Purpose-built utilities, schemas, and workflows that power our Liquid {% data %} and {% indented_data_reference %} tags, reusable content, UI strings, and feature metadata. This subject focuses on how we read, validate, and serve files in data/ across languages.

• Provide a consistent API (getDataByLanguage, getDeepDataByLanguage) to load data/ files for Liquid rendering and server contexts.
• Enforce schemas for critical data (features, variables, release notes, tables, glossaries, code languages, CTAs).
• Ship CLI and CI helpers that keep data/ clean (orphaned feature detection, deleted-feature PR guardrails).
• Exclude: content authoring guidance (see content/), page routing (see src/app/src/frame), and general linter rules (see src/content-linter).

• lib/get-data.ts: translation-aware loader with memoized reads, forced-English exceptions, and UI data merging; used by Liquid tags and server contexts.
• lib/data-directory.ts + lib/filename-to-key.ts: generic walker that turns files into dotted-key objects with optional preprocessing.
• lib/data-schemas/: AJV schema registry that auto-discovers data/tables/*.yml schemas and registers other critical shapes (features, variables, release notes, glossaries, code languages, CTAs).
• Middleware: middleware/data-tables.ts caches table data into req.context.tables (English).
• Scripts: scripts/find-orphaned-features/* (detect/delete unused data/features/*.yml) and scripts/deleted-features-pr-comment.ts (warn on feature deletions in PRs).
• Tests: tests/ cover schema validation, data loading, key normalization, and orphan detection fixtures.

• lib/get-data.ts
  • getDataByLanguage(dottedPath, langCode): Returns a single value (YAML/MD/variables/reusables/ui/glossaries/release-notes).
  • getDeepDataByLanguage(dottedPath, langCode): Returns nested objects for an entire subtree (e.g., tables, features).
  • Translation fallbacks: If a localized file is missing or unparsable, falls back to English. Certain files are forced-English (ALWAYS_ENGLISH_YAML_FILES, ALWAYS_ENGLISH_MD_FILES).
  • Memoization: Caches reads except in NODE_ENV=development to simplify local debugging.
• lib/data-directory.ts
  • Recursively walks a directory, filters by extensions (.json, .md/.markdown, .yml) and ignore patterns, and emits a dotted-key object using filename-to-key.
  • Optional preprocess hook for content transformation (used in tests/prior scripts).

• Schema registry: lib/data-schemas/index.ts maps data paths to schema modules; auto-registers any data/tables/*.yml that has a matching data-schemas/tables/{name}.ts.
• Tests: src/data-directory/tests/data-schemas.ts loads schemas via AJV and asserts every registered file validates.
• Adding a schema:
  1. Create src/data-directory/lib/data-schemas/<name>.ts (or tables/<table>.ts).
  2. If non-table, add to manualSchemas in data-schemas/index.ts; table schemas are auto-detected.
  3. Run tests (see below).

• middleware/data-tables.ts populates req.context.tables with getDeepDataByLanguage('tables', 'en'). Intended for server/Express contexts where table data is needed without per-request file IO.

• npm run find-orphaned-features -- --source-directory data/features --output orphans.json
  • Scans pages, reusables, variables (all languages) for {% ifversion %} feature references and reports unused data/features/*.yml.
• npm run find-orphaned-features delete -- orphans.json --max 10
  • Deletes up to N orphaned feature files (English root) after manual review.
• npm run deleted-features-pr-comment -- <owner> <repo> <base_sha> <head_sha>
  • Generates Markdown warning if a PR removes or renames feature files; used in CI (requires GITHUB_TOKEN).

• All tests: npm test -- src/data-directory/tests
• Targeted:
  • Schemas: npm test -- src/data-directory/tests/data-schemas.ts
  • Orphans: npm test -- src/data-directory/tests/orphaned-features.ts
  • Loader basics: npm test -- src/data-directory/tests/get-data.ts

• File locations: Everything under data/ (English and localized mirrors). Reusables/variables/ui are read via dotted paths (reusables.foo.bar, variables.product.prodname_ghe_server, ui.pages.home).
• Markdown in data: Frontmatter is stripped by gray-matter; content is trimmed.
• Downstream consumers:
  • Liquid tags: content-render/liquid/data.ts, indented-data-reference.ts
  • Content linter: content-linter/lib/linting-rules/liquid-data-tags.ts, frontmatter-intro-links.ts
  • Server: app/lib/app-router-context.ts, app/lib/server-context-utils.ts
  • Metrics/tests: content-render/tests, content-linter/tests/site-data-references.ts
• Translation notes:
  • Fallbacks ensure missing localized YAML/MD reads from English.
  • Specific files are forced-English to avoid corrupt translations (see constants in get-data.ts).

• Ensure data/ exists relative to project root; schemas auto-scan data/tables at runtime.
• Set DEBUG_JIT_DATA_READS=true to log every on-disk read from the data loaders; useful alongside tests or local runs to trace which data files are touched.
• When adding a new data directory:
  • Prefer YAML for structured data; add schema if shape matters to correctness.
  • Add README under data/<dir>/ when introducing new contracts.
  • Update manualSchemas if not a table.

• Primary: Docs Engineering.
• Content changes: Docs Content (docs-content).

• Current state: KTLO; minimal changes expected. Update this README when touching data loaders, schemas, or scripts.
• Next steps: Keep the schema registry aligned with new data shapes and rerun npm test -- src/data-directory/tests when data contracts change.