🔄 Sync from monorepo

wearemojo/mojo@c8fad2a

lib/cher/error.go

@@ -8,6 +8,7 @@ import (
 	"slices"
 
 	"github.com/pkg/errors"
+	"github.com/wearemojo/mojo-public-go/lib/stacktrace"
 )
 
 // errors that are expected to be common across services
@@ -32,16 +33,24 @@ const (
 
 // E implements the official CHER structure
 type E struct {
-	Code    string `json:"code"`
-	Meta    M      `json:"meta,omitempty"`
-	Reasons []E    `json:"reasons,omitempty"`
+	Code    string             `json:"code"`
+	Meta    M                  `json:"meta,omitempty"`
+	stack   []stacktrace.Frame `json:"-"`
+	Reasons []E                `json:"reasons,omitempty"`
 }
 
 // New returns a new E structure with code, meta, and optional reasons.
 func New(code string, meta M, reasons ...E) E {
+	// For errors with only one reason, we can merge stack traces so we can actually see where the error originally came from
+	stack := stacktrace.GetCallerFrames(2)
+	if len(reasons) == 1 {
+		rootStack := reasons[0].stack
+		stack = stacktrace.MergeStacks(rootStack, stack)
+	}
 	return E{
 		Code:    code,
 		Meta:    meta,
+		stack:   stack,
 		Reasons: reasons,
 	}
 }
@@ -103,6 +112,10 @@ func (e E) Serialize() string {
 	return string(output)
 }
 
+func (e E) GetStack() []stacktrace.Frame {
+	return e.stack
+}
+
 // M it an alias type for map[string]any
 type M map[string]any
 

lib/merr/merr.go

@@ -16,6 +16,10 @@ var _ interface {
 	Unwrap() []error
 } = E{}
 
+type StackError interface {
+	GetStack() []stacktrace.Frame
+}
+
 // Merrer (merr-er) represents a merr-compatible error
 //
 // It primarily exists to allow `Wrap` to return nil without forcing us to use
@@ -47,15 +51,22 @@ func New(ctx context.Context, code Code, meta M, reasons ...error) E {
 			panic("merr.New: nil reason provided for " + code.String())
 		}
 	}
-
+	stack := stacktrace.GetCallerFrames(2)
+	// For errors with only one reason, we can merge stack traces so we can actually see where the error originally came from
+	if len(reasons) == 1 {
+		if stackErr, ok := reasons[0].(StackError); ok {
+			rootStack := stackErr.GetStack()
+			stack = stacktrace.MergeStacks(rootStack, stack)
+		}
+	}
 	return E{
 		Code: code,
 		Meta: meta,
 
 		TraceID: spanContext.TraceID(),
 		SpanID:  spanContext.SpanID(),
 
-		Stack: stacktrace.GetCallerFrames(2),
+		Stack: stack,
 
 		Reasons: reasons,
 	}
@@ -122,3 +133,7 @@ func (e E) Is(err error) bool {
 func (e E) Unwrap() []error {
 	return e.Reasons
 }
+
+func (e E) GetStack() []stacktrace.Frame {
+	return e.Stack
+}

lib/middleware/request/logger.go

@@ -118,7 +118,12 @@ func Logger(log *logrus.Entry) func(http.Handler) http.Handler {
 				if mErr, ok := gerrors.As[merr.E](err); ok {
 					fn(ctx, mErr)
 				} else if cErr, ok := gerrors.As[cher.E](err); ok {
-					fn(ctx, merr.New(ctx, merr.Code(cErr.Code), merr.M(cErr.Meta), slicefn.Map(cErr.Reasons, func(r cher.E) error { return r })...))
+					reasons := slicefn.Map(cErr.Reasons, func(r cher.E) error { return r })
+					// If the cher error has no reasons, add the cher error itself
+					if len(reasons) == 0 {
+						reasons = append(reasons, cErr)
+					}
+					fn(ctx, merr.New(ctx, merr.Code(cErr.Code), merr.M(cErr.Meta), reasons...))
 				} else {
 					fn(ctx, merr.New(ctx, "unexpected_request_failure", nil, err))
 				}

lib/stacktrace/frames.go

@@ -60,3 +60,29 @@ func FormatFrames(frames []Frame) string {
 
 	return sb.String()
 }
+
+// insert will put frame u into slice s at index at
+func insert(s []Frame, u Frame, at int) []Frame {
+	return append(s[:at], append([]Frame{u}, s[at:]...)...)
+}
+
+func MergeStacks(root []Frame, wrapped []Frame) []Frame {
+	if len(wrapped) == 0 {
+		return root
+	}
+	if len(wrapped) == 1 {
+		return append(root, wrapped[0])
+	}
+
+	for idx, f := range root {
+		if f == wrapped[0] {
+			// root already contains the first frame of wrapped
+			return root
+		}
+		if f == wrapped[1] {
+			// Insert the first frame into the stack if the second frame is found
+			return insert(root, wrapped[0], idx)
+		}
+	}
+	return root
+}

lib/stacktrace/frames_test.go

@@ -65,3 +65,51 @@ func TestFormatFrames(t *testing.T) {
 
 	is.Equal(FormatFrames(frames), expectedFormat)
 }
+
+func TestMergeFrames(t *testing.T) {
+	is := is.New(t)
+
+	root := []Frame{
+		{
+			File:     "/lib/foo/foo.go",
+			Line:     123,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.doFoo",
+		},
+		{
+			File:     "/lib/foo/bar.go",
+			Line:     456,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.barThing",
+		},
+	}
+
+	wrapped := []Frame{
+		{
+			File:     "/lib/foo/baz.go",
+			Line:     789,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.bazThing",
+		},
+		{
+			File:     "/lib/foo/foo.go",
+			Line:     123,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.doFoo",
+		},
+	}
+
+	is.Equal(MergeStacks(root, wrapped), []Frame{
+		{
+			File:     "/lib/foo/baz.go",
+			Line:     789,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.bazThing",
+		},
+		{
+			File:     "/lib/foo/foo.go",
+			Line:     123,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.doFoo",
+		},
+		{
+			File:     "/lib/foo/bar.go",
+			Line:     456,
+			Function: "github.com/wearemojo/mojo-public-go/lib/foo.barThing",
+		},
+	})
+}