From 9656297762bb988868146b1e93cd4c7e6625e8cf Mon Sep 17 00:00:00 2001
From: Holger Just <hello@holgerjust.de>
Date: Sat, 22 Jul 2017 00:06:35 +0200
Subject: [PATCH] Remove ANSI color codes from the message in JSON encoder

---
 lib/rackstash/encoders/json.rb       | 8 ++++++--
 spec/rackstash/encoders/json_spec.rb | 5 +++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/rackstash/encoders/json.rb b/lib/rackstash/encoders/json.rb
index b6442c2..33be4ed 100644
--- a/lib/rackstash/encoders/json.rb
+++ b/lib/rackstash/encoders/json.rb
@@ -11,7 +11,8 @@ module Rackstash
   module Encoders
     # The JSON encoder formats the log event as a single-line JSON string. The
     # resulting JSON string contains all data exposed by the buffer. Leading
-    # and trailing whitespace on the `"message"` field will be removed.
+    # and trailing whitespace as well as any ANSI color codes in the `"message"`
+    # field will be removed.
     #
     # The resulting string is in the JSON format native to Logstash. You can
     # thus ship your logs directly to Logstash without further processing by
@@ -23,7 +24,10 @@ module Rackstash
       # @param event [Hash] a log event as produced by the {Flow}
       # @return [String] the event as a single-line JSON string
       def encode(event)
-        event[FIELD_MESSAGE] = event[FIELD_MESSAGE].strip
+        event[FIELD_MESSAGE] = event[FIELD_MESSAGE]
+          .gsub(/\e\[[0-9;]*m/, EMPTY_STRING)
+          .strip
+
         ::JSON.dump(event)
       end
     end
diff --git a/spec/rackstash/encoders/json_spec.rb b/spec/rackstash/encoders/json_spec.rb
index 8779864..5da1a6f 100644
--- a/spec/rackstash/encoders/json_spec.rb
+++ b/spec/rackstash/encoders/json_spec.rb
@@ -27,5 +27,10 @@ describe Rackstash::Encoders::JSON do
       event = { 'message' => "\n\t \nline1\nline2\n  \n\t\n" }
       expect(encoder.encode(event)).to eql '{"message":"line1\nline2"}'
     end
+
+    it 'removes any ANSI color codes from the message' do
+      event = { 'message' => "Important\n\e[31mRED TEXT\e[0m\nOK" }
+      expect(encoder.encode(event)).to eql '{"message":"Important\nRED TEXT\nOK"}'
+    end
   end
 end