check

Compare generated files against current OpenAPI specifications to detect drift.

Usage

sparktype check [options]

Options

Option	Alias	Description
--config <path>	-c	Path to configuration file

Purpose

The check command verifies that your generated type files match what would be generated from the current OpenAPI specifications. It's designed for CI/CD pipelines to ensure generated types stay in sync.

Key behaviors:

• Does not modify any files
• Compares existing files against expected output
• Exits with code 1 if any files are out of sync
• Shows detailed diff of what changed

Examples

Basic Check

sparktype check

Output when in sync:

Checking ./src/types/api.ts... OK
Checking ./src/schemas/api.ts... OK

All files are in sync.

Output when out of sync:

Checking ./src/types/api.ts... MISMATCH
  User:
    + email: string (added)
    ~ name: string -> string | undefined
Checking ./src/schemas/api.ts... OK

1 file(s) out of sync. Run 'sparktype generate' to update.

Missing Files

If a generated file doesn't exist:

Checking ./src/types/api.ts... MISSING

1 file(s) out of sync. Run 'sparktype generate' to update.

Custom Config Path

sparktype check --config ./config/typegen.jsonc

Exit Codes

Code	Meaning
0	All files are in sync
1	One or more files are out of sync or missing

Diff Output

When files differ, check shows a structured diff:

Checking ./src/types/api.ts... MISMATCH
  + NewType (added)
  - RemovedType (removed)
  ChangedType:
    + newField: string (added)
    - oldField: number (removed)
    ~ modifiedField: string -> number

Diff Symbols

Symbol	Meaning
+	Added (type or property)
-	Removed (type or property)
~	Changed (shows old → new value)

Workflow Recommendations

Fail Early

Run check early in your CI pipeline, before tests or builds:

jobs:
  lint:
    # ...
  
  check-types:
    # ...
  
  test:
    needs: [lint, check-types]
    # ...

Require Regeneration

When check fails, developers should:

1. Run sparktype generate locally
2. Review the changes
3. Commit the updated files

Don't Auto-Generate in CI

Avoid running generate in CI and committing automatically. This hides spec changes from code review.

Instead:

1. Run check in CI (fails if out of sync)
2. Require developers to run generate locally
3. Include generated files in code review

Comparison vs Generation

Aspect	generate	check
Modifies files	Yes	No
Exit code on diff	N/A	1
Shows diff	No	Yes
Use case	Development	CI/CD

Troubleshooting

False Positives

If check reports differences but generate produces the same file:

1. Ensure you're using the same sparktype version in CI and locally
2. Check for line ending differences (CRLF vs LF)
3. Verify the same config options are used

Performance

For large specs, check may take a few seconds. Cache dependencies in CI:

- uses: actions/cache@v4
  with:
    path: ~/.npm
    key: ${{ runner.os }}-npm-${{ hashFiles('**/package-lock.json') }}

See Also

• generate command
• CI/CD Integration Guide
• Configuration