Default generate to PGlite

README.md

@@ -3,7 +3,7 @@
 [![npm version](https://badge.fury.io/js/pgstrap.svg)](https://badge.fury.io/js/pgstrap)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 
-pgstrap allows you to easily run typescript migrations or generate a directory that represents your database schemas with `table.sql` files. Run `pgstrap generate` to generate a directory with the structure of your postgres database schemas!
+pgstrap allows you to easily run typescript migrations or generate a directory that represents your database schemas with `table.sql` files. Run `pgstrap generate` to generate a directory with the structure of your postgres database schemas. Type generation uses PGlite by default, so Postgres does not need to be running locally.
 
 ## Features
 
@@ -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 with an in-memory PGlite database by default. Use `pgstrap generate --no-pglite` to generate from an external Postgres database configured by `DATABASE_URL`.
 - `npm run db:create-migration` - Create a new migration file
 
 ### Configuration

src/cli.ts

@@ -35,10 +35,18 @@ import { getProjectContext } from "./get-project-context"
     "generate",
     "generate types and sql documentation from database",
     (yargs) => {
-      yargs.option("pglite", { type: "boolean", default: false })
+      yargs.option("pglite", {
+        type: "boolean",
+        default: true,
+        describe:
+          "run migrations in an in-memory PGlite database before generating types",
+      })
     },
     async (argv) => {
-      generate({ ...(await getProjectContext()), pglite: !!argv.pglite })
+      await generate({
+        ...(await getProjectContext()),
+        pglite: argv.pglite !== false,
+      })
     },
   )
   .parse()

src/generate.ts

@@ -1,18 +1,28 @@
 import * as zg from "zapatos/generate"
-import {
-  getConnectionStringFromEnv,
-  getPgConnectionFromEnv,
-} from "pg-connection-from-env"
+import { getConnectionStringFromEnv } from "pg-connection-from-env"
 import { Context } from "./get-project-context"
 import { dumpTree } from "pg-schema-dump"
 import path from "path"
 import { migrate } from "./migrate"
 
+const restoreDatabaseUrl = (previousDatabaseUrl: string | undefined) => {
+  if (previousDatabaseUrl === undefined) delete process.env.DATABASE_URL
+  else process.env.DATABASE_URL = previousDatabaseUrl
+}
+
+const closeServer = async (server: import("node:net").Server) => {
+  if (!server.listening) return
+
+  await new Promise<void>((resolve) => {
+    server.close(() => resolve())
+  })
+}
+
 export const generate = async ({
   schemas,
   defaultDatabase,
   dbDir,
-  pglite = false,
+  pglite = true,
   migrationsDir,
 }: Pick<Context, "schemas" | "defaultDatabase" | "dbDir"> & {
   pglite?: boolean
@@ -27,65 +37,71 @@ export const generate = async ({
     const net = await import("node:net")
 
     const db = new PGlite()
+    const previousDatabaseUrl = process.env.DATABASE_URL
+    let server: import("node:net").Server | undefined
 
-    await migrate({
-      client: db as any,
-      migrationsDir,
-      defaultDatabase,
-      cwd: process.cwd(),
-      schemas,
-    })
-
-    const server = net.createServer(async (socket) => {
-      const connection = await fromNodeSocket(socket, {
-        serverVersion: "16.3 (PGlite)",
-        auth: {
-          method: "password",
-          validateCredentials: ({ username, password }: any) =>
-            username === "postgres" && password === "postgres",
-          getClearTextPassword: () => "postgres",
-        },
-        async onStartup() {
-          await (db as any).waitReady
-        },
-        async onMessage(data: Uint8Array, { isAuthenticated }: any) {
-          if (!isAuthenticated) return
-          try {
-            const { data: responseData } = await (db as any).execProtocol(data)
-            return responseData
-          } catch {
-            return undefined
-          }
-        },
+    try {
+      await migrate({
+        client: db as any,
+        migrationsDir,
+        defaultDatabase,
+        cwd: process.cwd(),
+        schemas,
       })
-    })
 
-    await new Promise<void>((resolve) => server.listen(0, resolve))
-    const port = (server.address() as any).port
-    const connectionString = `postgres://postgres:postgres@127.0.0.1:${port}/postgres`
+      const activeServer = net.createServer(async (socket) => {
+        await fromNodeSocket(socket, {
+          serverVersion: "16.3 (PGlite)",
+          auth: {
+            method: "password",
+            validateCredentials: ({ username, password }: any) =>
+              username === "postgres" && password === "postgres",
+            getClearTextPassword: () => "postgres",
+          },
+          async onStartup() {
+            await (db as any).waitReady
+          },
+          async onMessage(data: Uint8Array, { isAuthenticated }: any) {
+            if (!isAuthenticated) return
+            try {
+              const { data: responseData } = await (db as any).execProtocol(
+                data,
+              )
+              return responseData
+            } catch {
+              return undefined
+            }
+          },
+        })
+      })
+      server = activeServer
 
-    const prevDbUrl = process.env.DATABASE_URL
-    process.env.DATABASE_URL = connectionString
+      await new Promise<void>((resolve) => activeServer.listen(0, resolve))
+      const port = (activeServer.address() as any).port
+      const connectionString = `postgres://postgres:postgres@127.0.0.1:${port}/postgres`
 
-    await zg.generate({
-      db: {
-        connectionString,
-      },
-      schemas: Object.fromEntries(
-        schemas.map((s) => [s, { include: "*", exclude: [] }]),
-      ),
-      outDir: dbDir,
-    })
+      process.env.DATABASE_URL = connectionString
 
-    await dumpTree({
-      targetDir: path.join(dbDir, "structure"),
-      defaultDatabase: "postgres",
-      schemas,
-    })
+      await zg.generate({
+        db: {
+          connectionString,
+        },
+        schemas: Object.fromEntries(
+          schemas.map((s) => [s, { include: "*", exclude: [] }]),
+        ),
+        outDir: dbDir,
+      })
 
-    server.close()
-    if (prevDbUrl === undefined) delete process.env.DATABASE_URL
-    else process.env.DATABASE_URL = prevDbUrl
+      await dumpTree({
+        targetDir: path.join(dbDir, "structure"),
+        defaultDatabase: "postgres",
+        schemas,
+      })
+    } finally {
+      restoreDatabaseUrl(previousDatabaseUrl)
+      if (server) await closeServer(server)
+      await (db as any).close?.()
+    }
     return
   }
 

tests/generate.pglite.test.ts

@@ -13,35 +13,82 @@ exports.down = async (pgm) => {
 }
 `
 
-test("generate with pglite runs migrations and dumps structure", async () => {
+test("generate defaults to pglite and dumps structure without postgres", async () => {
   const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "pgstrap-generate-"))
   const migrationsDir = path.join(tmp, "migrations")
+  const previousDatabaseUrl = process.env.DATABASE_URL
+
   fs.mkdirSync(migrationsDir, { recursive: true })
   fs.writeFileSync(
     path.join(migrationsDir, "001_create_table.js"),
     migrationFile,
   )
 
-  await generate({
-    schemas: ["public"],
-    defaultDatabase: "postgres",
-    dbDir: path.join(tmp, "db"),
-    migrationsDir,
-    pglite: true,
-  })
-
-  const zapatosFile = path.join(tmp, "db", "zapatos", "schema.d.ts")
-  const structureDir = path.join(
-    tmp,
-    "db",
-    "structure",
-    "public",
-    "tables",
-    "foo",
+  process.env.DATABASE_URL = "postgres://postgres:postgres@127.0.0.1:1/missing"
+
+  try {
+    await generate({
+      schemas: ["public"],
+      defaultDatabase: "postgres",
+      dbDir: path.join(tmp, "db"),
+      migrationsDir,
+    })
+
+    const zapatosFile = path.join(tmp, "db", "zapatos", "schema.d.ts")
+    const structureDir = path.join(
+      tmp,
+      "db",
+      "structure",
+      "public",
+      "tables",
+      "foo",
+    )
+
+    expect(fs.existsSync(zapatosFile)).toBe(true)
+    expect(fs.existsSync(path.join(structureDir, "table.sql"))).toBe(true)
+    expect(process.env.DATABASE_URL).toBe(
+      "postgres://postgres:postgres@127.0.0.1:1/missing",
+    )
+  } finally {
+    if (previousDatabaseUrl === undefined) delete process.env.DATABASE_URL
+    else process.env.DATABASE_URL = previousDatabaseUrl
+
+    fs.rmSync(tmp, { recursive: true, force: true })
+  }
+})
+
+test("generate with pglite restores DATABASE_URL after failure", async () => {
+  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "pgstrap-generate-"))
+  const migrationsDir = path.join(tmp, "migrations")
+  const dbDir = path.join(tmp, "db")
+  const previousDatabaseUrl = process.env.DATABASE_URL
+
+  fs.mkdirSync(migrationsDir, { recursive: true })
+  fs.writeFileSync(
+    path.join(migrationsDir, "001_create_table.js"),
+    migrationFile,
   )
+  fs.writeFileSync(dbDir, "not a directory")
+
+  process.env.DATABASE_URL = "postgres://existing:secret@localhost:5432/app"
+
+  try {
+    await expect(
+      generate({
+        schemas: ["public"],
+        defaultDatabase: "postgres",
+        dbDir,
+        migrationsDir,
+      }),
+    ).rejects.toThrow()
 
-  expect(fs.existsSync(zapatosFile)).toBe(true)
-  expect(fs.existsSync(path.join(structureDir, "table.sql"))).toBe(true)
+    expect(process.env.DATABASE_URL).toBe(
+      "postgres://existing:secret@localhost:5432/app",
+    )
+  } finally {
+    if (previousDatabaseUrl === undefined) delete process.env.DATABASE_URL
+    else process.env.DATABASE_URL = previousDatabaseUrl
 
-  fs.rmSync(tmp, { recursive: true, force: true })
+    fs.rmSync(tmp, { recursive: true, force: true })
+  }
 })