fix(pg): use a Buffer when parsing binary

The call to parseArray was not working as expected because the value was
being sent as a string instead of a Buffer. The binary parsers in
pg-types all assume the incoming value is a Buffer.

Author: hjr3

packages/pg/lib/result.js

@@ -66,7 +66,8 @@ class Result {
       const rawValue = rowData[i]
       const field = this.fields[i].name
       if (rawValue !== null) {
-        row[field] = this._parsers[i](rawValue)
+        const v = this.fields[i].format === 'binary' ? Buffer.from(rawValue) : rawValue
+        row[field] = this._parsers[i](v)
       } else {
         row[field] = null
       }

packages/pg/test/integration/gh-issues/3487-tests.js

@@ -0,0 +1,25 @@
+const helper = require('../test-helper')
+const assert = require('assert')
+
+const suite = new helper.Suite()
+
+suite.testAsync('allows you to switch between format modes for arrays', async () => {
+  const client = new helper.pg.Client()
+  await client.connect()
+
+  const r1 = await client.query({
+    text: 'SELECT CAST($1 AS INT[]) as a',
+    values: [[1, 2, 8]],
+    binary: false,
+  })
+  assert.deepEqual([1, 2, 8], r1.rows[0].a)
+
+  const r2 = await client.query({
+    text: 'SELECT CAST($1 AS INT[]) as a',
+    values: [[4, 5, 6]],
+    binary: true,
+  })
+  assert.deepEqual([4, 5, 6], r2.rows[0].a)
+
+  await client.end()
+})