fix(go): fix syntax error in generated source for VisitUndiscriminatedUnion

generators/go/internal/generator/file_writer.go

@@ -186,7 +186,25 @@ func removeUnusedImports(filename string, buf []byte) ([]byte, error) {
 	fset := token.NewFileSet()
 	f, err := parser.ParseFile(fset, filename, buf, parser.ParseComments)
 	if err != nil {
-		return nil, fmt.Errorf("failed to parse Go code: %v", err)
+		badMetadata := strings.Split(err.Error(), ":")
+		badLine, _ := strconv.Atoi(badMetadata[1])
+		badLineCharIdx, _ := strconv.Atoi(badMetadata[2])
+
+		badSrcLines := strings.Split(string(bytes.ToValidUTF8(buf, []byte{'?'})), "\n")
+		badSrc := ""
+		maxLineDigitCount := len(fmt.Sprint(len(badSrcLines)))
+		for i, line := range badSrcLines {
+			if i >= badLine-5 && i <= badLine+3 {
+				if i == badLine-1 {
+					badSrc += "\n"
+				}
+				badSrc += fmt.Sprintf("%"+fmt.Sprint(maxLineDigitCount)+"d: %s\n", i+1, line)
+				if i == badLine-1 {
+					badSrc += strings.Repeat(" ", badLineCharIdx+maxLineDigitCount+1) + "^\n"
+				}
+			}
+		}
+		return nil, fmt.Errorf("failed to parse Go code: %w; source:\n=-=\n%s", err, badSrc)
 	}
 
 	imports := make(map[string]string)

generators/go/internal/generator/generator.go

@@ -126,7 +126,7 @@ func New(config *Config, coordinator *coordinator.Client) (*Generator, error) {
 func (g *Generator) Generate(mode Mode) ([]*File, error) {
 	ir, err := readIR(g.config.IRFilepath)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to read IR: %w", err)
 	}
 	return g.generate(ir, mode)
 }
@@ -202,7 +202,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 				referencedImportPath := fernFilepathToImportPath(g.config.ImportPath, referencedType.FernFilepath)
 				if typeImportPath != referencedImportPath {
 					return nil, fmt.Errorf(
-						"%s referneces %s from another package, but a generator import path was not specified",
+						"%s references %s from another package, but a generator import path was not specified",
 						typeDeclaration.Name.TypeId,
 						referencedType.TypeId,
 					)
@@ -214,7 +214,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 	rootPackageName := getRootPackageName(ir, g.config.PackageName)
 	cycleInfo, err := cycleInfoFromIR(ir, g.config.ImportPath)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to cycle info from IR: %w", err)
 	}
 	if cycleInfo != nil {
 		for _, leafType := range cycleInfo.LeafTypes {
@@ -341,11 +341,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 			g.config.ModuleConfig,
 			g.config.Version,
 		); err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to write request options definition: %w", err)
 		}
 		file, err := writer.File()
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 		}
 		files = append(files, file)
 		if ir.Environments != nil {
@@ -366,11 +366,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 			)
 			generatedEnvironment, err = writer.WriteEnvironments(ir.Environments, useCore)
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to write environments: %w", err)
 			}
 			file, err = writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 		}
@@ -391,11 +391,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 		)
 		generatedAuth, err = writer.WriteRequestOptions(ir.Auth, ir.Headers)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to write request options: %w", err)
 		}
 		file, err = writer.File()
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 		}
 		files = append(files, file)
 		rootClientInstantiation = generatedClientInstantiation(
@@ -420,11 +420,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 				g.coordinator,
 			)
 			if err := writer.WriteIdempotentRequestOptionsDefinition(ir.IdempotencyHeaders); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to write idempotent request options definition: %w", err)
 			}
 			file, err = writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 			fileInfo = fileInfoForIdempotentRequestOptions()
@@ -442,11 +442,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 				g.coordinator,
 			)
 			if err := writer.WriteIdempotentRequestOptions(ir.IdempotencyHeaders); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to write idempotent request options: %w", err)
 			}
 			file, err = writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 		}
@@ -467,11 +467,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 				g.coordinator,
 			)
 			if err = writer.WriteLegacyClientOptions(ir.Auth, ir.Headers, ir.IdempotencyHeaders); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to write legacy client options: %w", err)
 			}
 			file, err = writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 		}
@@ -492,11 +492,11 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 		)
 		if g.config.EnableExplicitNull {
 			if err := writer.WriteOptionalHelpers(useCore); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to write optional helpers: %w", err)
 			}
 			file, err = writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 			files = append(files, newOptionalFile(g.coordinator))
@@ -529,7 +529,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 		}
 		clientTestFile, err := newClientTestFile(g.config.ImportPath, g.coordinator)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to create new client test file: %w", err)
 		}
 		files = append(files, clientTestFile)
 		// Generate the error types, if any.
@@ -549,12 +549,12 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 			)
 			for _, irError := range irErrors {
 				if err := writer.WriteError(irError); err != nil {
-					return nil, err
+					return nil, fmt.Errorf("failed to write error type: %w", err)
 				}
 			}
 			file, err := writer.File()
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to open new writer.File: %w", err)
 			}
 			files = append(files, file)
 		}
@@ -579,7 +579,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 					ir.RootPackage.FernFilepath,
 				)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("failed to generate service: %w", err)
 				}
 				files = append(files, file)
 
@@ -594,7 +594,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 					rootClientInstantiation,
 				)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("failed to generate root service without endpoints: %w", err)
 				}
 				files = append(files, file)
 
@@ -631,7 +631,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 					subpackageToGenerate.OriginalFernFilepath,
 				)
 				if err != nil {
-					return nil, err
+					return nil, fmt.Errorf("failed to generate service without endpoints: %w", err)
 				}
 				files = append(files, file)
 				continue
@@ -645,7 +645,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 				subpackageToGenerate.OriginalFernFilepath,
 			)
 			if err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to generate service: %w", err)
 			}
 			files = append(files, file)
 
@@ -656,7 +656,7 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 	// Write the snippets, if any.
 	if g.config.SnippetFilepath != "" {
 		if err := maybeWriteSnippets(g.coordinator, generatedRootClient, g.config.SnippetFilepath); err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to write snippets: %w", err)
 		}
 	}
 	// Finally, generate the go.mod file, if needed.
@@ -667,13 +667,13 @@ func (g *Generator) generate(ir *fernir.IntermediateRepresentation, mode Mode) (
 		requiresGenerics := g.config.EnableExplicitNull || ir.SdkConfig.HasStreamingEndpoints || generatedPagination
 		file, generatedGoVersion, err := NewModFile(g.coordinator, g.config.ModuleConfig, requiresGenerics)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("failed to create new go.mod file: %w", err)
 		}
 		files = append(files, file)
 
 		if g.config.IncludeReadme && generatedRootClient.Instantiation != nil {
 			if err := g.generateReadme(generatedRootClient, generatedGoVersion); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("failed to generate readme: %w", err)
 			}
 			files = append(files, file)
 		}

generators/go/internal/generator/model.go

@@ -884,9 +884,9 @@ func (t *typeVisitor) VisitUndiscriminatedUnion(union *ir.UndiscriminatedUnionTy
 	for _, member := range members {
 		field := fmt.Sprintf("%s.%s", receiver, member.field)
 		if member.date != nil && !member.isOptional {
-			t.writer.P(fmt.Sprintf("if %s.typ == %q || !%s.IsZero() {", receiver, member.field, field))
+			t.writer.P(fmt.Sprintf("if (%s.typ == %q || !%s.IsZero()) {", receiver, member.field, field))
 		} else {
-			t.writer.P(fmt.Sprintf("if %s.typ == %q || %s != %s {", receiver, member.field, field, member.zeroValue))
+			t.writer.P(fmt.Sprintf("if (%s.typ == %q || %s != %s) {", receiver, member.field, field, member.zeroValue))
 		}
 		if member.isLiteral {
 			// If we have a literal, we need to marshal it directly.
@@ -918,9 +918,9 @@ func (t *typeVisitor) VisitUndiscriminatedUnion(union *ir.UndiscriminatedUnionTy
 	for _, member := range members {
 		field := fmt.Sprintf("%s.%s", receiver, member.field)
 		if member.date != nil && !member.isOptional {
-			t.writer.P(fmt.Sprintf("if %s.typ == %q || !%s.IsZero() {", receiver, member.field, field))
+			t.writer.P(fmt.Sprintf("if (%s.typ == %q || !%s.IsZero()) {", receiver, member.field, field))
 		} else {
-			t.writer.P(fmt.Sprintf("if %s.typ == %q || %s != %s {", receiver, member.field, field, member.zeroValue))
+			t.writer.P(fmt.Sprintf("if (%s.typ == %q || %s != %s) {", receiver, member.field, field, member.zeroValue))
 		}
 		t.writer.P("return visitor.Visit", strings.Title(member.field), "(", receiver, ".", member.field, ")")
 		t.writer.P("}")