exercise-testing

name	exercise-testing
description	Comprehensive validation for Pixels2GenAI v2 lessons. Use when validating ported v1 Python scripts, checking copied lesson assets, type-checking MDX frontmatter, running the Astro build, or performing quality audits on a lesson. Activate after porting a lesson, before marking a lesson as shipped, or when debugging build/render errors.

Lesson Testing & Validation Skill (v2)

Skill Overview

This skill provides comprehensive validation protocols for v2 lessons. A "lesson" in v2 is the combination of an MDX file under src/content/lessons/, the assets it references under public/lesson-media/<lesson-path>/, and the leaf entry in src/data/curriculum/subtopics.ts. Validation makes sure every layer is consistent before the lesson goes live.

Path convention — <lesson-path> means the v1-mirrored relative path Module_NN_<topic>/X.Y_<subtopic>/X.Y.Z_<exercise>: the MDX is the file src/content/lessons/<lesson-path>.mdx, its assets sit in the folder public/lesson-media/<lesson-path>/, and the page URL is /lessons/<id> (numeric leaf id). npm run check validates all of this wiring automatically — run it first.

When to Use This Skill

• After porting a v1 lesson (RST → MDX) — use alongside the lesson-port skill
• After authoring a new MDX lesson from scratch
• Before marking a lesson as shipped (i.e. before adding lessonSlug in subtopics.ts)
• When debugging build / render errors
• During quality assurance reviews

Testing Hierarchy

Level 1: Source Python Execution      (MUST PASS for ported lessons)
    ↓
Level 2: Asset Migration & Validation (MUST PASS)
    ↓
Level 3: MDX Frontmatter + Content    (MUST PASS)
    ↓
Level 4: Astro Build + Render         (MUST PASS)
    ↓
Level 5: Quality Audit                (CHECKLIST)

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Level 1: Source Python Execution

Goal: Verify the v1-source Python scripts still execute, since their outputs are the static images embedded in the v2 lesson.

This applies only when porting a lesson from v1. For lessons authored natively in v2, skip to Level 2.

Manual Testing

# Navigate to the v1 exercise directory
$v1 = "C:\Users\User\Desktop\git-repos\numpy-to-genAI"
Set-Location "$v1\content\Module_XX_topic\X.Y_subtopic\X.Y.Z_exercise"

# Activate the v1 venv (Python 3.11.9)
& "$v1\.venv\Scripts\Activate.ps1"

# Run each script
python exercise1_execute.py
python exercise2_modify.py
python exercise3_create.py
# Exit code 0 = pass

Common Source Errors

ModuleNotFoundError — venv missing a dependency. Compare against <v1>\requirements.txt.

FileNotFoundError — script depends on a relative path. Confirm the working directory matches the exercise folder.

Array dimension mismatch — usually a NumPy version skew between v1's venv and a fresh Python.

If a v1 script fails, do not silently fix it in v1 (v1 is treated as read-only). Instead: document the failure, port the current working output PNG/GIF, and either skip the broken example in the MDX or write a v2-equivalent script under public/lesson-media/<lesson-path>/.

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Level 2: Asset Migration & Validation

Goal: Verify that every image, GIF, and downloadable .py referenced from the MDX exists under public/lesson-media/<lesson-path>/.

Step 2.1 — Run the migrator

The migrator is inventory-driven (docs/reports/migration-inventory.json); run it for the lesson under test:

npm run copy-assets -- --only=<id>

The script copies PNG/GIF/JPG/SVG/PY/PTH/TXT into public/lesson-media/<lesson-path>/ and is idempotent — re-running overwrites destination files. It deliberately skips README.rst because the MDX hand-port is canonical.

Step 2.2 — Cross-reference MDX assets

For every src="/lesson-media/<lesson-path>/…" in the MDX, verify the file exists:

# Inside the lesson dir, list everything that was copied
Get-ChildItem -Recurse "public/lesson-media/<lesson-path>/"

Then grep the MDX for every /lesson-media/ reference and confirm each filename appears in the directory listing (npm run check does exactly this across all lessons).

Step 2.3 — Image sanity checks

For each PNG / GIF / JPG in public/lesson-media/<lesson-path>/:

• Opens cleanly (no zero-byte / truncated files)
• File size <= 500 KB for PNGs, <= 2 MB for GIFs (see docs/references/visual-guidelines.md)
• Dimensions between 10×10 and 4096×4096

Quick PowerShell check:

Get-ChildItem "public/lesson-media/<lesson-path>/*.png" | ForEach-Object {
  $kb = [math]::Round($_.Length / 1KB, 1)
  "$($_.Name): $kb KB"
}

Checklist

• All <Figure src=…> paths resolve under public/lesson-media/<lesson-path>/
• All <Download href=…> paths resolve under public/lesson-media/<lesson-path>/
• Image file sizes within budget
• No leftover __pycache__, .pyc, .ipynb_checkpoints in public/lesson-media/<lesson-path>/
• Model-weight files (.pth) intentionally excluded if large (e.g. fabric dataset in 12.1.2)

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Level 3: MDX Frontmatter + Content

Goal: Verify the MDX file is valid against the Zod schema in src/content/config.ts and uses the custom MDX components correctly.

Step 3.1 — Frontmatter schema check

The schema (in src/content/config.ts) requires:

---
module: "M 04"             # display label
cycle: "I"                  # I | II | III
title: "Fractal Square"
objective: "One-sentence italic lead."
framework: "hands-on"       # hands-on | conceptual | hybrid | project
duration: "20–25 min"
level: "beginner"           # beginner | beginner-intermediate | intermediate | intermediate-advanced | advanced
load: "3 core concepts"     # optional
prereqs: "Basic Python"     # optional
prev: { slug: "1.1.1", title: "Images as Arrays & RGB" }  # or null
next: { slug: "12.1.2", title: "DCGAN Art" }              # or null
backLink: { href: "/#curriculum", label: "Back to Curriculum" }  # optional
---

The build fails fast if any required field is missing or has the wrong shape — npm run build is the authoritative check (Astro runs Zod under the hood).

Step 3.2 — Custom component sanity

Required components (defined in src/components/lesson/):

Component	Usage
<CodeBlock lang="python" file="…">	Wraps fenced code blocks
<Admonition type="tip|note|important|dyk" title="…">	Pull-out boxes; dyk = "Did You Know" but PREFER a specific title
<Figure src=… alt=… caption=… num={N} role="diagram|output">	All images
<Exercise n={1} kicker="EXECUTE" title="…">	Exercise wrappers (kickers: EXECUTE, MODIFY, CREATE)
<Dropdown summary="…">	Collapsible hint/solution blocks
<Download href=… label=…>	Asset download links

Step 3.3 — Sectionize check

The Astro config (astro.config.mjs) auto-wraps content between ## h2 headings into <section class="lesson-section">. Confirm:

• Lesson has clear ## h2 headings (typically: Overview, Quick start, Core concepts, Exercises, Downloads, Summary, References)
• Content before the first h2 (e.g. an opening <Figure>) is intentional — it stays unwrapped at article level

Content Completeness Checklist (matches scaffolding-rules.md)

Hands-on (F1) lessons must have:

• Overview (anchor #overview)
• Learning objectives (<ol class="obj-list">)
• Quick start (#quick-start) with a runnable snippet and visible output
• Core concepts (#core-concepts) — 2-3 concepts
• Exercises (#exercises) — Execute / Modify / Create using <Exercise> wrappers
• Downloads (#downloads)
• Summary (#summary)
• References (#references) — <section class="refs"> with <ol>

Conceptual (F2) lessons must have:

• Big Question (or hook paragraph)
• Learning path overview
• Part 1-3 sections with theory + code
• Exercises (Execute / Modify / Create)
• Synthesis project
• Summary + References (7-10 citations)

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Level 4: Astro Build + Render

Goal: Verify the lesson builds, renders, and is reachable.

Step 4.1 — Full build

npm run build

Look for:

• Zero MDX compilation errors
• Zero broken <Figure src=…> paths (npm run check fails the build if a /lesson-media/… file is missing from public/)
• TypeScript strict passes (@astrojs/check runs as part of build)
• Output written to dist/lessons/<slug>/index.html

Step 4.2 — Dev server render

npm run dev

Open http://localhost:4321/lessons/<slug> and verify:

• Page loads with no console errors
• All figures display (right-click → "open in new tab" any that look broken)
• All <Dropdown> blocks expand
• All <CodeBlock> blocks render with the dual-theme Shiki highlighting
• The lesson-section side-rail (manuscript-margin gloss) tracks each <h2> section
• The stage tracker shows the right module window (driven by module: frontmatter)
• prev / next navigation links resolve to existing lessons

Step 4.3 — Lighthouse / accessibility quick check (optional)

In Chrome DevTools, run Lighthouse on the rendered page. Watch for missing alt text on images — every <Figure> should have a meaningful alt.

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Level 5: Quality Audit

Goal: Comprehensive review of content quality.

Pedagogical Quality Checklist (from CLAUDE.md)

• Tone: Academic yet friendly (no emojis)
• Author attribution: Source .py files credit "Pixels2GenAI Project", never "Claude"
• Citations: Min 5-7 (Modules 0-6) or 7-10 (Modules 7-15); APA 7th edition; rendered in <section class="refs">
• Accuracy: Technical information correct (cross-check against module references)
• Clarity: Concepts explained without jargon overload
• Completeness: Follows appropriate framework template (F1 / F2 / F1+F2 / F3)
• Scaffolding: Exercises progress Execute → Modify → Create
• Visual examples: Every Core Concept has at least one figure
• Accessibility: Descriptive alt text on every <Figure>
• Duration: Within target range for the module (see duration-guidelines.md)
• Cognitive load: ≤ 3-4 new concepts across the lesson

Code Quality Checklist (for downloadable .py files)

• Simplicity — no unnecessary complexity
• Comments explain "why", not "what"
• Humanized variable names (pixel_color not pc)
• dtype=np.uint8 for image arrays
• Only dependencies from v1's requirements.txt
• Reasonable execution time (< 30 s for most lessons)
• Reproducible (random seeds set where relevant)

AI-pattern check

Before final approval, run the ai-revision skill against the MDX file. Aim for overall risk LOW or MINIMAL.

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Success Criteria

A lesson is ready to ship (i.e. ready to receive its lessonSlug in src/data/curriculum/subtopics.ts) when:

1. ✅ Source Python scripts execute cleanly (Level 1 — for ported lessons)
2. ✅ Assets are copied and every MDX reference resolves (Level 2)
3. ✅ MDX is schema-valid and uses components correctly (Level 3)
4. ✅ npm run build succeeds with no errors or asset warnings (Level 4)
5. ✅ Dev-server render passes visual + interaction checks (Level 4)
6. ✅ Content meets pedagogical and AI-pattern quality bars (Level 5)

Only then should you update src/data/curriculum/subtopics.ts to add lessonSlug for the leaf, and src/data/curriculum/modules.ts to update firstLesson if this is the module's first ported lesson.

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Use the lesson-port skill for the porting workflow itself and ai-revision for the prose quality pass. This skill is the gate that ensures everything fits together before going live.