SidewalkWebpage evolutions.instructions.md

Play evolution (schema) review — highest-value checks

• One evolution file per PR. Flag a PR minting a new-numbered file when its changes could fold into the PR's existing evolution.
• Owner: every CREATE TABLE must be followed by ALTER TABLE <name> OWNER TO sidewalk; in the same file. Flag any missing it. Tables ONLY — not enum types, views, or standalone sequences; SERIAL/identity sequences are covered automatically by the table's owner change.
• Full constraints — don't lean on the app. For each new/altered table flag missing: NOT NULL on never-null columns, UNIQUE/PK on natural keys & 1:1 relationships, a FOREIGN KEY for every reference, a CHECK for bounded domains (severity 1–3, non-negative counts, 0–1 fractions, valid lat/lng). Each must be mirrored in the Slick model.
• Closed value sets: prefer a Postgres enum type (high-row / runtime-written / Scala-mirrored columns) or a CHECK (col IN (...)) (tiny config tables) over a lookup table or bare text. When an enum replaces a same-named lookup table, DROP TABLE must precede CREATE TYPE.
• Renames leave fossils. An evolution renaming a table/column must also ALTER TABLE ... RENAME CONSTRAINT / ALTER INDEX ... RENAME every constraint and index embedding the old name (to <table>_<column>_{fkey,key,pkey,check}) and update the Slick name string. Flag a rename that omits this.
• Parser trap: no ; inside a -- comment — Play's evolution parser splits statements on ; and will break. Flag it.
• Both # --- !Ups and # --- !Downs sections must be present.