UnknownFormatterError

The Cause

You specified a formatter that doesn’t exist. Formatters control how Thymian reports are displayed.

Available formatters:

• markdown - Markdown format (written to a file)
• csv - Comma-separated values (CSV, written to a file)

The CLI also prints a plain-text summary to stdout on every run; that is not a configurable plugin-reporter formatter.

The Solution

Check your configuration file for typos in the formatter name:

thymian.config.yaml

plugins:
  '@thymian/plugin-reporter':
    options:
      formatters:
        markdown: {} # ✅ Valid
        my-custom: {} # ❌ Unknown formatter

If you want to add a custom formatter, you need to create a plugin that listens to the core.report event:

export default function myFormatterPlugin(emitter) {
  emitter.on('core.report', ({ report }) => {
    // Custom formatting logic
  });
}

For more information on creating custom formatters, see the plugin documentation.