From 1bebeb5aa592da6bda97386d912c1e9f13943034 Mon Sep 17 00:00:00 2001
From: Nathan Leiby <nathan.leiby@clever.com>
Date: Tue, 15 Aug 2017 11:46:59 -0700
Subject: [PATCH] decode: json decodes dimensions as array of interface

Previously, this would result in a log line failing to extracting any
dimensions because

```golang
dimensions.([]string)
```

would fail because

```golang
reflect.TypeOf(dimensions)
```

was `[]interface{}`.
---
 decode/decode.go      | 11 ++++++++++-
 decode/decode_test.go | 12 ++++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/decode/decode.go b/decode/decode.go
index 47f08cc..dd8666d 100644
--- a/decode/decode.go
+++ b/decode/decode.go
@@ -154,11 +154,20 @@ func getStringArray(json map[string]interface{}, key string) []string {
 		return []string{}
 	}
 
-	strArray, ok := val.([]string)
+	iArray, ok := val.([]interface{})
 	if !ok {
 		return []string{}
 	}
 
+	strArray := []string{}
+	for _, item := range iArray {
+		s, ok := item.(string)
+		if !ok {
+			return []string{}
+		}
+		strArray = append(strArray, s)
+	}
+
 	return strArray
 }
 
diff --git a/decode/decode_test.go b/decode/decode_test.go
index 22877a5..59e9b11 100644
--- a/decode/decode_test.go
+++ b/decode/decode_test.go
@@ -562,13 +562,13 @@ func TestExtractKVMeta(t *testing.T) {
 							"rule":        "cool",
 							"series":      "1,1,2,3,5,8,13",
 							"value_field": "value",
-							"dimensions":  []string{"app", "district"},
+							"dimensions":  []interface{}{"app", "district"},
 						},
 						map[string]interface{}{
 							"type":       "metrics",
 							"rule":       "cool2",
 							"series":     "1,1,2,6,24,120,720,5040",
-							"dimensions": []string{"app", "district"},
+							"dimensions": []interface{}{"app", "district"},
 						},
 					},
 				},
@@ -688,7 +688,7 @@ func TestExtractKVMeta(t *testing.T) {
 							"type":        "alerts",
 							"rule":        "last-call",
 							"series":      "doing-it-til-we-fall",
-							"dimensions":  []string{"who", "where"},
+							"dimensions":  []interface{}{"who", "where"},
 							"stat_type":   "guage",
 							"value_field": "status",
 						},
@@ -696,7 +696,7 @@ func TestExtractKVMeta(t *testing.T) {
 							"type":       "alerts",
 							"rule":       "watch-out-now",
 							"series":     "dem-gators-gonna-bite-ya",
-							"dimensions": []string{"how-fresh", "how-clean"},
+							"dimensions": []interface{}{"how-fresh", "how-clean"},
 						},
 					},
 				},
@@ -750,7 +750,7 @@ func TestExtractKVMeta(t *testing.T) {
 							"type":       "metrics",
 							"rule":       "all-combos",
 							"series":     "1,1,2,6,24,120,720,5040",
-							"dimensions": []string{"fact", "orial"},
+							"dimensions": []interface{}{"fact", "orial"},
 						},
 						map[string]interface{}{
 							"type":   "analytics",
@@ -767,7 +767,7 @@ func TestExtractKVMeta(t *testing.T) {
 							"type":        "alerts",
 							"rule":        "last-call",
 							"series":      "doing-it-til-we-fall",
-							"dimensions":  []string{"who", "where"},
+							"dimensions":  []interface{}{"who", "where"},
 							"stat_type":   "guage",
 							"value_field": "status",
 						},