E01 · F01 · US-001 — Rectangle contour from width and height

As a symbol designer, I want a rectangle defined by an integer width and height so that its contour is exact and reproducible.

Acceptance criteria

• Given width 100 and height 50, when the contour is built, then its vertices are (0, 0), (100, 0), (100, 50), (0, 50): clockwise on screen from the top-left vertex (Q11).
• Given any integer width and height, when the contour is built, then every vertex has integer coordinates (ADR-0003).
• Given width 0 or height 0, when the contour is built, then the degenerate rectangle is accepted (Q15).
• Given a negative width or height, when the rectangle is created, then it is rejected (Q15).

Tasks

One task = one commit, referenced as US-001.Tn.

• T1 — Write the tests of the cases above (1 h)
• T2 — Add the Point type module in src/math/ (0.5 h)
• T3 — Add the rectangle model type and its contour function (domain) in src/model/ (2 h) — Rectangle, rectangleContour, isValidRectangle
• T4 — Re-export the new layers from src/index.ts (npm run fix) (0.5 h)