From 56c6f0004ac2dd6465633d1e03d9d3ea2c037e69 Mon Sep 17 00:00:00 2001
From: DavertMik <davert@testomat.io>
Date: Sat, 20 Jun 2026 01:20:41 +0300
Subject: [PATCH] fix(data): detect DataTable structurally so Data() works
 under tsx/cjs (#5641)

`Data(table)` threw "Invalid data type" for a valid DataTable when the test
file is loaded via `require: ['tsx/cjs']`. tsx transpiles the test to CommonJS
and gives it its own copy of the `DataTable` class, while the framework runs as
ESM with a different copy, so the `instanceof DataTable` check fails for a
genuine DataTable.

Detect a DataTable by its structure (`array`/`rows` arrays + `add` method) in
addition to `instanceof`, which survives duplicate module instances. Plain
arrays, generators and functions still fall through to their own branches.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 lib/data/context.js       |  7 ++++++-
 test/unit/data/ui_test.js | 24 ++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/lib/data/context.js b/lib/data/context.js
index c2e0bc2e4..01b9c6403 100644
--- a/lib/data/context.js
+++ b/lib/data/context.js
@@ -82,8 +82,13 @@ function isTableDataRow(row) {
   return has.call(row, 'data') && has.call(row, 'skip')
 }
 
+function isDataTable(dataTable) {
+  if (dataTable instanceof DataTable) return true
+  return Boolean(dataTable) && Array.isArray(dataTable.array) && Array.isArray(dataTable.rows) && typeof dataTable.add === 'function'
+}
+
 function detectDataType(dataTable) {
-  if (dataTable instanceof DataTable) {
+  if (isDataTable(dataTable)) {
     return dataTable.rows
   }
 
diff --git a/test/unit/data/ui_test.js b/test/unit/data/ui_test.js
index abe871734..8cfa7b730 100644
--- a/test/unit/data/ui_test.js
+++ b/test/unit/data/ui_test.js
@@ -97,5 +97,29 @@ describe('ui', () => {
       const dataScenarioConfig = context.Data(dataTable).Scenario('scenario', () => {})
       expect('scenario | {"username":"Username","password":"*****"}').to.equal(dataScenarioConfig.scenarios[2].test.title)
     })
+
+    it('accepts a DataTable coming from a duplicate module instance', () => {
+      class ForeignDataTable {
+        constructor(array) {
+          this.array = array
+          this.rows = []
+        }
+
+        add(array) {
+          const data = {}
+          this.array.forEach((key, i) => (data[key] = array[i]))
+          this.rows.push({ skip: false, data })
+        }
+      }
+
+      const foreign = new ForeignDataTable(['username', 'password'])
+      foreign.add(['jon', 'snow'])
+      foreign.add(['tyrion', 'lannister'])
+
+      expect(foreign).to.not.be.instanceOf(DataTable)
+      const dataScenarioConfig = context.Data(foreign).Scenario('scenario', () => {})
+      expect(dataScenarioConfig.scenarios).to.have.lengthOf(2)
+      expect(dataScenarioConfig.scenarios[0].test.title).to.equal('scenario | {"username":"jon","password":"snow"}')
+    })
   })
 })