From 8aa14098e2f1910ff7787221460aa53f7747c1f1 Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 17:37:19 +0800
Subject: [PATCH 1/6] feat:

---
 errors.go | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/errors.go b/errors.go
index 161aea25..13887572 100644
--- a/errors.go
+++ b/errors.go
@@ -67,10 +67,9 @@
 //
 // New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
 // invoked. This information can be retrieved with the following interface:
-//
-//     type stackTracer interface {
-//             StackTrace() errors.StackTrace
-//     }
+type stackTracer interface {
+        StackTrace() errors.StackTrace
+}
 //
 // The returned errors.StackTrace type is defined as
 //
@@ -106,6 +105,23 @@ func New(message string) error {
 	}
 }
 
+// ExistStack return an error already with stack
+// ExistStack will check all parent error
+func ExistStack(err error) bool {
+	type stackTracer interface {
+		StackTrace() StackTrace
+	}
+	if _, ok := err.(stackTracer); ok {
+		return true
+	}
+	type causer interface {
+		Cause() error
+	}
+	if _, ok := err.(causer); !ok {
+		return false
+	}
+	return ExistStack(err.Cause())
+}
 // Errorf formats according to a format specifier and returns the string
 // as a value that satisfies error.
 // Errorf also records the stack trace at the point it was called.

From b3e14fafbaa846b3accea2fd58f36f80d65f4ffb Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 17:57:27 +0800
Subject: [PATCH 2/6] feat func ExistStack(err error) bool:

non-intrusive:
Add a public method to determine if the error has been appended to the stack.
Avoid adding the stack repeatedly for errors.
---
 errors.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/errors.go b/errors.go
index 13887572..d2a53998 100644
--- a/errors.go
+++ b/errors.go
@@ -67,9 +67,10 @@
 //
 // New, Errorf, Wrap, and Wrapf record a stack trace at the point they are
 // invoked. This information can be retrieved with the following interface:
-type stackTracer interface {
-        StackTrace() errors.StackTrace
-}
+//
+//     type stackTracer interface {
+//             StackTrace() errors.StackTrace
+//     }
 //
 // The returned errors.StackTrace type is defined as
 //

From 5969e207acfa8ce13b87c2333185580af9e34730 Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 18:22:34 +0800
Subject: [PATCH 3/6] fix: error method

---
 errors.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/errors.go b/errors.go
index d2a53998..e1bf4dc3 100644
--- a/errors.go
+++ b/errors.go
@@ -118,10 +118,11 @@ func ExistStack(err error) bool {
 	type causer interface {
 		Cause() error
 	}
-	if _, ok := err.(causer); !ok {
+	if value, ok := err.(causer); ok {
+		return ExistStack(err.Cause())
+	} else {
 		return false
 	}
-	return ExistStack(err.Cause())
 }
 // Errorf formats according to a format specifier and returns the string
 // as a value that satisfies error.

From 88c8636aea339f9c77a2eae2ee8cb951038616f1 Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 18:24:48 +0800
Subject: [PATCH 4/6] feat: test ExistStack

add ExistStack test
---
 errors_test.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/errors_test.go b/errors_test.go
index 2089b2f7..6b0b6db9 100644
--- a/errors_test.go
+++ b/errors_test.go
@@ -27,6 +27,23 @@ func TestNew(t *testing.T) {
 	}
 }
 
+func TestExistStack(t *testing.T) {
+	tests := []struct {
+		err  error
+		want bool
+	}{
+		{io.EOF, false},
+		{Wrap(io.EOF, "read error"), true},
+	}
+
+	for _, tt := range tests {
+		got := ExistStack(tt.err)
+		if got != tt.want {
+			t.Errorf("ExistStack(%v): got: %v, want %v", tt.err, got, tt.want)
+		}
+	}
+}
+
 func TestWrapNil(t *testing.T) {
 	got := Wrap(nil, "no error")
 	if got != nil {

From 0247cb8ef2bcd9f1bd901c642de4dc6b9ef2eb70 Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 18:56:34 +0800
Subject: [PATCH 5/6] fix: error variable name

---
 errors.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/errors.go b/errors.go
index e1bf4dc3..4a828209 100644
--- a/errors.go
+++ b/errors.go
@@ -119,7 +119,7 @@ func ExistStack(err error) bool {
 		Cause() error
 	}
 	if value, ok := err.(causer); ok {
-		return ExistStack(err.Cause())
+		return ExistStack(value.Cause())
 	} else {
 		return false
 	}

From 5c191f96b9c4670a8c0332d4effe70f5ffcfb1bb Mon Sep 17 00:00:00 2001
From: wbflooksky <52812629+wbflooksky@users.noreply.github.com>
Date: Wed, 19 May 2021 19:01:18 +0800
Subject: [PATCH 6/6] style: optimizing code structure

---
 errors.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/errors.go b/errors.go
index 4a828209..84bade4b 100644
--- a/errors.go
+++ b/errors.go
@@ -123,6 +123,11 @@ func ExistStack(err error) bool {
 	} else {
 		return false
 	}
+	cause, ok := err.(causer)
+        if !ok {
+                return false
+        }
+        return ExistStack(cause.Cause())
 }
 // Errorf formats according to a format specifier and returns the string
 // as a value that satisfies error.