Skip to main content

Glue Code & Package Structure

Glue code tells Cucumber where to find step definitions, hooks, and supporting classes. Incorrect glue configuration is one of the most common causes of execution failures in Cucumber projects.

This section explains what glue really is and how to structure packages cleanly.

What is Glue in Cucumber?​

glue is a configuration that:

  • Points Cucumber to step definition packages
  • Helps Cucumber locate hooks
  • Connects feature files to executable code

Without correct glue:

Scenarios run but steps remain undefined.

Where Glue is Defined​

Glue is defined in:

  • Runner class (@CucumberOptions)
  • Test framework integration (TestNG / JUnit)

Conceptually:

Feature File → Glue → Step Definitions

What Belongs in Glue Packages​

Glue packages typically contain:

  • Step definition classes
  • Hooks classes
  • Shared context classes

They should NOT contain:

  • Page Objects
  • Utility classes
  • Test runners

Clean structure example:

src/test/java
 └── steps
     ├── login
     ├── payment
     └── common
 └── hooks
 └── runners
 └── pages
 └── utils

Glue should point only to:

steps, hooks

Feature Files Location​

Best practice:

src/test/resources/features

Feature files:

  • Should not be under Java packages
  • Should be cleanly organized by module

Multiple Glue Packages​

Glue can accept:

  • One package
  • Multiple packages

Example concept:

glue = {"steps.login", "steps.common", "hooks"}

Common Glue Issues ❌​

  • Wrong package name
  • Step classes outside glue path
  • Typo in glue configuration
  • Multiple step definitions for same step

These cause:

  • Undefined steps
  • Duplicate step errors

How to Debug Glue Issues​

  • Check package names carefully
  • Use dry run
  • Verify step definition annotations
  • Avoid overlapping glue paths

Best Practices​

  • Keep glue minimal
  • Separate steps by domain
  • Avoid deep package nesting
  • Keep naming consistent

Interview-Ready Questions​

Q: What is glue in Cucumber?
A: It tells Cucumber where to find step definitions and hooks.

Q: What happens if glue is misconfigured?
A: Steps remain undefined.

Key Takeaways​

  • Glue connects feature files to code
  • Only steps and hooks belong in glue
  • Clean package structure prevents errors
  • Most undefined-step issues are glue-related