Add unit tests for parsers

**Description**
Currently controllers lacks proper compression support.

**Proposed solution**
Add configurable compression with sensible defaults.

**Priority**: Low/Medium

The issue refers to parsers and controllers but names no files, tests, or entry points. First locate the controller compression path and existing parser unit tests, then clarify whether the deliverable is tests, configurable compression, or both; done means the intended compression defaults and configuration are covered by passing unit tests.

Written by the indexing model from the issue text.