Make sure that the backslash+n char sequences are converted to the `\…

…n` newline escape char in the message texts (#17)

* Make sure that the backslash+n char sequences are converted to the `\n` newline escape char in the message texts

Related discussion: https://discuss.bitrise.io/t/slack-step-does-not-treat-n-as-a-newline-when-message-generated-by-a-bash-script-step/1776

* go deps update

bitrise.yml

@@ -9,6 +9,7 @@ workflows:
   do-vendor-update:
     steps:
     - script:
+        title: go deps update
         inputs:
         - content: |
             #!/bin/bash
@@ -17,6 +18,8 @@ workflows:
             rm -rf ./Godeps
             rm -rf ./vendor
             go get -t -d ./...
+            go get github.com/davecgh/go-spew/spew
+            go get github.com/pmezard/go-difflib/difflib
             godep save ./...
   fail-message-test:
     steps:
@@ -85,6 +88,13 @@ workflows:
             bitrise share finish
   test:
     steps:
+    - script:
+        title: go test
+        inputs:
+        - content: |
+            #!/bin/bash
+            set -ex
+            go test ./...
     - path::./:
         title: On Success
         is_skippable: false
@@ -134,3 +144,20 @@ workflows:
             and _some_ *highlight*
         - color: good
         - image_url: https://media.giphy.com/media/6brH8dM3zeMyA/giphy.gif
+    - [email protected]:
+        title: Generate SLACK_MESSAGE_FROM_SCRIPT
+        inputs:
+        - content: |-
+            #!/bin/bash
+            set -ex
+
+            multi_line_msg="Multi\nline\n\ntext"
+            envman add --key SLACK_MESSAGE_FROM_SCRIPT --value "$multi_line_msg"
+    - path::./:
+        title: Should escape backslash+n as newline char
+        is_skippable: false
+        inputs:
+        - webhook_url: $SLACK_WEBHOOK_URL
+        - channel: $SLACK_CHANNEL
+        - from_username: step-dev-test
+        - message: $SLACK_MESSAGE_FROM_SCRIPT

main.go

@@ -9,6 +9,8 @@ import (
 	"net/url"
 	"os"
 
+	"strings"
+
 	"github.com/bitrise-io/go-utils/colorstring"
 )
 
@@ -85,13 +87,13 @@ func (configs ConfigsModel) print() {
 func (configs ConfigsModel) validate() error {
 	// required
 	if configs.WebhookURL == "" {
-		return errors.New("No Webhook URL parameter specified!")
+		return errors.New("No Webhook URL parameter specified")
 	}
 	if configs.Message == "" {
-		return errors.New("No Message parameter specified!")
+		return errors.New("No Message parameter specified")
 	}
 	if configs.Color == "" {
-		return errors.New("No Color parameter specified!")
+		return errors.New("No Color parameter specified")
 	}
 
 	return nil
@@ -119,6 +121,11 @@ type RequestParams struct {
 	IconURL   *string `json:"icon_url"`
 }
 
+// ensureNewlineEscapeChar replaces the "\" + "n" char sequences with the "\n" newline char
+func ensureNewlineEscapeChar(s string) string {
+	return strings.Replace(s, "\\"+"n", "\n", -1)
+}
+
 // CreatePayloadParam ...
 func CreatePayloadParam(configs ConfigsModel) (string, error) {
 	// - required
@@ -138,6 +145,7 @@ func CreatePayloadParam(configs ConfigsModel) (string, error) {
 			msgText = configs.MessageOnError
 		}
 	}
+	msgText = ensureNewlineEscapeChar(msgText)
 	// - optional attachment params
 	msgImage := configs.ImageURL
 	if configs.IsBuildFailed {

main_test.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ensureNewlineEscapeChar(t *testing.T) {
+	require.Equal(t, "", ensureNewlineEscapeChar(""))
+	require.Equal(t, "a", ensureNewlineEscapeChar("a"))
+	require.Equal(t, "\n", ensureNewlineEscapeChar("\n"))
+	require.Equal(t, "\n", ensureNewlineEscapeChar("\\"+"n"))
+	// should convert \ + n to \n too; where \n is a single char, the ASCII 10 "newline feed" char
+	require.Equal(t, uint8(10), ensureNewlineEscapeChar("\n")[0])
+	require.Equal(t, uint8(10), ensureNewlineEscapeChar("\\" + "n")[0])
+}