initial commit

Author: jackHedaya

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+.vscode

_testproj/go.mod

@@ -0,0 +1,7 @@
+module testproj
+
+go 1.22.2
+
+require grr v0.0.0
+
+replace grr => ../

_testproj/main.go

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+package main
+
+import (
+	"fmt"
+	"grr/grr"
+	"os"
+)
+
+func main() {
+	num, err := ReturnSomethingOrError()
+
+	if err != nil {
+		grr.Errorf("MyError: this is your number: %v", num).
+			AddError(err)
+	}
+
+	fmt.Println("Number: ")
+
+}
+
+func ReturnSomethingOrError() (int, error) {
+	file, err := os.Open("filename")
+
+	if err != nil {
+		return 0, err
+	}
+
+	defer file.Close()
+
+	return 1, nil
+}

cmd/main.go

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+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/whiskaway/grr/gen"
+)
+
+func main() {
+	// Read the filename from command line arguments
+	if !isProperLength(os.Args) {
+		println("Usage: go run main.go <folder.go>")
+		os.Exit(1)
+	}
+	filename := getFilename(os.Args)
+
+	fmt.Printf("Finding and replacing grr.Errorf calls in %s/...\n", filename)
+
+	// Find and replace grr.Errorf calls in the file
+	gen.FindAndReplaceErrorsInDir(filename)
+}
+
+func isProperLength(args []string) bool {
+	// check if either file is passed like ./grr <file> or ./grr -- <file>
+
+	if args[1] == "--" && len(args) == 3 {
+		return true
+	}
+
+	if len(os.Args) == 2 {
+		return true
+	}
+
+	return false
+}
+
+func getFilename(args []string) string {
+	if args[1] == "--" {
+		return args[2]
+	}
+	return args[1]
+}

gen/errorFunc.tmpl

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+{{$varlen := len .Vars}}
+
+type {{ .ErrName }} struct {
+  err error
+  op string
+  traits map[grr.Trait]string
+
+  {{- range .Vars }}
+  {{ .Literal }} {{ .Type }}
+  {{- end }}
+}
+
+var _ grr.Error = &{{ .ErrName }}{}
+
+func (e *{{ .ErrName }}) Error() string {
+  return fmt.Sprintf("{{ .Message }}", {{ range $i, $pair := .Vars }}e.{{ $pair.Literal }}{{ if notlast $i $varlen}}, {{ end }}{{ end }})
+}
+
+func (e *{{ .ErrName }}) Unwrap() error {
+  return e.err
+}
+
+func (e *{{ .ErrName }}) AsGrr(err grr.Error) (Error, bool) {
+	E := reflect.TypeOf(err)
+
+	var last error = e.err
+
+	for {
+		if last == nil {
+			return nil, false
+		}
+
+		if _, ok := last.(Error); !ok {
+			return nil, false
+		}
+
+		if reflect.TypeOf(last).ConvertibleTo(E) {
+			return reflect.ValueOf(last).Convert(E).Interface().(Error), true
+		}
+
+		last = last.(Error).Unwrap()
+	}
+}
+
+
+func (e *{{ .ErrName }}) IsGrr(err grr.Error) bool {
+  _, ok := e.AsGrr(err)
+  return ok
+}
+
+func (e *{{ .ErrName }}) AddTrait(trait string, value string) grr.Error {
+  e.traits[trait] = value
+  return e
+}
+
+func (e *{{ .ErrName }}) GetTrait(key grr.Trait) (string, bool) {
+	trait, ok := e.traits[key]
+	return trait, ok
+}
+
+func (e *{{ .ErrName }}) GetTraits() map[grr.Trait]string {
+	traits := make(map[grr.Trait]string)
+	for k, v := range e.traits {
+		traits[k] = v
+	}
+	return traits
+}
+
+
+func (e *{{ .ErrName }}) AddOp(op string) grr.Error {
+  e.op = op
+  return e
+}
+
+func (e *{{ .ErrName }}) GetOp() (string, bool) {
+  return e.op, e.op != ""
+}
+
+func (e *{{ .ErrName }}) AddError(err error) grr.Error {
+  e.err = err
+  return e
+}
+
+func New{{ .ErrName }}({{ range $i, $pair := .Vars }}{{ $pair.Literal }} {{ $pair.Type }}{{ if notlast $i $varlen}}, {{ end }}{{ end }}) grr.Error {
+  return &{{ .ErrName }}{
+    {{- range .Vars }}
+    {{ .Literal }}: {{ .Literal }},
+    {{- end }}
+  }
+}

gen/gen.go

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+package gen
+
+import (
+	_ "embed"
+	"strings"
+
+	"text/template"
+
+	"github.com/whiskaway/grr/grr"
+)
+
+//go:embed errorFunc.tmpl
+var tmpl string
+
+var fns = template.FuncMap{
+	"notlast": func(index int, len int) bool {
+		return index+1 != len
+	},
+}
+
+var tmplGet = template.Must(template.New("").Funcs(fns).Parse(tmpl))
+
+type FnArg struct {
+	Literal string
+	Type    string
+}
+
+type TemplateData struct {
+	ErrName string
+	Vars    []FnArg
+	Message string
+}
+
+var TrIsInternal = grr.NewTrait("IsInternal")
+
+func GenerateErrorFunction(errMsg string, args ...FnArg) (string, error) {
+	op := "Generate"
+
+	if len(errMsg) == 0 || errMsg == "\"\"" {
+		return "", grr.Errorf("NoErrorMessage: error message not found").
+			AddOp(op)
+	}
+
+	if errMsg[0] == '"' {
+		errMsg = errMsg[1:]
+	}
+
+	if errMsg[len(errMsg)-1] == '"' {
+		errMsg = errMsg[:len(errMsg)-1]
+	}
+
+	// extract the new error name from message: "FileNotFound: a file with name %s was not found" => "FileNotFound"
+	split := strings.Split(errMsg, ":")
+
+	// extract the error name from the message
+	errName := strings.TrimSpace(split[0])
+
+	if errName == "" {
+		return "", grr.Errorf("NoErrorName: error name not found in error message")
+	}
+
+	// extract the error message from the message
+	errMsg = strings.TrimSpace(strings.Join(split[1:], ""))
+
+	var buf strings.Builder
+
+	err := tmplGet.Execute(&buf, TemplateData{
+		ErrName: errName,
+		Vars:    args,
+		Message: errMsg,
+	})
+
+	if err != nil {
+		return "", grr.Errorf("FailedToExecuteTemplate: something went wrong while generating").
+			AddError(err).
+			AddTrait(TrIsInternal, "true").
+			AddOp(op)
+	}
+
+	return buf.String(), nil
+}