fix(pg-native): report a missing row count or command as null

packages/pg-native/lib/build-result.js

@@ -14,8 +14,11 @@ class Result {
   }
 
   consumeCommand(pq) {
-    this.command = pq.cmdStatus().split(' ')[0]
-    this.rowCount = parseInt(pq.cmdTuples(), 10)
+    // null when there is none, as pg reports it: BEGIN has no row count, an empty query no command
+    const status = pq.cmdStatus()
+    this.command = status ? status.split(' ')[0] : null
+    const tuples = pq.cmdTuples()
+    this.rowCount = tuples ? parseInt(tuples, 10) : null
   }
 
   consumeFields(pq) {

packages/pg-native/test/empty-query.js

@@ -13,4 +13,22 @@ describe('empty query', () => {
       client.end(done)
     })
   })
+
+  // what pg reports too: a command without a row count and an empty query without a command
+  // are null, not NaN and an empty string
+  it('reports no row count and no command as null', (done) => {
+    const client = new Client()
+    client.connectSync()
+    client.query('BEGIN', (err, rows, res) => {
+      assert(!err)
+      assert.strictEqual(res.command, 'BEGIN')
+      assert.strictEqual(res.rowCount, null)
+      client.query('', (err, rows, res) => {
+        assert(!err)
+        assert.strictEqual(res.command, null)
+        assert.strictEqual(res.rowCount, null)
+        client.end(done)
+      })
+    })
+  })
 })