Agent-Skills.md

Agent Skills: Rsdoctor Analysis Assistant Skill

Use when analyzing Rspack/Webpack bundles from local `rsdoctor-data.json` and producing evidence-based optimization recommendations.

UncategorizedID: rstackjs/agent-skills/rsdoctor-analysis

Repository

rstackjs/agent-skills
rstackjsLicense: MIT
50

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pnpm dlx add-skill https://github.com/rstackjs/agent-skills/tree/HEAD/skills/rsdoctor-analysis

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skills/rsdoctor-analysis/SKILL.md

Skill Metadata

Name
rsdoctor-analysis
Description
Use when analyzing Rspack/Webpack bundles from local `rsdoctor-data.json` and producing evidence-based optimization recommendations.

Rsdoctor Analysis Assistant Skill

Use the globally installed rsdoctor-agent CLI from @rsdoctor/agent-cli only after a real rsdoctor-data.json path exists. Keep analysis read-only unless the user explicitly asks for install/config setup.

Response order (required): High-Priority Issues -> Proposed Solutions -> Optional Reference-Chain Follow-up Choices -> Next Deep-Dive Issue Categories (Not commands).

Core Workflow

  1. Reuse current-session results and valid .rsdoctor-analysis-cache.json entries before doing new work.
  2. Locate rsdoctor-data.json fast: user-provided path, then dist/rsdoctor-data.json, output/rsdoctor-data.json, static/rsdoctor-data.json, .rsdoctor/rsdoctor-data.json, then one bounded rg --files search excluding node_modules and .git. Treat manifest.json only as an index.
  3. If data exists, skip all plugin version/config/build generation logic. Update cache when useful.
  4. If data is missing, stop analysis: do not run rsdoctor-agent analysis commands, do not run the Analysis Gate, and either ask for the data path or run the Generation Gate below only when setup/generation is required.
  5. After a real data file exists, run Analysis Gate at most once before the first rsdoctor-agent data-fetch command: verify global @rsdoctor/agent-cli with npm view @rsdoctor/agent-cli version and rsdoctor-agent --version; install latest only if missing/outdated, a version-related error occurs, or the user asks to refresh.
  6. Fetch only the Default Evidence Set first; run independent fetches in parallel when possible.
  7. Run the ROI Triage Gate below before selecting deep-dive commands or recommendations. Use it to rank issue categories by measured impact, then synthesize findings in the required response order.

Performance rules: parallelize independent checks, cache only derived facts (dataFile, dataFileMtime, pluginName, pluginVersion, dependency/config/plugin modification times), and invalidate cache when paths disappear, modification times change, the user asks to refresh, or cached values fail. Speculative plugin checks must not trigger generation; use them only after confirming the data file is missing.

ROI Triage Gate

Before recommending fixes, classify the current build into broad cost buckets and choose the highest-ROI lever from evidence, not intuition. This gate is generic for Rspack/Webpack projects; do not use framework-specific runtime layers unless the user's project exposes them in the data.

| Cost bucket | Evidence source | First lever | | -------------------------- | ----------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------- | | Assets/media | assetsTop, assets media, chunkGraph.assets | Compress, convert, deduplicate, subset, or lazy-load large assets | | Large packages/modules | packagesTop, module/package size fields | Replace heavy packages, use deep imports, split non-critical code, or review direct dependency choices | | Duplicate/cross-chunk cost | E1001/E1002, packages duplicates, cross-chunk package summaries | Deduplicate versions, tune package resolution, or adjust splitChunks/cache groups | | Tree-shaking waste | retainedModulesTop, retained CJS/barrel/side-effects modules | Fix CJS/barrel imports, sideEffects declarations, or package entrypoints | | Build-time cost | buildCost, loaders/plugins/directories cost data | Optimize loaders/plugins, cache, watcher, or source-map/dev settings; prioritize only when the user asks about build performance |

Decision rules:

  • Report the measured breakdown first when it changes recommendation priority.
  • Start with the largest bucket that maps to a practical fix; a smaller issue should not outrank a larger one unless the larger one is expected or intentionally unavoidable.
  • Treat issuer/reference-chain tracing as second-pass work. Run it only when a high-impact candidate needs ownership evidence, or when the user asks "why" / "who imported this".
  • Do not present aggregate rule output as sufficient evidence for a fix that requires a concrete file, package, chunk, size, or dependency path.
  • If the largest bucket is structural or intentionally required, say that it is a wall and name the external change that would be needed instead of inventing low-impact source edits.

Generation Gate

Identify pluginName (@rsdoctor/rspack-plugin or @rsdoctor/webpack-plugin) and determine pluginVersion from local files first: package.json, lockfile, then node_modules/<plugin>/package.json; use pnpm why / npm ls only as fallback.

Use this exact if/else decision tree; do not merge branches:

if pluginName is missing:
  install/register the matching Rsdoctor plugin, then configure output.mode='brief' and output.options.type=['json']; build with RSDOCTOR=true only
else if pluginVersion is unknown:
  resolve pluginVersion first; if still unknown, configure output.mode='brief' and output.options.type=['json']; build with RSDOCTOR=true only
else if pluginVersion >= 1.5.11:
  do not edit plugin config just for JSON; build with RSDOCTOR_OUTPUT=json and RSDOCTOR=true if needed
else: # pluginVersion < 1.5.11
  MUST configure output.mode='brief' and output.options.type=['json']; build with RSDOCTOR=true only

Preflight every build command: RSDOCTOR_OUTPUT=json is allowed only in the pluginVersion >= 1.5.11 branch. For missing, unknown, or < 1.5.11, it is forbidden. For < 1.5.11, generating rsdoctor-data.json requires the plugin config below:

output: {
  mode: 'brief',
  options: {
    type: ['json'],
  },
}

Evidence and Command Bounds

Default Evidence Set:

| Summary key | Evidence source | Bounds | | -------------------- | ------------------------------------------ | --------------------------------------------- | | buildCost | build summary | filtered fields only | | assetsTop | top assets by raw/gzip size | fixed Top-N | | packagesTop | top packages by gzip size | fixed Top-N; avoid full packages list pages | | duplicatePackages | E1001 duplicate package summary | first-pass summary only | | crossChunkPackages | E1002 cross-chunk duplication summary | first-pass summary only | | retainedModulesTop | tree-shaking retained-modules --limit 10 | filtered fields only; no --compact |

Scope rules:

  • Use rsdoctor-agent for bundle data access only after rsdoctor-data.json exists; prefer parallel independent fetches; bound output with --filter, pagination, and --limit.
  • Default analysis stays within the Default Evidence Set. For non-default analysis, choose minimal fields from references/rsdoctor-data-types.md and patterns from references/common-analysis-patterns.md.
  • Treat chain tracing, broad commands, optimization edits, splitChunks experiments, and build re-runs as opt-in follow-ups that require user confirmation.
  • For duplicate packages and tree-shaking issues, identify issues first; trace reference/import chains only after user confirmation.
  • Prefer tree-shaking retained-modules --emitted-only --category side-effects --limit 10 with narrow --filter for side-effects investigations.
  • For retained emitted modules, use tree-shaking retained-modules with --emitted-only, bounded --category, --sort gzipSize, --limit, and narrow --filter; do not pass --compact.
  • Use tree-shaking summary only as fallback for missing fields or aggregate context. Treat tree-shaking bailout-reasons as high-volume; run it only when explicitly requested and pass target --modules (max 100).
  • If any command exceeds 5k tokens, 500 KB raw output, or a few hundred transcript lines, stop broad fetching and switch to targeted compact queries.

Output and Recovery

Output format:

  1. Issues found in the current build and recommended fixes:
    • Group each issue with its fix recommendation.
    • Include concrete evidence (size/time/count/path/rule code) and priority.
    • For duplicate packages and tree-shaking issues, include a short "continue tracing vs stop here" choice.
  2. Whether deeper analysis is still needed:
    • List remaining issue categories only, not commands.

For Top-N insights, prefer a table: Name | Volume/Time | Count | Recommendation.

Recovery rules:

  • rsdoctor-data.json missing: do not run rsdoctor-agent; ask for the data path or run Generation Gate, then use the matching install reference if setup is needed.
  • Command not found: run Analysis Gate, then retry with rsdoctor-agent.
  • query reports unknown tool: run list and use a catalog tool name, or switch to direct <group> <subcommand> mode.
  • JSON read error: verify file path, JSON validity, and permissions.
  • Run installs, builds, version checks, and rsdoctor-agent... commands only in the host's authorized command environment when it has the required project, dependency, and network access. If the available environment lacks that access, stop and ask the user instead of attempting to bypass the sandbox or permission boundary. Clearly identify the missing permission or access; if an Rsdoctor dependency must be installed, tell the user which dependency is required and provide the appropriate package-manager command for them to run.

References: commands/options references/command-map.md; install/config/data location references/install-rsdoctor.md, references/install-rsdoctor-rspack.md, references/install-rsdoctor-webpack.md, references/install-rsdoctor-common.md; raw data fields references/rsdoctor-data-types.md; common patterns references/common-analysis-patterns.md.