From 653e6c2b26cbb38c92b4b6af5de4d5f60363f7f2 Mon Sep 17 00:00:00 2001
From: Bigyin <sergei.aparin1955@yandex.ru>
Date: Mon, 16 Mar 2020 01:15:23 +0300
Subject: [PATCH 1/2] Add RootMessage function

---
 cause.go      | 38 ++++++++++++++++++++++++++++++++++++++
 cause_test.go | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/cause.go b/cause.go
index 1e2df9f..286a5a1 100644
--- a/cause.go
+++ b/cause.go
@@ -24,3 +24,41 @@ func RootCause(err error) error {
 		err = st.cause
 	}
 }
+
+/*
+RootMessage returns message which was associated with root cause error.
+	func f(file string) error {
+		....
+		....
+		file, err := os.Open(file)
+		if err != nil {
+			return stacktrace.Propagate(err, "formatted message for user", ...specific args)
+		}
+		....
+		....
+	}
+
+	err := f("./foo/bar")
+	if err != nil {
+		err := stacktrace.RootCause(err)
+		// do something with root error
+
+		// return formatted message for user
+		showToUser(stacktrace.RootMessage(err))
+	}
+
+*/
+func RootMessage(err error) string {
+	var message string
+	for {
+		st, ok := err.(*stacktrace)
+		if !ok {
+			return message
+		}
+		if st.cause == nil {
+			return st.message
+		}
+		err = st.cause
+		message = st.message
+	}
+}
diff --git a/cause_test.go b/cause_test.go
index f63a71b..f24132f 100644
--- a/cause_test.go
+++ b/cause_test.go
@@ -46,3 +46,37 @@ func TestRootCause(t *testing.T) {
 		assert.Equal(t, test.rootCause, stacktrace.RootCause(test.err))
 	}
 }
+
+func TestRootMessage(t *testing.T) {
+	for _, test := range []struct {
+		message string
+		err     error
+	}{
+		{
+			message: "",
+			err:     nil,
+		},
+		{
+			message: "",
+			err:     customError("msg"),
+		},
+		{
+			message: "",
+			err:     errors.New("msg"),
+		},
+		{
+			message: "msg",
+			err:     stacktrace.NewError("msg"),
+		},
+		{
+			message: "msg2",
+			err:     stacktrace.Propagate(customError("msg1"), "msg2"),
+		},
+		{
+			message: "msg2",
+			err:     stacktrace.Propagate(errors.New("msg1"), "msg2"),
+		},
+	} {
+		assert.Equal(t, test.message, stacktrace.RootMessage(test.err))
+	}
+}

From f758a2ddeae955f62d7170462647b9e593e50c07 Mon Sep 17 00:00:00 2001
From: Bigyin <sergei.aparin1955@yandex.ru>
Date: Mon, 16 Mar 2020 02:42:30 +0300
Subject: [PATCH 2/2] Updated travis.yml

---
 .travis.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index fc3d7eb..10d6f90 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,14 +2,14 @@ sudo: false
 
 language: go
 
-go: 1.6
+go: 1.13
 
 before_install:
-  - go get github.com/golang/lint/golint
+  - go get -u golang.org/x/lint/golint
 
 script:
   - go vet ./...
-  - $HOME/gopath/bin/golint ./...
+  - $GOPATH/bin/golint ./...
   - go test -v ./...
 
 notifications: