From a42da92b1ff16c48eb40dc081d3b4fbd6480c7c0 Mon Sep 17 00:00:00 2001
From: Tom de Bruijn <tom@tomdebruijn.com>
Date: Tue, 29 Aug 2023 15:06:48 +0200
Subject: [PATCH] Log error when sample data is invalid type (#992)

Log an error when a value other than an Array or Hash is given to sample
data to help debug why the sample data is not appearing.

Related Slack conversation:
https://appsignal.slack.com/archives/CNPP953E2/p1693295505307779
---
 .../log-error-when-sample-data-is-invalid-format.md      | 6 ++++++
 lib/appsignal/transaction.rb                             | 9 ++++++++-
 spec/lib/appsignal/transaction_spec.rb                   | 2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 .changesets/log-error-when-sample-data-is-invalid-format.md

diff --git a/.changesets/log-error-when-sample-data-is-invalid-format.md b/.changesets/log-error-when-sample-data-is-invalid-format.md
new file mode 100644
index 000000000..10229cb8a
--- /dev/null
+++ b/.changesets/log-error-when-sample-data-is-invalid-format.md
@@ -0,0 +1,6 @@
+---
+bump: "patch"
+type: "change"
+---
+
+Log an error when sample data is of an invalid type. Accepted types are Array and Hash. If any other types are given, it will log an error to the `appsignal.log` file.
diff --git a/lib/appsignal/transaction.rb b/lib/appsignal/transaction.rb
index 20854b4c3..27f73f315 100644
--- a/lib/appsignal/transaction.rb
+++ b/lib/appsignal/transaction.rb
@@ -320,7 +320,14 @@ def set_metadata(key, value)
     end
 
     def set_sample_data(key, data)
-      return unless key && data && (data.is_a?(Array) || data.is_a?(Hash))
+      return unless key && data
+
+      if !data.is_a?(Array) && !data.is_a?(Hash)
+        Appsignal.logger.error(
+          "Invalid sample data for '#{key}'. Value is not an Array or Hash: '#{data.inspect}'"
+        )
+        return
+      end
 
       @ext.set_sample_data(
         key.to_s,
diff --git a/spec/lib/appsignal/transaction_spec.rb b/spec/lib/appsignal/transaction_spec.rb
index e34a5883d..5c1fef577 100644
--- a/spec/lib/appsignal/transaction_spec.rb
+++ b/spec/lib/appsignal/transaction_spec.rb
@@ -688,6 +688,8 @@ def current_transaction
           transaction.set_sample_data("params", "string")
 
           expect(transaction.to_h["sample_data"]).to eq({})
+          expect(log_contents(log)).to contains_log :error,
+            %(Invalid sample data for 'params'. Value is not an Array or Hash: '"string"')
         end
       end