86,18 @@ func parseDirectives(fset *token.FileSet, docs *ast.CommentGroup) ([]directive,
 		directive, err := directiveParser.ParseString(pos.Filename, line.Text[2:])
 		if err != nil {
 			// Adjust the Participle-reported position relative to the AST node.
+			var scerr *schema.Error
 			var perr participle.Error
 			if errors.As(err, &perr) {
 				ppos := schema.Position{}
 				ppos.Filename = pos.Filename
 				ppos.Column += pos.Column + 2
 				ppos.Line = pos.Line
-				err = schema.Errorf(ppos, ppos.Column, "%s", perr.Message())
+				scerr = schema.Errorf(ppos, ppos.Column, "%s", perr.Message())
 			} else {
-				err = fmt.Errorf("%s: %w", pos, err)
+				scerr = wrapf(node, err, "")
 			}
-			return nil, fmt.Errorf("%s: %w", "invalid directive", err)
+			return nil, scerr
 		}
 		directives = append(directives, directive.Directive)
 	}