linter fixes open-telemetry#4

instrgen/driver/instrgen_test.go

@@ -54,7 +54,6 @@ func TestInstrumentation(t *testing.T) {
 		rewriter := rewriters.BasicRewriter{
 			FilePattern: k, Replace: "yes", Pkg: "main", Fun: "main"}
 		analyzePackage(rewriter, "main", filePaths, nil, "", args)
-
 	}
 	fmt.Println(cwd)
 
@@ -86,5 +85,4 @@ func TestInstrumentation(t *testing.T) {
 			panic("not all files were compared")
 		}
 	}
-
 }

instrgen/driver/main.go

@@ -21,7 +21,6 @@ import (
 	"go/parser"
 	"go/printer"
 	"go/token"
-	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -31,19 +30,20 @@ import (
 	"go.opentelemetry.io/contrib/instrgen/rewriters"
 )
 
-func usage() error {
+func usage() {
 	fmt.Println("\nusage driver --command [file pattern] replace entrypoint")
 	fmt.Println("\tcommand:")
 	fmt.Println("\t\tinject                                 (injects open telemetry calls into project code)")
 	fmt.Println("\t\tprune                                  (prune open telemetry calls")
-	return nil
 }
 
+// Entry point function.
 type EntryPoint struct {
 	Pkg     string
 	FunName string
 }
 
+// Command passed to the compiler toolchain.
 type InstrgenCmd struct {
 	ProjectPath string
 	FilePattern string
@@ -64,7 +64,6 @@ func isDirectory(path string) (bool, error) {
 func executeCommand(command string, projectPath string, packagePattern string, replaceSource string, entryPoint string) error {
 	isDir, err := isDirectory(projectPath)
 	if !isDir {
-		_ = usage()
 		return errors.New("[path to go project] argument must be directory")
 	}
 	if err != nil {
@@ -79,13 +78,13 @@ func executeCommand(command string, projectPath string, packagePattern string, r
 		file, _ := json.MarshalIndent(data, "", " ")
 		err = os.WriteFile("instrgen_cmd.json", file, 0644)
 		if err != nil {
-			log.Fatal(err)
+			fmt.Println(err)
 			return nil
 		}
 		cmd := exec.Command("go", "build", "-work", "-a", "-toolexec", "driver")
 		fmt.Println("invoke : " + cmd.String())
 		if err := cmd.Run(); err != nil {
-			log.Fatal(err)
+			fmt.Println(err)
 		}
 		return nil
 	case "--prune":
@@ -97,7 +96,7 @@ func executeCommand(command string, projectPath string, packagePattern string, r
 		cmd := exec.Command("go", "build", "-work", "-a", "-toolexec", "driver")
 		fmt.Println("invoke : " + cmd.String())
 		if err := cmd.Run(); err != nil {
-			log.Fatal(err)
+			fmt.Println(err)
 		}
 		return nil
 	default:
@@ -107,7 +106,6 @@ func executeCommand(command string, projectPath string, packagePattern string, r
 
 func checkArgs(args []string) error {
 	if len(args) < 4 {
-		_ = usage()
 		return errors.New("wrong arguments")
 	}
 	return nil
@@ -149,15 +147,15 @@ func createFile(name string) (*os.File, error) {
 
 func analyzePackage(rewriter alib.PackageRewriter, pkg string, filePaths map[string]int, trace *os.File, destPath string, args []string) []string {
 	fset := token.NewFileSet()
-	trace.WriteString(rewriter.Id() + " pkg:" + pkg + ":" + destPath)
-	trace.WriteString("\n")
+	_, err := trace.WriteString(rewriter.Id() + " pkg:" + pkg + ":" + destPath + "\n")
+	if err != nil {
+		return nil
+	}
 	extraFilesWritten := false
 	for filePath, index := range filePaths {
 		file, err := parser.ParseFile(fset, filePath, nil, parser.ParseComments)
-
 		if err != nil {
-			trace.WriteString(err.Error())
-			trace.WriteString("\n")
+			// TODO handle that
 			continue
 		}
 		if rewriter.Inject(pkg, filePath) {
@@ -167,50 +165,39 @@ func analyzePackage(rewriter alib.PackageRewriter, pkg string, filePaths map[str
 				var out *os.File
 				out, err = createFile(fset.File(file.Pos()).Name() + "tmp")
 				if err != nil {
-					trace.WriteString(err.Error())
-					trace.WriteString("\n")
 					continue
 				}
 				err = printer.Fprint(out, fset, file)
 				if err != nil {
-					trace.WriteString(err.Error())
-					trace.WriteString("\n")
 					continue
 				}
 				oldFileName := fset.File(file.Pos()).Name() + "tmp"
 				newFileName := fset.File(file.Pos()).Name()
 				err = os.Rename(oldFileName, newFileName)
 				if err != nil {
-					trace.WriteString(err.Error())
-					trace.WriteString("\n")
 					continue
 				}
 			} else {
 				filename := filepath.Base(filePath)
 				out, err := createFile(destPath + "/" + filename)
 				if err != nil {
-					trace.WriteString(err.Error())
-					trace.WriteString("\n")
 					continue
 				}
 				err = printer.Fprint(out, fset, file)
 				if err != nil {
-					trace.WriteString(err.Error())
-					trace.WriteString("\n")
 					continue
 				}
 				args[index] = destPath + "/" + filename
 			}
 			if !extraFilesWritten {
 				files := rewriter.WriteExtraFiles(pkg, destPath)
-				if files != nil && len(files) > 0 {
+				if len(files) > 0 {
 					args = append(args, files...)
 				}
 				extraFilesWritten = true
 			}
 		}
 	}
-
 	return args
 }
 
@@ -268,7 +255,8 @@ func executeCommandProxy(cmdName string) {
 	}
 	err = executeCommand(os.Args[1], ".", os.Args[2], replace, os.Args[4])
 	if err != nil {
-		log.Fatal(err)
+		fmt.Println(err)
+		return
 	}
 }
 
@@ -289,7 +277,6 @@ func main() {
 		case "--rootfunctions":
 			executeCommandProxy(cmdName)
 			return
-
 		}
 		if len(args) > 0 {
 			executePass(args[0:])
@@ -300,13 +287,15 @@ func main() {
 	}
 	content, err := os.ReadFile("./instrgen_cmd.json")
 	if err != nil {
-		log.Fatal("Error when opening file: ", err)
+		fmt.Println("Error when opening file: ", err)
+		return
 	}
 
 	var instrgenCfg InstrgenCmd
 	err = json.Unmarshal(content, &instrgenCfg)
 	if err != nil {
-		log.Fatal("Error during Unmarshal(): ", err)
+		fmt.Println("Error during Unmarshal(): ", err)
+		return
 	}
 
 	var rewriterS []alib.PackageRewriter