Surface invalid theme check config as an error instead of crashing

[PhilippeCollin]

WHY are these changes introduced?

shopify theme check crashes with an unhandled error when its configuration can't be loaded:

Error: ENOENT: no such file or directory, open './.theme-check.yml'

theme check passes the --config value (or a discovered .theme-check.yml) straight into @shopify/theme-check-node's config loader with no error handling, so any config-loading failure escapes as an unexpected crash instead of an actionable message. The same root cause covers a whole class of failures: missing file, inline config string where a path is expected, empty --config, a directory (EISDIR), and malformed YAML. These are configuration problems, not CLI bugs.

What is happening?

A new loadThemeCheckConfig helper wraps loadConfig and turns any config-loading failure into a user-facing AbortError (shown to the user, not reported as a bug). Config loading is a single, well-defined step — the first thing themeCheckRun does, and what --print/--list already call — so a failure there is by definition a config problem; no error-message parsing needed. The fs error code (ENOENT/EISDIR) only refines the message:

• Missing file → The Theme Check configuration file couldn't be found: <path>.
• Directory → The Theme Check configuration path is a directory, not a file: <path>.
• Anything else → The Theme Check configuration is invalid. (with the underlying detail)

…each with a hint to pass a valid .theme-check.yml or a preset like theme-check:recommended. Later phases (globbing, parsing, the checks) aren't caught here, so genuine bugs still report.

How to test your changes?

1. shopify theme check --config ./does-not-exist.yml → clear "couldn't be found" message (was a crash).
2. shopify theme check --config <a directory> → clear "not a file" message.
3. A .theme-check.yml with an invalid shape → clear "configuration is invalid" message.

Tests

• Unit: describeThemeCheckConfigError (missing file, directory, other failure, non-Error value) and loadThemeCheckConfig (resolves on success; wraps any failure in AbortError).
• Integration: theme check surfaces a missing/malformed config as AbortError, and an error from the check phase still propagates unchanged.

[Copilot]

Pull request overview

This PR prevents shopify theme check from crashing when Theme Check configuration resolution/loading fails, and instead surfaces those failures as user-facing AbortErrors (so they’re treated as expected errors and not reported as unhandled bugs).

Changes:

• Added throwIfThemeCheckConfigError to classify known config-loading failures (missing file/dir path, invalid YAML/config) and rethrow them as AbortErrors.
• Wrapped theme check config-loading operations (--print, --list, and the main run) to apply the new config error handling while rethrowing unrelated errors unchanged.
• Added unit + integration tests covering the new behavior, plus a changeset for a patch release.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/theme/src/cli/services/check.ts	Adds throwIfThemeCheckConfigError and supporting helpers to convert known config-resolution errors into AbortErrors.
packages/theme/src/cli/services/check.test.ts	Adds unit tests for throwIfThemeCheckConfigError and adjusts output mocking to preserve other exports.
packages/theme/src/cli/commands/theme/check.ts	Wraps config-related operations in runWithConfigErrorHandling so config failures surface as AbortErrors instead of unhandled exceptions.
packages/theme/src/cli/commands/theme/check.test.ts	Adds integration tests verifying missing/malformed configs become AbortErrors and unrelated errors still propagate.
.changeset/theme-check-config-errors.md	Declares a patch changeset describing the improved error surfacing for invalid Theme Check configs.

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