From 0ef9c39b4387cfd7cd70731d59abad4171f74473 Mon Sep 17 00:00:00 2001
From: Wonyoung Ju <getogrand@gmail.com>
Date: Sat, 28 Jul 2018 23:33:11 +0900
Subject: [PATCH] Make public

---
 .travis.yml     |  3 +++
 License         | 21 +++++++++++++++
 README.md       | 72 +++++++++++++++++++++++++++++++++++++++++++++++++
 multierr.go     | 25 +++++++++++++++++
 mutierr_test.go | 23 ++++++++++++++++
 5 files changed, 144 insertions(+)
 create mode 100644 .travis.yml
 create mode 100644 License
 create mode 100644 README.md
 create mode 100644 multierr.go
 create mode 100644 mutierr_test.go

diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..8b3da87
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,3 @@
+language: go
+go:
+  - "1.10"
diff --git a/License b/License
new file mode 100644
index 0000000..dca5250
--- /dev/null
+++ b/License
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2018 getogrand
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..94eb885
--- /dev/null
+++ b/README.md
@@ -0,0 +1,72 @@
+# multierr
+
+[![GoDoc](https://godoc.org/github.com/getogrand/multierr?status.svg)](https://godoc.org/github.com/getogrand/multierr)
+[![Build Status](https://travis-ci.org/getogrand/multierr.svg?branch=master)](https://travis-ci.org/getogrand/multierr)
+
+Package multierr introduce a simple way to join multiple errors as an error.
+
+## Installation
+
+Run `go get github.com/getogrand/multierr`.
+
+## Usage
+
+The `multierr.Join()` combine multiple errors to an error.
+
+You can report multiple errors as an joined error to the caller using `multierr.Join()`.
+
+```go
+import "github.com/getogrand/multierr"
+
+var ee []error
+
+up := ReservationUserPush{}
+n := ReservationAlarmNoti{}
+
+if err := up.Send(); err != nil {
+  ee = append(ee,
+    fmt.Errorf("send reservation %v push to user: %v", n.Reservation.ID, err))
+}
+
+if err := n.sendShopAlarm(); err != nil {
+  ee = append(ee, fmt.Errorf(
+    "send shop alarm message of reservation %v: %v", n.Reservation.ID, err))
+}
+
+if err := n.sendUserAlarm(); err != nil {
+  ee = append(ee, fmt.Errorf(
+    "send user alarm message of reservation %v: %v", n.Reservation.ID, err))
+}
+
+return multierr.Join(ee) // error{"3 errors occured: send reservation 1 push to user: connection fail, send shop alarm message of reservation 1: connection fail, send user alarm message of reservation 1: connection fail"}
+```
+
+It is really useful when you run errorable operation in for-loop.
+
+```go
+import "github.com/getogrand/multierr"
+
+func SliceConvAtoi32(aa []string) ([]int32, error) {
+	errs := []error{}
+	ii := []int32{}
+	for _, a := range aa {
+		i, err := strconv.Atoi(a)
+		if err != nil {
+			errs = append(errs, fmt.Errorf("convert %q to int: %v", a, err))
+			continue
+		}
+		ii = append(ii, int32(i))
+	}
+
+	if len(errs) > 0 {
+		return []int32{}, multierr.Join(errs)
+	}
+	return ii, nil
+}
+```
+
+## Extracted From [heybeauty](https://heybeauty.me)
+
+## License
+
+Released under the [MIT License](https://github.com/getogrand/multierr/blob/master/License)
diff --git a/multierr.go b/multierr.go
new file mode 100644
index 0000000..62bf876
--- /dev/null
+++ b/multierr.go
@@ -0,0 +1,25 @@
+// Package multierr introduce a simple way to join multiple errors as an error.
+package multierr
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Join combine multiple errors to an error.
+//
+// Error that joined have error string follow below format.
+//
+// `2 errors occured: open file abc.png, close connection of db 'test_db'`
+func Join(errs []error) error {
+	if len(errs) == 0 {
+		return nil
+	}
+
+	var msgs []string
+	for _, e := range errs {
+		msgs = append(msgs, e.Error())
+	}
+	joinedmsg := strings.Join(msgs, ", ")
+	return fmt.Errorf("%d errors occured: %s", len(errs), joinedmsg)
+}
diff --git a/mutierr_test.go b/mutierr_test.go
new file mode 100644
index 0000000..2690816
--- /dev/null
+++ b/mutierr_test.go
@@ -0,0 +1,23 @@
+package multierr_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/getogrand/multierr"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestJoin(t *testing.T) {
+	errors := []error{
+		fmt.Errorf("this is error 1"),
+		fmt.Errorf("this is error 2"),
+		fmt.Errorf("this is error 3"),
+	}
+
+	joinderr := multierr.Join(errors)
+	assert.Error(t, joinderr)
+	assert.Equal(t,
+		"3 errors occured: this is error 1, this is error 2, this is error 3",
+		joinderr.Error())
+}