improve annotations

gotry_generate/main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bufio"
-	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -26,8 +25,8 @@ type line struct {
 	Types     []string
 }
 
-func parseDefinitions(defFileName string, outFileName string) (err error) {
+func parseDefinitions(defFileName string, outFileName string) (err try.TryErr) {
-	defer try.Annotate("error parsing definitions", &err)
+	defer try.Annotate(&err, "error parsing definitions")
 
 	defFile := try.File(os.Open(defFileName))
 
@@ -78,12 +77,12 @@ func parseDefinitions(defFileName string, outFileName string) (err error) {
 	return
 }
 
-func parseLine(lineStr string, imports map[string]bool) (*line, error) {
+func parseLine(lineStr string, imports map[string]bool) (*line, try.TryErr) {
 	lineParts := strings.Split(lineStr, ";")
 	lineData := line{}
 
 	if len(lineParts) < 2 {
-		return nil, errors.New("missing type name")
+		return nil, try.NewErr("missing type name")
 	}
 
 	// Parse variable name
@@ -92,7 +91,7 @@ func parseLine(lineStr string, imports map[string]bool) (*line, error) {
 		lineData.Name = match[1]
 		lineData.WithSlice = match[2] != ""
 	} else {
-		return nil, errors.New("invalid variable name")
+		return nil, try.NewErr("invalid variable name")
 	}
 
 	// Parse type name(s)
@@ -103,7 +102,7 @@ func parseLine(lineStr string, imports map[string]bool) (*line, error) {
 		}
 	}
 	if len(lineData.Types) == 0 {
-		return nil, errors.New("invalid type name")
+		return nil, try.NewErr("invalid type name")
 	}
 
 	// Parse imports
@@ -115,7 +114,7 @@ func parseLine(lineStr string, imports map[string]bool) (*line, error) {
 	return &lineData, nil
 }
 
-func copyLibrary(targetDir string, noTests, noStds bool) (caught error) {
+func copyLibrary(targetDir string, noTests, noStds bool) (caught try.TryErr) {
 	defer try.Return(&caught)
 
 	filesToCopy := []string{"try.go"}
@@ -144,14 +143,6 @@ func copyLibrary(targetDir string, noTests, noStds bool) (caught error) {
 		try.Check(dest.Close())
 	}
 
-	// Add go-generate command
-	gencmd := "\n//go:generate go run code.thetadev.de/ThetaDev/gotry/gotry_generate " +
-		"-def types.csv -o .\n"
-	f := try.File(
-		os.OpenFile(filepath.Join(targetDir, "try.go"), os.O_APPEND|os.O_WRONLY, 0o644))
-	try.Empty(f.WriteString(gencmd))
-	try.Check(f.Close())
-
 	// If not present, add definition file template
 	definitionFile := filepath.Join(targetDir, "types.csv")
 
@@ -170,7 +161,7 @@ func goFmt(goFile string) error {
 }
 
 func main() {
-	defer try.Catch(func(err error) {
+	defer try.Catch(func(err try.TryErr) {
 		fmt.Println("Error: " + err.Error())
 	})
 

try/std_types_test.go

@@ -15,7 +15,7 @@ func TestStrHelper_noThrow(t *testing.T) {
 }
 
 func TestStrHelper_throw(t *testing.T) {
-	var err error
+	var err TryErr
 	defer Return(&err)
 
 	String(throw())
@@ -31,8 +31,8 @@ func TestStrStrHelper(t *testing.T) {
 }
 
 func Example_copyFile() {
-	copyFile := func(src, dst string) (err error) {
+	copyFile := func(src, dst string) (err TryErr) {
-		defer Returnf(&err, "copy %s %s", src, dst)
+		defer Annotate(&err, fmt.Sprintf("copy %s %s", src, dst))
 
 		// These helpers are as fast as Check() calls
 		r := File(os.Open(src))

try/try.go

@@ -9,9 +9,118 @@ https://github.com/lainio/err2
 import (
 	"errors"
 	"fmt"
+	"regexp"
+	"runtime"
 	"runtime/debug"
+	"strings"
 )
 
+// TryErr is an interface for an error with extended stack info.
+type TryErr interface {
+	Error() string
+	Unwrap() error
+	CallStack() []call
+	CallStackString() string
+	PrintCallStack()
+	GetData() *tryErrData
+	Annotate(msg string)
+}
+
+// tryErrObj is an extended error struct.
+type tryErrObj struct {
+	err         error
+	annotations []string
+	callStack   []call
+}
+
+// tryErrData is exported error data. Can be converted to JSON.
+type tryErrData struct {
+	Msg         string   `json:"msg"`
+	Annotations []string `json:"annotations"`
+	CallStack   []call   `json:"call_stack"`
+}
+
+type call struct {
+	Function string `json:"fn"`
+	Line     int    `json:"l"`
+}
+
+func newErr(err error) *tryErrObj {
+	terr := &tryErrObj{err: err, callStack: []call{}}
+
+	pc, _, _, ok := runtime.Caller(0)
+	if !ok {
+		return terr
+	}
+	thisFnc := runtime.FuncForPC(pc)
+	if thisFnc == nil {
+		return terr
+	}
+
+	rexp := regexp.MustCompile(`.+\/`)
+	thisPkg := rexp.FindString(thisFnc.Name())
+
+	for i := 1; ; i++ {
+		pc, f, l, ok := runtime.Caller(i)
+
+		if !ok {
+			break
+		}
+
+		fnc := runtime.FuncForPC(pc).Name()
+
+		if strings.HasPrefix(fnc, thisPkg) && !strings.HasSuffix(f, "_test.go") {
+			continue
+		}
+
+		terr.callStack = append(terr.callStack, call{Line: l, Function: fnc})
+	}
+
+	return terr
+}
+
+func NewErr(msg string) *tryErrObj {
+	return newErr(errors.New(msg))
+}
+
+func (e *tryErrObj) Error() string {
+	msgs := e.annotations
+	msgs = append(msgs, e.err.Error())
+	return strings.Join(msgs, ": ")
+}
+
+func (e *tryErrObj) Unwrap() error {
+	return e.err
+}
+
+func (e *tryErrObj) CallStack() []call {
+	return e.callStack
+}
+
+func (e *tryErrObj) CallStackString() string {
+	res := fmt.Sprintf("ERROR: %s\n", e.err.Error())
+	for _, c := range e.callStack {
+		res += fmt.Sprintf("%s:%d\n", c.Function, c.Line)
+	}
+	return res
+}
+
+func (e *tryErrObj) PrintCallStack() {
+	fmt.Println(e.CallStackString())
+}
+
+func (e *tryErrObj) GetData() *tryErrData {
+	return &tryErrData{
+		Msg:         e.err.Error(),
+		CallStack:   e.callStack,
+		Annotations: e.annotations,
+	}
+}
+
+func (e *tryErrObj) Annotate(msg string) {
+	e.annotations = append(e.annotations, msg)
+}
+
 // Empty is a helper method to handle errors of func() (string, error) functions.
 func Empty(_ interface{}, err error) {
 	Check(err)
@@ -30,7 +139,7 @@ func Any(args ...interface{}) []interface{} {
 // {return err} on happy path.
 func Check(err error) {
 	if err != nil {
-		panic(err)
+		panic(newErr(err))
 	}
 }
 
@@ -45,7 +154,7 @@ func check(args []interface{}) {
 		if !ok {
 			panic("wrong signature")
 		}
-		panic(err)
+		panic(newErr(err))
 	}
 }
 
@@ -53,7 +162,7 @@ func check(args []interface{}) {
 // functions returning errors them self. For those functions that doesn't
 // return errors there is a Catch function. Note! The handler function f is
 // called only when err != nil.
-func Handle(err *error, f func()) {
+func Handle(err *TryErr, f func()) {
 	// This and Catch are similar but we need to call recover() here because
 	// how it works with defer. We cannot refactor these to use same function.
 
@@ -69,42 +178,25 @@ func Handle(err *error, f func()) {
 		if *err != nil {
 			f()
 		}
-	case error:
+	case TryErr:
 		// We or someone did transport this error thru panic.
-		*err = r.(error)
+		*err = r.(TryErr)
 		f()
 	default:
 		panic(r)
 	}
 }
 
-// Returnf wraps an error. It's similar to fmt.Errorf, but it's called only if
-// error != nil.
-func Returnf(err *error, format string, args ...interface{}) {
-	// This and Handle are similar but we need to call recover here because how
-	// it works with defer. We cannot refactor these two to use same function.
-
-	if r := recover(); r != nil {
-		e, ok := r.(error)
-		if !ok {
-			panic(r) // Not ours, carry on panicking
-		}
-		*err = fmt.Errorf(format+": %v", append(args, e)...)
-	} else if *err != nil { // if other handlers call recovery() we still..
-		*err = fmt.Errorf(format+": %v", append(args, *err)...)
-	}
-}
-
 // Catch is a convenient helper to those functions that doesn't return errors.
 // Go's main function is a good example. Note! There can be only one deferred
 // Catch function per non error returning function. See Handle for more
 // information.
-func Catch(f func(err error)) {
+func Catch(f func(err TryErr)) {
 	// This and Handle are similar but we need to call recover here because how
 	// it works with defer. We cannot refactor these 2 to use same function.
 
 	if r := recover(); r != nil {
-		e, ok := r.(error)
+		e, ok := r.(TryErr)
 		if !ok {
 			panic(r)
 		}
@@ -114,12 +206,12 @@ func Catch(f func(err error)) {
 
 // CatchAll is a helper function to catch and write handlers for all errors and
 // all panics thrown in the current go routine.
-func CatchAll(errorHandler func(err error), panicHandler func(v interface{})) {
+func CatchAll(errorHandler func(err TryErr), panicHandler func(v interface{})) {
 	// This and Handle are similar but we need to call recover here because how
 	// it works with defer. We cannot refactor these 2 to use same function.
 
 	if r := recover(); r != nil {
-		e, ok := r.(error)
+		e, ok := r.(TryErr)
 		if ok {
 			errorHandler(e)
 		} else {
@@ -131,12 +223,12 @@ func CatchAll(errorHandler func(err error), panicHandler func(v interface{})) {
 // CatchTrace is a helper function to catch and handle all errors. It recovers a
 // panic as well and prints its call stack. This is preferred helper for go
 // workers on long running servers.
-func CatchTrace(errorHandler func(err error)) {
+func CatchTrace(errorHandler func(err TryErr)) {
 	// This and Handle are similar but we need to call recover here because how
 	// it works with defer. We cannot refactor these 2 to use same function.
 
 	if r := recover(); r != nil {
-		e, ok := r.(error)
+		e, ok := r.(TryErr)
 		if ok {
 			errorHandler(e)
 		} else {
@@ -149,12 +241,12 @@ func CatchTrace(errorHandler func(err error)) {
 // Return is same as Handle but it's for functions which don't wrap or annotate
 // their errors. If you want to annotate errors see Annotate for more
 // information.
-func Return(err *error) {
+func Return(err *TryErr) {
 	// This and Handle are similar but we need to call recover here because how
 	// it works with defer. We cannot refactor these two to use same function.
 
 	if r := recover(); r != nil {
-		e, ok := r.(error)
+		e, ok := r.(TryErr)
 		if !ok {
 			panic(r) // Not ours, carry on panicking
 		}
@@ -165,20 +257,18 @@ func Return(err *error) {
 // Annotate is for annotating an error. It's similar to Returnf but it takes only
 // two arguments: a prefix string and a pointer to error. It adds ": " between
 // the prefix and the error text automatically.
-func Annotate(prefix string, err *error) {
+func Annotate(err *TryErr, msg string) {
 	// This and Handle are similar but we need to call recover here because how
 	// it works with defer. We cannot refactor these two to use same function.
 
 	if r := recover(); r != nil {
-		e, ok := r.(error)
+		e, ok := r.(TryErr)
 		if !ok {
 			panic(r) // Not ours, carry on panicking
 		}
 		*err = e
-		format := prefix + ": " + e.Error()
+		e.Annotate(msg)
-		*err = errors.New(format)
 	} else if *err != nil { // if other handlers call recovery() we still..
-		format := prefix + ": " + (*err).Error()
+		(*err).Annotate(msg)
-		*err = errors.New(format)
 	}
 }

try/try_test.go

@@ -8,6 +8,7 @@ https://github.com/lainio/err2
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 )
 
@@ -64,7 +65,7 @@ func TestAny_noError(t *testing.T) {
 }
 
 func TestDefault_Error(t *testing.T) {
-	var err error
+	var err TryErr
 	defer Return(&err)
 
 	Any(throw())
@@ -73,7 +74,7 @@ func TestDefault_Error(t *testing.T) {
 }
 
 func TestAny_Error(t *testing.T) {
-	var err error
+	var err TryErr
 	defer Handle(&err, func() {})
 
 	Any(throw())
@@ -82,7 +83,7 @@ func TestAny_Error(t *testing.T) {
 }
 
 func panickingHandle() {
-	var err error
+	var err TryErr
 	defer Handle(&err, func() {})
 
 	Any(wrongSignature())
@@ -98,7 +99,7 @@ func TestPanickingCarryOn_Handle(t *testing.T) {
 }
 
 func panickingCatchAll() {
-	defer CatchAll(func(err error) {}, func(v interface{}) {})
+	defer CatchAll(func(err TryErr) {}, func(v interface{}) {})
 
 	Any(wrongSignature())
 }
@@ -113,7 +114,7 @@ func TestPanickingCatchAll(t *testing.T) {
 }
 
 func panickingCatchTrace() {
-	defer CatchTrace(func(err error) {})
+	defer CatchTrace(func(err TryErr) {})
 
 	Any(wrongSignature())
 }
@@ -128,7 +129,7 @@ func TestPanickingCatchTrace(t *testing.T) {
 }
 
 func panickingReturn() {
-	var err error
+	var err TryErr
 	defer Return(&err)
 
 	Any(wrongSignature())
@@ -144,7 +145,7 @@ func TestPanicking_Return(t *testing.T) {
 }
 
 func panickingCatch() {
-	defer Catch(func(err error) {})
+	defer Catch(func(err TryErr) {})
 
 	Any(wrongSignature())
 }
@@ -159,7 +160,7 @@ func TestPanicking_Catch(t *testing.T) {
 }
 
 func TestCatch_Error(t *testing.T) {
-	defer Catch(func(err error) {
+	defer Catch(func(err TryErr) {
 		// fmt.Printf("error and defer handling:%s\n", err)
 	})
 
@@ -169,15 +170,15 @@ func TestCatch_Error(t *testing.T) {
 }
 
 func ExampleReturn() {
-	var err error
+	var err TryErr
 	defer Return(&err)
 	Any(noThrow())
 	// Output:
 }
 
 func ExampleAnnotate() {
-	annotated := func() (err error) {
+	annotated := func() (err TryErr) {
-		defer Annotate("annotated", &err)
+		defer Annotate(&err, "annotated")
 		Any(throw())
 		return err
 	}
@@ -186,33 +187,22 @@ func ExampleAnnotate() {
 	// Output: annotated: this is an ERROR
 }
 
-func ExampleReturnf() {
-	annotated := func() (err error) {
-		defer Returnf(&err, "annotated: %s", "err2")
-		Any(throw())
-		return err
-	}
-	err := annotated()
-	fmt.Printf("%v", err)
-	// Output: annotated: err2: this is an ERROR
-}
-
 func ExampleAnnotate_deferStack() {
-	annotated := func() (err error) {
+	annotated := func() (err TryErr) {
-		defer Annotate("annotated 2nd", &err)
+		defer Annotate(&err, "annotated 2nd")
-		defer Annotate("annotated 1st", &err)
+		defer Annotate(&err, "annotated 1st")
 		Any(throw())
 		return err
 	}
 	err := annotated()
 	fmt.Printf("%v", err)
-	// Output: annotated 2nd: annotated 1st: this is an ERROR
+	// Output: annotated 1st: annotated 2nd: this is an ERROR
 }
 
 func ExampleHandle() {
-	doSomething := func(a, b int) (err error) {
+	doSomething := func(a, b int) (err TryErr) {
 		defer Handle(&err, func() {
-			err = fmt.Errorf("error with (%d, %d): %w", a, b, err)
+			err.Annotate(fmt.Sprintf("error with (%d, %d)", a, b))
 		})
 		Any(throw())
 		return err
@@ -278,3 +268,44 @@ func BenchmarkRecursionWithErrorCheck_NotRelated(b *testing.B) {
 		}
 	}
 }
+
+func TestNewTryErr(t *testing.T) {
+	tryErr := NewErr("I f*cked up")
+	callStack := tryErr.CallStackString()
+
+	if !strings.HasPrefix(callStack, "ERROR: I f*cked up\n") {
+		fmt.Println("Call stack does not have prefix.\n" + callStack)
+		t.Fail()
+	}
+
+	if strings.Count(callStack, "\n") != 4 {
+		fmt.Println("Call stack is not 4 lines long.\n" + callStack)
+		t.Fail()
+	}
+}
+
+func TestGetData(t *testing.T) {
+	tryErr := NewErr("I f*cked up")
+	tryErr.Annotate("test1")
+	tryErr.Annotate("test2")
+	data := tryErr.GetData()
+
+	if data.Msg != "I f*cked up" {
+		fmt.Println("wrong msg")
+		t.Fail()
+	}
+
+	if data.Annotations[0] != "test1" {
+		fmt.Println("wrong annotation#0")
+		t.Fail()
+	}
+	if data.Annotations[1] != "test2" {
+		fmt.Println("wrong annotation#1")
+		t.Fail()
+	}
+
+	if len(data.CallStack) != 3 {
+		fmt.Println("call stack length != 3, " + fmt.Sprint(len(data.CallStack)))
+		t.Fail()
+	}
+}