From 34a01c627946349a120fa036956ba81b585c7587 Mon Sep 17 00:00:00 2001
From: Theta-Dev <t.testboy@gmail.com>
Date: Sun, 17 Oct 2021 10:59:33 +0200
Subject: [PATCH] Pass through try-compatible errors

---
 try/try.go      | 11 +++++++++--
 try/try_test.go | 16 ++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/try/try.go b/try/try.go
index a54c6e6..f24576b 100644
--- a/try/try.go
+++ b/try/try.go
@@ -47,7 +47,14 @@ type call struct {
 }
 
 // FromErr wraps a standard error into a try-compatible one with extended stack info.
-func FromErr(err error) *tryErr {
+func FromErr(err error) Err {
+	// If the error is already try-compatible, return
+	//nolint:errorlint
+	cterr, ok := err.(Err)
+	if ok {
+		return cterr
+	}
+
 	terr := &tryErr{err: err, callStack: []call{}}
 
 	pc, _, _, ok := runtime.Caller(0)
@@ -82,7 +89,7 @@ func FromErr(err error) *tryErr {
 }
 
 // NewErr creates a new try-compatible error with extended stack info.
-func NewErr(msg string) *tryErr {
+func NewErr(msg string) Err {
 	return FromErr(errors.New(msg))
 }
 
diff --git a/try/try_test.go b/try/try_test.go
index ad26fa7..fac96ee 100644
--- a/try/try_test.go
+++ b/try/try_test.go
@@ -220,6 +220,22 @@ func TestReturnStd(t *testing.T) {
 	}
 }
 
+func TestCheckTryErr(t *testing.T) {
+	testErr := NewErr("TestErr")
+
+	tf := func() (err Err) {
+		defer Return(&err)
+		Check(testErr)
+		return
+	}
+
+	err := tf()
+
+	if err != testErr {
+		t.Fail()
+	}
+}
+
 func ExampleReturn() {
 	var err Err
 	defer Return(&err)