Cucumber Attachment Issue: Hooks Dumped At End Of Scenarios
Have you ever found yourself sifting through your Cucumber reports, trying to match up screenshots or other attached files with the exact step they belong to? If you've recently upgraded to Cucumber 10.1, you might be experiencing a frustrating change: attachments from hooks, like AfterStep, are now appearing at the very end of your scenarios, completely losing their context. This article dives deep into this issue, explaining what's happening, why it's a problem, and how it deviates from previous versions and expected behavior.
The Problem with Context Loss
When you upgrade to Cucumber 10.1 and use an external formatter like html-formatter, you might notice that the attachments generated by your hooks are no longer displayed alongside the steps they were associated with. Instead, they are all collected and presented at the end of the entire scenario. This is a significant departure from how the native html formatter worked in earlier versions of Cucumber. In those older versions, attachments were seamlessly integrated, appearing right before or after the specific step where they were generated. This contextual placement was incredibly helpful for debugging and understanding test failures. Now, with attachments dumped at the end, you lose that immediate visual link, making it much harder to pinpoint the cause of an issue. Imagine a scenario with multiple steps, each generating a screenshot. If all those screenshots are lumped together at the end, you have to manually correlate them with the sequence of events, which can be a time-consuming and error-prone process. This isn't just an aesthetic change; it's a functional regression that impacts the usability of your test reports.
What's Actually Happening?
The core of the issue lies in how Cucumber 10.1, in conjunction with the html-formatter, processes and outputs attachments. The new architecture seems to be collecting all attachments generated within a scenario's hooks and outputting them in a batch at the conclusion of the scenario's execution. This differs from the previous behavior where attachments were often associated more directly with the specific step or hook that generated them, allowing formatters to place them appropriately within the report's flow. The provided JSON and message outputs, even after redaction, hint at this structural change in how attachment data is being structured and passed along. The html-formatter then simply renders this data as it receives it, leading to the observed behavior of attachments appearing at the end. It's possible that the internal messaging or event handling for attachments has changed, leading to this shift in output order. When you attach a screenshot in an AfterStep hook, for example, the expectation is that this attachment should be visually tied to the step that just executed. However, in the current setup, this link is broken. The report generator receives the attachment information but associates it with the end of the scenario block rather than the specific step. This makes the reports less intuitive and significantly hinders the debugging process, as the visual evidence is no longer presented in its immediate chronological context.
The Expected Behavior: Context is Key
What we expect to see is a report where attachments are logically placed. For instance, if an AfterStep hook captures a screenshot, that screenshot should appear immediately after the step that just ran. This allows testers and developers to quickly scan the report and see the state of the application at critical points. The old Cucumber HTML report, as demonstrated, clearly shows this expected behavior. Each attachment is presented in close proximity to the step that triggered its creation. This intuitive layout makes it easy to follow the flow of the test and identify exactly what happened when a failure occurred. The react-components demo, while having its own quirks like collapsible hooks, at least attempts to show attachments where they were made, further reinforcing the idea that contextual placement is the desired outcome. The difference is stark: instead of a clear, step-by-step visual narrative, we're getting a collection of evidence dumped at the end, requiring extra effort to piece together. This isn't just about pretty reports; it's about efficient debugging. When a test fails, the most crucial information is often a visual snapshot of the application's state at that moment. Losing this direct connection between the step and its attachment makes the debugging process significantly more laborious and less effective. We want to see the screenshot of the login page right after the step that attempted to log in, not twenty steps later at the end of the scenario.
Versions and Reproduction Steps
This issue seems to have emerged with the upgrade to Cucumber 10.1.1. The user reported that previous versions, specifically Cucumber 3.2.0, handled attachments correctly. Here's a breakdown of the versions involved:
-
Affected Versions:
cucumber(10.1.1)cucumber-ci-environment(10.0.1)cucumber-core(15.3.0)cucumber-cucumber-expressions(18.0.1)cucumber-gherkin(34.0.0)cucumber-html-formatter(21.15.1)cucumber-messages(27.2.0)cucumber-tag-expressions(8.0.0)- Ruby MRI 3.4.2
-
Working Versions:
cucumber(3.2.0)cucumber-core(3.2.1)cucumber-expressions(6.0.1)cucumber-tag_expressions(1.1.1)cucumber-wire(0.0.1)gherkin(5.1.0)- Ruby MRI 3.4.2
How to Reproduce the Issue
Reproducing this problem is straightforward and involves a simple feature file, step definition, and hook setup. The provided example clearly illustrates the problematic behavior:
test.feature:
Feature: Attachments in Cucumber Reports
Scenario: Attaching attachments in multiple steps in a Scenario
Given I open a web browser
When I go to the "about:license" page
And I go to the "about:logo" page
Then I go to the "about:robots" page
step_definitions/test.rb:
Given(/^I open a web browser$/) do
# code to open a browser (placeholder)
end
When(/^I go to the "(.+)" page$/) do |page|
# code to navigate to a page (placeholder)
end
support/env.rb:
AfterStep do |scenario|
# Assuming @browser is initialized elsewhere and can save screenshots
screenshot = @browser.save_screenshot
attach(screenshot, 'image/png')
end
After do |scenario|
# This hook also attempts to attach a screenshot
screenshot = @browser.save_screenshot
attach(screenshot, 'image/png')
end
In this setup, the AfterStep hook is designed to capture a screenshot after each step and attach it to the report. Additionally, the After hook is set to capture a screenshot after the entire scenario. When you run this feature with Cucumber 10.1.1 and html-formatter, you'll observe that all these screenshots are bundled together and displayed at the end of the scenario, rather than being associated with the specific steps or the scenario's conclusion as they were in older versions.
Deeper Issues: Scenario Outlines and More
The problem becomes even more pronounced when dealing with Scenario Outlines. In older versions, attachments for each example row in a Scenario Outline were typically grouped with that specific example. However, with the current behavior, all attachments from all examples within a Scenario Outline are lumped together into one giant block at the end. This makes it incredibly difficult, if not impossible, to discern which attachment belongs to which specific test case execution. The visual context is completely lost, turning a potentially useful debugging tool into a confusing mess. This is a critical usability flaw, especially for test suites that rely heavily on Scenario Outlines to test various data combinations. The react-components demo for Scenario Outlines, while still showing some limitations like collapsed hooks, at least attempts to associate attachments with their respective examples. The current implementation in Cucumber 10.1.1, however, fails to provide this level of detail, making it challenging to diagnose failures in complex, data-driven scenarios.
Why This Matters for Debugging
Effective debugging hinges on having timely and relevant information. When a test fails, the ability to instantly see the state of the application at the moment of failure is invaluable. Attachments, such as screenshots, logs, or even DOM dumps, serve as crucial pieces of evidence. By dumping all attachments at the end of a scenario, Cucumber 10.1.1 breaks this critical link. Testers and developers are forced to manually re-trace the steps, attempting to match the evidence with the actions taken. This significantly increases the time and effort required to identify and fix bugs. In a fast-paced development environment, such delays can be costly. The original behavior of associating attachments directly with the steps or hooks that generated them provided a clear, chronological narrative. This narrative is essential for understanding not just what went wrong, but why it went wrong. The current implementation sacrifices this clarity for a consolidated, albeit less useful, output.
Conclusion: Restoring Contextual Attachments
The shift in how attachments are handled in Cucumber 10.1.1, particularly when using formatters like html-formatter, presents a significant challenge for effective test reporting and debugging. The displacement of attachments from their originating steps and hooks into a consolidated block at the end of scenarios strips away valuable context, making it harder to quickly identify the cause of test failures. This issue is amplified in Scenario Outlines, where attachments from multiple examples become indistinguishable. While the intention behind architectural changes might be to streamline processing, the practical impact on user experience and debugging efficiency is negative. We hope that future updates to Cucumber and its formatters will address this by restoring the ability to associate attachments contextually, ensuring that the valuable information they provide remains easily accessible and directly linked to the relevant parts of the test execution. Until then, users may need to explore workarounds or revert to older versions if contextual attachments are critical to their workflow.
For further insights into Cucumber's capabilities and potential solutions, you might find the official Cucumber.js documentation and the Cucumber-Ruby GitHub repository helpful resources.
