[Project Solar / Phase 1 / Engineering Follow-ups] Improve validation for $modes

[didoo]

📌 Summary

Small PR that adds some basic validation to the design tokens build script, to make sure the $modes entry have the expected format and values.

🛠️ Detailed description

In this PR I have:

• added chalk as devDependency (used to highlight some text in the console messages)
• added two validations to the replace-value-for-mode-${mode} preprocessing function:
  • a "soft" validation that logs a warning in the console (but doesn't block the execution) for when the $modes.default value is different from the standard $value
    • this happens a lot, when copy&pasting blocks of JSON code from a token to another
  • a "hard" validation that throws an error and stops the execution when one of the expected $modes keys is missing

Note: later we may decide to make also the first validation a blocker, for now we want to test how this "soft" check works for the developers adding tokens for the migration of the HDS components to Carbon

🔗 External links

Jira ticket: https://hashicorp.atlassian.net/browse/HDS-5668

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👀 Component checklist

💬 Please consider using conventional comments when reviewing this PR.

📋 PCI review checklist

• If applicable, I've documented a plan to revert these changes if they require more than reverting the pull request.
• If applicable, I've worked with GRC to document the impact of any changes to security controls.
  Examples of changes to controls include access controls, encryption, logging, etc.
• If applicable, I've worked with GRC to ensure compliance due to a significant change to the in-scope PCI environment.
  Examples include changes to operating systems, ports, protocols, services, cryptography-related components, PII processing code, etc.

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Project	Deployment	Preview	Updated (UTC)
hds-showcase	Ready	Preview	Dec 5, 2025 10:34am
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[Copilot]

Pull request overview

This PR enhances validation for design token $modes entries in the build script to catch configuration errors early. It adds two levels of validation: a warning for mismatched default mode values and an error that halts execution when expected mode keys are missing.

Key changes:

• Added chalk dependency for improved console output formatting
• Implemented soft validation warning when $modes.default differs from $value
• Converted TODO comment into hard validation that throws an error for missing mode keys

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated no comments.

File	Description
packages/tokens/scripts/build.ts	Added validation logic for $modes with chalk-formatted console messages
packages/tokens/package.json	Added chalk dependency for colored console output

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

[KristinLBradley]

Looks good other than the duplicated warning messages I was seeing when I tested.

[didoo]

Looks good other than the duplicated warning messages I was seeing when I tested.

@KristinLBradley I have now pushed another commit, to improve the log messages. Now you can see that there are two warnings, because it's invoked twice, for two build paths (the CSS files generation and the JSON doc file generation)

[KristinLBradley]

Can approve after failing check passes