sequence-builder

SequenceForge

A single-file, zero-dependency UML sequence diagram builder.
Runs entirely in the browser. No build step. npm install only for Playwright render tests.

Live demo — v0.9.93

All releases

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Quick start

git clone https://github.com/MeatPopSci1972/sequence-builder
cd sequence-builder
node launcher.js        # dev server with hot-reload at http://localhost:3799

Open http://localhost:3799 in your browser.

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What it does

Capabilities pinned by the contract test suites:

• Suite 1 — REFLOW_ACTORS tests
• Suite 2 — DELETE_ACTOR cascade
• Suite 3 — UPDATE_MESSAGE partial patch
• Suite 4 — meta.undoable = false
• Suite 5 — UNDO
• Suite 6 — REDO
• Suite 7 — _parseUML (PlantUML + Mermaid parser)
• Suite 8 — End-to-End scenario
• Suite 9 — UI geometry contracts & proto2prod guard rails
• Suite 10 — ADD_MESSAGE null contract
• Suite 11 — Message label contract & inline edit
• Suite 12 — autoFitOnLoad preference
• Suite 13 — Fragment geometry contracts
• Suite 14 — Canvas pan & arrow-key nudge contracts
• Suite 15 — Properties bag contracts
• Suite 16 — Regex contract tests

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Repository structure

File	Notes
LICENSE
README.md
build.js
launcher.js
lint.js
log.html
package.json
sequence-builder.html
sequence-builder.store.js
sequence-builder.test.js
sf-endpoints.js
sf-preflight.ps1
sf-readme-gen.js
sf-server.js
themes.json

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Dev server API

Served by sf-server.js via launcher.js on port 3799.

Method	Path	Description
GET	/status	Session bootstrap — version, git, demos
GET	/HANDOFF.md	Session handoff doc
GET	/api	Endpoint reference JSON (this)
GET	/usage	AI usage guide plain text
GET	/log	Server event log JSON
GET	/git-log	git log –oneline JSON. Default n=20
GET	/test	Run build+tests — returns HTML report
GET	/test-render	Playwright render gate — 3 demos x 5 SVG layers
GET	/validate-readme	Check README link+label for vX.Y.Z. Returns {ok,hasLink,hasLabel}
GET	/slice	Return named sentinel section of a file. No section = manifest
POST	/generate-readme	Generate README.md from live sources — git, test suites, endpoints, version
POST	/build	Run build.js — sync store.js into HTML
POST	/lint	Run lint.js — button count, SVG balance, sentinels
POST	/patch	Find-replace in file. Body:{file,anchor,replace}. Flex whitespace matching. Returns {ok,replaced,length}
POST	/git	git add -A && commit. Body:{message}
POST	/git-restore	Restore tracked file to HEAD. Body:{file}
POST	/tag	Create annotated git tag. Body:{tag,message}
POST	/changelog	Auto-gen CHANGELOG.md from git log since last tag. Body:{version}
POST	/update-handoff	Populate live fields in HANDOFF.md from status+test+test-render
POST	/snapshot?v=X.Y.Z	Copy build+HANDOFF to releases/vX.Y.Z/
GET	/<file>	Read any file in repo root
PUT	/<file>	Write any file in repo root. ?verify=1 returns {ok,wrote,status}

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Running the tests

node build.js && node sequence-builder.test.js
# Expected: 127 passed | 0 failed | 127 total

Or via the dev server: GET http://localhost:3799/test

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Tech stack

Vanilla JS, SVG, HTML5 Canvas. No frameworks, no bundler, no runtime dependencies.

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License

MIT

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