added pg_visibility contrib extension

Author: tdrz

docs/extensions/extensions.data.ts

@@ -254,13 +254,28 @@ const baseExtensions: Extension[] = [
       only as a last resort.
     `,
     shortDescription: 'Perform low-level surgery on relation data',
-    docs: 'https://www.postgresql.org/docs/18/dict-int.html',
+    docs: 'https://www.postgresql.org/docs/current/pgsurgery.html',
     tags: ['postgres extension', 'postgres/contrib'],
     importPath: '@electric-sql/pglite/contrib/pg_surgery',
     importName: 'pg_surgery',
     core: true,
     size: 2635,
   },
+  {
+    name: 'pg_visibility',
+    description: `
+      The pg_visibility module provides a means for examining the visibility map (VM) 
+      and page-level visibility information of a table. It also provides functions to 
+      check the integrity of a visibility map and to force it to be rebuilt.
+    `,
+    shortDescription: 'Visibility map information and utilities',
+    docs: 'https://www.postgresql.org/docs/current/pgvisibility.html',
+    tags: ['postgres extension', 'postgres/contrib'],
+    importPath: '@electric-sql/pglite/contrib/pg_visibility',
+    importName: 'pg_visibility',
+    core: true,
+    size: 4159,
+  },
   {
     name: 'pg_freespacemap',
     description: `

docs/repl/allExtensions.ts

@@ -20,6 +20,7 @@ export { pg_buffercache } from '@electric-sql/pglite/contrib/pg_buffercache'
 export { pg_freespacemap } from '@electric-sql/pglite/contrib/pg_freespacemap'
 export { pg_surgery } from '@electric-sql/pglite/contrib/pg_surgery'
 export { pg_trgm } from '@electric-sql/pglite/contrib/pg_trgm'
+export { pg_visibility } from '@electric-sql/pglite/contrib/pg_visibility'
 export { seg } from '@electric-sql/pglite/contrib/seg'
 export { tablefunc } from '@electric-sql/pglite/contrib/tablefunc'
 export { tcn } from '@electric-sql/pglite/contrib/tcn'

packages/pglite/src/contrib/pg_visibility.ts

@@ -0,0 +1,16 @@
+import type {
+  Extension,
+  ExtensionSetupResult,
+  PGliteInterface,
+} from '../interface'
+
+const setup = async (_pg: PGliteInterface, _emscriptenOpts: any) => {
+  return {
+    bundlePath: new URL('../../release/pg_visibility.tar.gz', import.meta.url),
+  } satisfies ExtensionSetupResult
+}
+
+export const pg_visibility = {
+  name: 'pg_visibility',
+  setup,
+} satisfies Extension

packages/pglite/tests/contrib/pg_visibility.test.js

@@ -0,0 +1,65 @@
+import { it, expect } from 'vitest'
+import { PGlite } from '../../dist/index.js'
+import { pg_visibility } from '../../dist/contrib/pg_visibility.js'
+
+it('pg_visibility', async () => {
+  const pg = await PGlite.create({
+    extensions: {
+      pg_visibility,
+    },
+  })
+
+  await pg.exec('CREATE EXTENSION IF NOT EXISTS pg_visibility;')
+
+  await pg.exec(`
+CREATE TABLE IF NOT EXISTS test (
+id SERIAL PRIMARY KEY,
+name TEXT
+);
+`)
+
+  await pg.exec(`
+INSERT INTO test (name) VALUES ('test');
+UPDATE test SET name = 'test2';
+SELECT * FROM test;
+`)
+
+  const visible = await pg.query(`
+-- Show all invisible tuples in a specific table using pg_visibility
+SELECT * 
+FROM pg_visibility('test') 
+WHERE all_visible = false;
+`)
+
+  expect(visible.rows).toEqual([
+    {
+      blkno: 0,
+      all_visible: false,
+      all_frozen: false,
+      pd_all_visible: false,
+    },
+  ])
+
+  const visibilityMap = await pg.query(`
+-- Check visibility map status for a table
+SELECT * 
+FROM pg_visibility_map('test');
+`)
+
+  expect(visibilityMap.rows).toEqual([
+    {
+      blkno: 0,
+      all_visible: false,
+      all_frozen: false,
+    },
+  ])
+
+  const frozen = await pg.query(`
+-- Find pages with all-frozen tuples
+SELECT * 
+FROM pg_visibility('test')
+WHERE all_frozen = true;
+`)
+
+  expect(frozen.rows).toEqual([])
+})