.prettierignore — managed block (E3)

Status: shipped-beta · Ships to: npm-lane, all tier arms (core / env+ / factory), every npm stack · Fires at: install time and every --refresh (both call merge_prettierignore on the project root's .prettierignore)

What it is

The shared template .prettierignore — the pattern set that keeps prettier off files the framework generates or ships: the rendered RULES.md table region, the framework-authored .ai-factory/ docs, install-generated configs (.claude/settings.json, .mcp.json, the eslint barrel), vendored framework source (packages/core/hooks/**, eslint-rules-local/, .claude/vendor/runtime-bridge/**) and lockfiles. The "managed block" is the delivery mechanism: on a consumer who already has a .prettierignore, missing patterns are merged inside # >>> rules-as-tests-aif (managed) >>> / <<< fence markers rather than the file being overwritten.

How it works

• Greenfield (no .prettierignore on disk): the merge helper defers entirely to copy_safe, so the delivered file is byte-identical to the template.
• Brownfield: merge_prettierignore collects every shipped pattern not already present verbatim in the consumer file and inserts the missing ones immediately before the managed END marker — the block stays single (GH #890: marker presence no longer short-circuits delivery, so a NEW shipped pattern reaches already-installed consumers on repeat --full or --refresh).
• If the consumer already has every shipped pattern, the merge is a genuine idempotent no-op.
• A sibling .prettierignore.override.md marks the file consumer-owned: install and refresh skip it entirely (the refresh arm checks for it before calling the merge).
• --force collapses the merge to a wholesale copy_safe overwrite.
• Lane honesty: the python, cargo and go lanes never deliver .prettierignore — none of setup.d/45/46/47 calls merge_prettierignore.

Satellites & companions

USES copy_safe (A3) for the greenfield path and the fence constants PRETTIERIGNORE_BEGIN/END from setup.d/lib.sh. Companions: the config files it protects — the rendered RULES.md (E5 family), integration-rules.md (E14), tsconfig.json (E19, conditionally via ignore_shipped_configs), and the vendor drop of 55-runtime-bridge-vendor.sh. ADDS over a plain ignore file: per-pattern merge, so consumer-owned ignores outside the managed block survive every install.

Anchors

At framework pin aa87d0a47a6d8502f983cc9fe7284bd5dcb3d650:

• packages/core/templates/shared/.prettierignore:1 — «# Generated rule docs — the <!-- begin/end: rules-table-generated --> region is rendered»
• packages/core/templates/shared/.prettierignore:6 — «.ai-factory/RULES.md»
• packages/core/templates/shared/.prettierignore:28 — «.ai-factory/rules/integration-rules.md»
• setup.d/lib.sh:65 — «PRETTIERIGNORE_BEGIN='# >>> rules-as-tests-aif (managed) >>>'»
• setup.d/40-configs.sh:132 — «merge_prettierignore "$PKG_ROOT/packages/core/templates/shared/.prettierignore" "$PROJECT_ROOT/.prettierignore"»
• install.sh:1321 — «merge_prettierignore "$PKG_ROOT/packages/core/templates/shared/.prettierignore" "$PROJECT_ROOT/.prettierignore"»
• setup.d/lib.sh:1385-1387 — «# No consumer file → greenfield: copy byte-identical (defer entirely to copy_safe).» … «copy_safe "$src" "$dst"»