From 5018c7415a24eff52005be83fd254dd9c6391991 Mon Sep 17 00:00:00 2001
From: Jason Mooberry <jason.mooberry@gmail.com>
Date: Tue, 23 May 2017 18:12:17 -0400
Subject: [PATCH] Allow comments in mapping files

---
 README.md      | 1 +
 mapper.go      | 5 +++++
 mapper_test.go | 5 ++++-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 710bc73..65322f4 100644
--- a/README.md
+++ b/README.md
@@ -88,6 +88,7 @@ with `-statsd.add-suffix=false`.
 
 An example mapping configuration with `-statsd.add-suffix=false`:
 
+    # comments are allowed
     test.dispatcher.*.*.*
     name="dispatcher_events_total"
     processor="$1"
diff --git a/mapper.go b/mapper.go
index b05349d..f6efc24 100644
--- a/mapper.go
+++ b/mapper.go
@@ -59,6 +59,11 @@ func (m *metricMapper) initFromString(fileContents string) error {
 	for i, line := range lines {
 		line := strings.TrimSpace(line)
 
+		// skip comments
+		if strings.HasPrefix(line, "#") {
+			continue
+		}
+
 		switch state {
 		case SEARCHING:
 			if line == "" {
diff --git a/mapper_test.go b/mapper_test.go
index 217e70a..61ef835 100644
--- a/mapper_test.go
+++ b/mapper_test.go
@@ -28,11 +28,14 @@ func TestMetricMapper(t *testing.T) {
 		// Config with several mapping definitions.
 		{
 			config: `
+				# this is a comment
+				# this is another
 				test.dispatcher.*.*.*
 				name="dispatch_events"
 				processor="$1"
 				action="$2"
 				result="$3"
+				# here is a third
 				job="test_dispatcher"
 
 				test.my-dispatch-host01.name.dispatcher.*.*.*
@@ -148,7 +151,7 @@ func TestMetricMapper(t *testing.T) {
 				test.bar
 				name="name_bar"
 				label="foo"
-				
+
 				test.foo
 				name="name_foo"
 				label="bar"`,