[AU-217] Make NCError implement StackTracer interface from aws-xray-sdk-go

errors/error.go

@@ -3,6 +3,8 @@ package errors
 import (
 	"fmt"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 type LogSeverity string
@@ -73,6 +75,8 @@ type NCError struct {
 	// Contains stack trace from the initial place when the error
 	// was raised.
 	Stack []string
+	// Raw stack trace in the form of program counters, as returned by the runtime.Callers
+	RawStack *stack
 	//The root error at the base level.
 	RootError error
 }
@@ -85,6 +89,12 @@ func (n NCError) Error() string {
 	return strings.Join(messages, ": ")
 }
 
+// StackTrace returns github.com/pkg/errors stack trace. This is to implement interface from aws-xray-sdk-go
+// for passing along stack traces to X-Ray to segments.
+func (n NCError) StackTrace() errors.StackTrace {
+	return n.RawStack.StackTrace()
+}
+
 // New error with context.
 func New(message string, fields Fields) error {
 	fileName, funcName, lineNumber := GetRuntimeContext()
@@ -95,9 +105,12 @@ func New(message string, fields Fields) error {
 		FileName: fileName,
 		Line:     lineNumber,
 		Severity: ERROR}
+	stack, rawStack := getStackTraces()
 	return NCError{
-		Causes: []Cause{newCause},
-		Stack:  GetTrace()}
+		Causes:   []Cause{newCause},
+		Stack:    stack,
+		RawStack: rawStack,
+	}
 }
 
 func NewWithSeverity(message string, fields Fields, severity LogSeverity) error {
@@ -110,9 +123,11 @@ func NewWithSeverity(message string, fields Fields, severity LogSeverity) error
 		Line:     lineNumber,
 		Severity: severity,
 	}
+	stack, rawStack := getStackTraces()
 	return NCError{
-		Causes: []Cause{newCause},
-		Stack:  GetTrace(),
+		Causes:   []Cause{newCause},
+		Stack:    stack,
+		RawStack: rawStack,
 	}
 }
 
@@ -135,9 +150,11 @@ func WithContext(err error, message string, fields Fields) error {
 		return ncError
 	}
 
+	stack, rawStack := getStackTraces()
 	return NCError{
 		Causes:    []Cause{newCause, Cause{Message: err.Error()}},
-		Stack:     GetTrace(),
+		Stack:     stack,
+		RawStack:  rawStack,
 		RootError: err}
 }
 
@@ -160,9 +177,11 @@ func WithContextAndSeverity(err error, message string, severity LogSeverity, fie
 		return ncError
 	}
 
+	stack, rawStack := getStackTraces()
 	return NCError{
 		Causes:    []Cause{newCause, Cause{Message: err.Error()}},
-		Stack:     GetTrace(),
+		Stack:     stack,
+		RawStack:  rawStack,
 		RootError: err,
 	}
 }

errors/stack_trace.go

@@ -5,26 +5,35 @@ import (
 	"regexp"
 	"runtime"
 	"strings"
+
+	"github.com/pkg/errors"
 )
 
 var (
 	regexFuncName = regexp.MustCompile(`(([^/]+/)+)?([^/.]+)((\.[^/.]+)+)?`)
 )
 
-// GetTrace return the simplified stack trace in the format file_name(func_name):line. It also contains the current goroutine entrypoint.
-func GetTrace() []string {
-	var stack []string
+// getStackTraces returns custom-formatted and raw (in the form of program counters) stack trace
+// for the purpose of initializing NCError struct
+func getStackTraces() ([]string, *stack) {
+	var formattedStack []string
 	callStack := *callers()
 	st := callStack[:len(callStack)-1]
 	for _, f := range st {
 		frame := frame(f)
-		stack = append(stack, frame.formatContext())
+		formattedStack = append(formattedStack, frame.formatContext())
 	}
 
+	return formattedStack, &callStack
+}
+
+// GetTrace return the simplified stack trace in the format file_name(func_name):line. It also contains the current goroutine entrypoint.
+func GetTrace() []string {
+	stack, _ := getStackTraces()
+
 	return stack
 }
 
-type stack []uintptr
 type frame uintptr
 
 func (f frame) pc() uintptr { return uintptr(f) - 1 }
@@ -71,6 +80,16 @@ func GetRuntimeContext() (fileName, funcName string, line int) {
 	return
 }
 
+type stack []uintptr
+
+func (s *stack) StackTrace() errors.StackTrace {
+	f := make([]errors.Frame, len(*s))
+	for i := 0; i < len(f); i++ {
+		f[i] = errors.Frame((*s)[i])
+	}
+	return f
+}
+
 func callers() *stack {
 	const depth = 32
 	var pcs [depth]uintptr