Config

Finds the linter config, checks it, and works out the paths the run uses. It runs first, before any form is read.

The linter looks for sdc-questionnaire-lint.config.json or sdc-questionnaire-lint.config.mjs in the working directory only, not in its parents. --config names a file explicitly and never falls back to that search. Running without a config is fine: the defaults below apply. A .mjs config is imported, so it runs its own code and the code of the plugins it imports. Only an .mjs config can list plugins.

Every key is checked, and an unknown key is an error, so a mistyped setting is never silently ignored. A missing, unreadable or invalid config stops the run with CONFIG_INVALID, which exits with code 2. Paths in the config are relative to the config's directory.

Key	What it sets	Default
files	The compiled files or globs to lint	fsh-generated/resources
source.fsh	The FSH directories used to trace findings to source	input/fsh
hostVariables	Names the application running the form supplies, written without %. A name FHIRPath, FHIR or SDC defines is an error.	none
plugins	Plugins to load, in an .mjs config only	none
compat	The runtime versions each plugin checks against	latest
rules	A severity, or off, for each rule	each rule's own severity
suppress	Findings to hide, each with a reason	none

Configuration shows example configs, and Configuration and path bases is the full contract.

Schema

Without a config, loadConfig returns null, and resolveRunPaths resolves the defaults against the working directory.

Code

In packages/core/src/config/:

• load.ts: loadConfig finds, reads and validates the config. It returns a LoadedConfig with the file's path, its directory, the path to show in messages, the format and the config, or null when there is none.
• validate.ts: validateConfig checks every key and every suppression entry. An error names the config file and the JSON Pointer of the bad entry. Rule IDs and plugins are checked later, by Plugins and rule set, which knows them.
• types.ts: the LintConfig type, and defineConfig, which types the default export of an .mjs config.
• paths.ts: resolveRunPaths makes the absolute paths the run uses, from the config or the defaults: the input files, the FSH directories and SUSHI's index file.