de-roadmap/AGENTS.md

Repository Guidelines

Project Structure & Module Organization

• Root README.md describes the learning roadmap (RU) and serves as the main page of the MkDocs site.
• dwh-modeling/ contains the article and demo DWH model; SQL lives in dwh-modeling/sql as ordered scripts 01_...sql–09_...sql (07–09 are homework DDL, template and solution).
• postgres-bookings/ is a Dockerized PostgreSQL + demo “bookings” DB; start it first, then apply DWH scripts against the demo database.
• mkdocs.yml — MkDocs Material config; docs_dir: . (repo root = site root). Excluded dirs: project/, postgres-bookings/, .github/, .claude/.
• .github/workflows/deploy-site.yml — CI/CD: push to main → build → deploy to GitHub Pages.
• project/ — PRD and ADR (excluded from site).

Build, Test, and Development Commands

• Start demo Postgres:
  cd postgres-bookings && bash download_db.sh && docker compose up -d
• Open psql inside the container:
  cd postgres-bookings && ./psql_sh
• Apply DWH schema from the repo root (after Postgres is up):
  psql -h 127.0.0.1 -p 5432 -U postgres -d demo -f dwh-modeling/sql/01_ddl_stg-dds.sql
• Stop and reset the cluster when needed:
  cd postgres-bookings && docker compose down -v

Coding Style & Naming Conventions

• SQL: PostgreSQL dialect, uppercase keywords, snake_case identifiers, 4-space indentation, and concise comments (-- ...).
• SQL files: keep numeric prefixes (01_, 02_, …) to reflect execution order and use descriptive suffixes like ddl_* / dml_*.
• Shell: target bash, prefer simple, POSIX-friendly constructs; mirror the style of existing scripts in postgres-bookings/.

Markdown Style (dual-compatible: GitHub + MkDocs Material)

All .md files MUST render correctly on both GitHub and the MkDocs Material site. Follow these rules:

Headings:

• README.md (root): start from ## (H2). Do NOT use # (H1) — MkDocs uses H1 as page title, multiple H1s break the right-sidebar TOC.
• dwh-modeling/*.md: may use # (H1) since each file is a separate page on the site.

Lists:

• Always leave a blank line before the first list item after a paragraph, heading, or any non-list text. Python-Markdown (MkDocs) requires this; GitHub tolerates its absence but blank lines don't hurt.
• Use 4-space indentation for nested lists (not 2-space). GitHub supports both, Python-Markdown requires 4.
• Example:

  Some introductory text:
  
  - Item one
  - Item two
      - Nested item (4 spaces)
  

Links:

• Internal links: always use relative paths to .md files: [text](dwh-modeling/SCD.md). MkDocs resolves them automatically.
• Anchor links: use lowercase slugs with single hyphens. Avoid em-dash — in headings (it produces -- in MkDocs slugs vs - on GitHub). Use commas or colons instead.

Special characters in headings:

• OK: colons :, commas ,, parentheses (), guillemets «» — stripped equally by both platforms.
• Avoid: em-dash —, en-dash – — slug behavior differs between GitHub and MkDocs.

MkDocs Site Commands

• Local preview (user starts, ask user to run via !): uv run --with 'mkdocs-material==9.6.14' --with 'mkdocs-same-dir==0.1.3' mkdocs serve
• Build with strict validation (catches broken links/anchors): uv run --with 'mkdocs-material==9.6.14' --with 'mkdocs-same-dir==0.1.3' mkdocs build --strict
• Visual check via Playwright (when mkdocs serve is running on port 8000): npx playwright screenshot --viewport-size='1280,800' 'http://127.0.0.1:8000/#anchor' /path/to/screenshot.png Then read the screenshot with the Read tool to inspect rendering. Use --viewport-size='1280,2000' for tall pages.
• Kill stuck dev server: lsof -ti :8000 | xargs kill
• Site URL: https://de.dementev.space/ (старый адрес https://dementev-dev.github.io/de-roadmap/ отдаёт 404)

Testing Guidelines

• There is no dedicated test framework; treat SQL scripts as executable documentation.
• For dwh-modeling/sql, run scripts sequentially and rerun 04_validation.sql after changes to ensure the demo model still loads and basic checks pass.
• For postgres-bookings, after modifications run docker compose up -d && ./psql_sh and verify simple queries such as SELECT COUNT(*) FROM bookings.flights;.

Commit & Pull Request Guidelines

Required: Read COMMIT_RULES.md before making commits.

Pull requests should focus on one topic, include a brief context, list of changes, and manual steps to reproduce or validate (commands you ran, expected results).

Security & Configuration Tips

• Do not commit personal .env files or credentials; use local overrides only.
• Demo credentials and ports in postgres-bookings are for local training only—never reuse them in shared or production environments.