ECC/docs/testing/plan-canvas-pdf-export.tdd.md

Plan Canvas PDF export TDD evidence

User journey

As a Plan Canvas reviewer, I can select Download PDF and receive the current artifact as a real PDF file without sending the plan to an external converter.

Guarantees

Guarantee	Evidence	Result
The Canvas exposes a labeled PDF download action	Server integration test and browser accessibility tree	PASS
The browser fetches a PDF, creates a Blob URL, and starts a named download	Generated-client integration test and real Chrome interaction	PASS
Only a loopback artifact URL can reach the renderer	assertLoopbackUrl tests	PASS
Filenames are useful and safe across platforms	pdfFileName tests	PASS
Incomplete output is never served as a PDF	%PDF header and %%EOF completion tests	PASS
Renderer state is private and temporary	Fake-process lifecycle test and live process/temp-state inspection	PASS
Export adds no cloud converter or npm runtime dependency	Implementation and package diff inspection	PASS

Red and green

• RED: the focused server suite produced 30 passes and 2 failures because the Canvas had no Download PDF control or PDF endpoint.
• GREEN: renderer unit tests pass 6/6, Plan Canvas server tests pass 32/32, and the end-to-end review workflow passes 10/10.
• FULL SUITE: npm test passes all 4,003 discovered tests; full ESLint, Markdown lint, package dry-run, and git diff --check also pass.
• COVERAGE: npm run coverage passes 4,003/4,003 with 88.97% statements, 80.58% branches, 94.22% functions, and 88.97% lines. The Plan Canvas module group reaches 96.72% statements and lines, 84.47% branches, and 95.34% functions.
• BROWSER: Chrome selected Download PDF on the real Sandbox Execution Fabric. The request returned HTTP 200, application/pdf, and downloaded EXECUTION-FABRIC.pdf to the browser's download directory.
• DOCUMENT: the downloaded Sandbox PDF is a valid PDF 1.4 document with five pages. The ECC 2 to ECC 3 master plan exports as a valid eight-page PDF. The HTML release-preview artifact exports as a valid four-page PDF. Rendered first-page previews retain headings, body text, tables/code styling, and print-safe light colors.

Runtime contract

The loopback server discovers Google Chrome, Chromium, or Microsoft Edge, or uses ECC_PLAN_CANVAS_CHROME_PATH. It launches the executable without a shell, with a private temporary profile and a loopback-only artifact URL. Completion requires both a %PDF- header and %%EOF marker. The renderer is terminated and temporary state is removed before the response is handed to the browser.

If no renderer exists, the browser receives an actionable local error. Plan Canvas does not upload the artifact or add a hosted conversion dependency.