test(ci): Test Prisma migrations (#160)

* ci: Test Prisma migrations

* docs: Explain migration progress

* docs: Clarify create-only migration

package.json

@@ -13,10 +13,11 @@
     "test": "jest",
     "test:watch": "jest --watch",
     "test:coverage": "jest; open ./coverage/lcov-report/index.html",
-    "prisma:pull": "dotenv -e .env.local npx prisma db pull",
+    "prisma:pull": "dotenv -e .env.local -- npx prisma db pull",
     "prisma:generate": "prisma generate",
-    "prisma:migrate": "dotenv -e .env.local npx prisma migrate dev",
-    "prisma:studio": "dotenv -e .env.local npx prisma studio",
+    "prisma:migrate": "dotenv -e .env.local -- npx prisma migrate dev",
+    "prisma:migrate-create-only": "dotenv -e .env.local -- npx prisma migrate dev --create-only",
+    "prisma:studio": "dotenv -e .env.local -- npx prisma studio",
     "postinstall": "npm run prisma:generate",
     "prettier": "prettier --write .",
     "prepare": "husky",

prisma/docs/how-to-update-prisma-schema.md

@@ -0,0 +1,24 @@
+## How to update Fairhold's Prisma schema
+
+This guide explains how we can update our Prisma schema and manage migrations to the production database. This highlights the steps we need to take within this repo, for a wider primer please see the Prisma docs: https://www.prisma.io/docs/orm/prisma-migrate
+
+
+1. Update `schema.prisma`
+Make a change to this file which describes the change you would like to make (e.g. add column, add table).
+
+2. Generate migration
+Run `npm run prisma:migrate` - this will apply to the change to your local dev database, and generate a migration file in `/prisma/migrations`
+
+> [!TIP]
+> The command `npm run prisma:migrate-create-only` will generate a migration file without running it. This is helpful if you want to add any additional changes, and manually configure the migration. 
+> 
+> For example when renaming a column Prisma may drop and recreate the column (thus losing data). Manually writing the correct SQL in the generated migration file (e.g. `ALTER table UPDATE column`) allows us to work around this. You'll then need to run `npm run prisma:migrate` to apply your changes.
+>
+> Docs: https://www.prisma.io/docs/orm/prisma-migrate/workflows/development-and-production#customizing-migrations
+
+1. Update Prisma client
+Run `npm run prisma:generate` to update your local client. You should now be able to both interact with the updated Prisma client as well as view the change in your local dev database.
+
+1. Open PR, merge to `main`
+From here, we can open the changes up to peer-review on GitHub. Once approved and merged, CI will apply our new migration to the production database using the "Deploy migrations" action (dir: `/.github/workflows/deploy-migrations.yaml`).
+

prisma/migrations/20241206120523_rename_buildprices/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE "buildprices" 
+RENAME COLUMN "housetypedescription" TO "house_type_description";

prisma/schema.prisma

@@ -10,7 +10,7 @@ datasource db {
 
 model BuildPrices {
   id                   Int     @id @default(autoincrement())
-  houseTypeDescription String? @map("housetypedescription") @db.VarChar(250)
+  houseTypeDescription String? @map("house_type_description") @db.VarChar(250)
   houseType            String? @map("housetype") @db.VarChar(1)
   priceRange           String? @map("pricerange") @db.VarChar(50)
   priceMid             Float?  @map("pricemid")