init: default db:generate to --pglite

Fixes #2

Scaffolded db:generate previously ran 'pgstrap generate', which requires
a running Postgres instance. Running 'bun run db:generate' on a fresh
project would fail with a connection error.

Default to '--pglite' so type generation works out of the box against an
in-memory PGlite instance. Users who need to generate against a real
Postgres (e.g. via DATABASE_URL) can drop the flag from the scaffolded
script.

- src/init.ts: scaffold db:generate with --pglite
- tests/init.test.ts: assert the new default and add a regression test
- README.md: document the new default

/claim #2

Author: js-opus

README.md

@@ -55,7 +55,7 @@ npm install pgstrap --save-dev
 
 - `npm run db:migrate` - Run pending migrations
 - `npm run db:reset` - Drop and recreate the database, then run all migrations
-- `npm run db:generate` - Generate types and structure dumps. Use `pgstrap generate --pglite` to run migrations against an in-memory PGlite instance.
+- `npm run db:generate` - Generate types and structure dumps. Defaults to an in-memory PGlite instance, so no Postgres needs to be running. To generate against a real Postgres (e.g. via `DATABASE_URL`), edit the script and drop `--pglite`.
 - `npm run db:create-migration` - Create a new migration file
 
 ### Configuration

src/init.ts

@@ -16,7 +16,10 @@ export const initPgstrap = async (ctx: Pick<Context, "cwd">) => {
 
   pkg.scripts["db:migrate"] = "pgstrap migrate"
   pkg.scripts["db:reset"] = "pgstrap reset"
-  pkg.scripts["db:generate"] = "pgstrap generate"
+  // Default `db:generate` to PGlite so `bun run db:generate` doesn't require
+  // a Postgres instance running in the background. To generate against a real
+  // Postgres connection (e.g. DATABASE_URL), drop `--pglite` from this script.
+  pkg.scripts["db:generate"] = "pgstrap generate --pglite"
   pkg.scripts["db:create-migration"] = "pgstrap create-migration"
 
   if (!pkg.devDependencies) pkg.devDependencies = {}

tests/init.test.ts

@@ -25,6 +25,16 @@ test("initPgstrap writes scripts to package.json", async () => {
   )
   expect(pkg.scripts["db:migrate"]).toBe("pgstrap migrate")
   expect(pkg.scripts["db:reset"]).toBe("pgstrap reset")
-  expect(pkg.scripts["db:generate"]).toBe("pgstrap generate")
+  // db:generate defaults to --pglite so users don't need Postgres running
+  // in the background to regenerate types/structure. See issue #2.
+  expect(pkg.scripts["db:generate"]).toBe("pgstrap generate --pglite")
   expect(pkg.scripts["db:create-migration"]).toBe("pgstrap create-migration")
 })
+
+test("initPgstrap defaults db:generate to PGlite (no Postgres needed)", async () => {
+  await initPgstrap({ cwd: testDir })
+  const pkg = JSON.parse(
+    fs.readFileSync(path.join(testDir, "package.json"), "utf8"),
+  )
+  expect(pkg.scripts["db:generate"]).toContain("--pglite")
+})