Testing

When relying on OpenTelemetry for your Observability needs, it can be important to test that certain spans are created and attributes correctly set. For example, can you be sure that you attaching the right metadata to data that ultimately powers an SLO? This document covers an approach to that kind of validation.

Setup

Only the opentelemetry and opentelemetry_api libraries are required for testing in Elixir/Erlang:

• Erlang
• Elixir

Set your exporter to :none and the span processor to :otel_simple_processor. This ensure that your tests don’t actually export data to a destination, and that spans can be analyzed after they are processed.

• Erlang
• Elixir

A modified version of the hello function from the Getting Started guide will serve as our test case:

• Erlang
• Elixir

Testing

• Erlang
• Elixir