Biome Enforcement

This skill governs how agents should work with Biome as a repository enforcement tool.

It still preserves the core rule from the prior skill:

• Biome is primarily a final remediation and enforcement pass
• the required final command remains fixed
• the remediation loop remains mandatory
• post-Biome build and test re-validation still occurs only when Biome changed files

This skill is broader than a single final step. Agents should also use it when they need to:

• reason about whether a task is Biome-relevant
• interpret Biome JSON diagnostics
• decide whether generated output belongs in ignore rules
• update Biome configuration safely
• distinguish source issues from tool-noise issues before the final pass

Operational details for how Biome works are defined in:

references/biome.md

Agents must consult that reference when executing this skill.

Concern Ownership

This skill owns Biome-specific execution policy.

It takes precedence whenever the task involves:

• Biome command selection
• Biome diagnostic interpretation
• Biome remediation sequencing
• Biome ignore-path decisions
• post-Biome validation rules

Repository-wide standards skills may still govern adjacent concerns, but they should defer to this skill for Biome behavior.

When This Skill Must Be Used

Activate this skill whenever a task:

• modifies source code
• modifies tests
• adds or removes files in Biome-managed areas
• changes biome.json, related workspace config, or scripts that affect Biome usage
• creates new directories or generated output that may need ignore handling
• requires interpretation of Biome diagnostics or JSON reporter output
• completes an implementation that must be validated before handoff

In practice, this means most coding tasks that touch Biome-managed files should consult this skill, even if Biome itself is only executed at the end.

Execution Timing

Biome must run as the final enforcement routine after implementation and normal validation are already complete.

Agents may consult this skill earlier for planning, config awareness, or ignore-path triage, but they should not turn Biome into a continuous edit-loop tool.

Correct order:

1. Complete implementation
2. Run repository-native validation before Biome such as build, typecheck, and tests
3. Run the Biome remediation loop
4. If Biome modified files:

- re-run the same build and test validation that was already used

1. Declare the task complete

Required Final Command

Always run Biome using the following command:

biome check --write --unsafe --changed --no-errors-on-unmatched --files-ignore-unknown=true --reporter=json

Requirements:

• JSON reporter must always be used
• the command must run against changed files
• autofix must be enabled
• this exact invocation remains the required final enforcement command

Do not substitute alternative reporters or command structures.

Broader Biome Responsibilities

This skill is not limited to "run one command at the end."

Agents should also apply it when working with:

• Biome config updates
• Biome ignore rules
• parser or config failures surfaced by Biome
• lint-rule remediation strategy
• repository changes that expand or shrink the set of files Biome should own

These activities support the final enforcement pass. They do not replace it.

Remediation Loop

If Biome reports errors:

1. Parse the JSON output
2. Convert diagnostics into a remediation task list
3. Resolve the issues
4. Run the Biome command again

Repeat until Biome reports zero errors.

Full remediation workflow details are defined in:

references/biome.md

Ignore Path Responsibilities

If the task introduces generated artifacts or machine-produced output, the agent must determine whether those paths should be ignored by Biome.

Examples may include:

• test artifacts
• playwright output
• coverage reports
• generated snapshots
• build output
• tool-generated directories

Guidance for determining when ignore paths are appropriate is defined in:

references/biome.md

Agents must not add ignore rules for real source code issues.

Final Validation Requirement

Work is not complete until all of the following are true:

• Biome reports zero errors from the required command
• if Biome made changes, the repository-native build and test commands used earlier succeed again
• no new Biome noise remains in the changed scope
• any newly introduced generated output is either ignored appropriately or intentionally Biome-managed

Agent Responsibility

Agents must treat Biome as a mandatory repository enforcement mechanism.

For any coding task:

• consult this skill when Biome-related decisions are required
• run the required Biome command before completion
• use the JSON reporter
• follow the remediation loop
• re-run build and test validation only if Biome modifies files

Agents should consult the reference document for operational details when executing this skill.