Correctness Rules (BC001–BC010)

July 3, 2026 · View on GitHub

Rules that detect definitively wrong structures causing runtime errors or test failures.

Default severity: ERROR

BC001: duplicate-scenario-names

Detects scenarios (including scenario outlines) that share the same name within a single feature file. Duplicate names cause ambiguity in test execution and reporting.

Tags: scenarios, naming

Since: 0.5.0

Example

??? example "Before → After"

**Before:**

```gherkin
Feature: Login

  Scenario: Successful login
    Given a user

  Scenario: Successful login
    Given an admin
```

**After:**

```gherkin
Feature: Login

  Scenario: Successful user login
    Given a user

  Scenario: Successful admin login
    Given an admin
```

BC002: empty-feature

Detects feature files that contain no scenarios or scenario outlines. An empty feature file may indicate an incomplete or abandoned feature.

Tags: feature, completeness

Since: 0.5.0

Example

??? example "Before → After"

**Before:**

```gherkin
Feature: User Profile
```

**After:**

```gherkin
Feature: User Profile

  Scenario: View profile
    Given a logged-in user
    When I navigate to the profile page
    Then I see my profile information
```

BC003: scenario-outline-without-examples

Detects Scenario Outlines that lack at least one Examples table. A Scenario Outline without Examples cannot execute.

Tags: scenario-outline, examples

Since: 0.5.0

Example

??? example "Before → After"

**Before:**

```gherkin
Feature: Login

  Scenario Outline: Successful login
    Given a user with username <username>
    When I log in
    Then I see the dashboard
```

**After:**

```gherkin
Feature: Login

  Scenario Outline: Successful login
    Given a user with username <username>
    When I log in
    Then I see the dashboard

    Examples:
      | username |
      | alice    |
      | bob      |
```

BC004: invalid-tag-syntax

Detects tags that do not follow the valid syntax: @ followed by alphanumeric characters and underscores.

Tags: tags, syntax

Since: 0.5.0

Auto-fix: Safe — replaces invalid characters with _.

Example

??? example "Before → After"

**Before:**

```gherkin
@smoke-test
Feature: Login
```

**After:**

```gherkin
@smoke_test
Feature: Login
```

BC005: duplicate-feature-names

Detects feature files that share the same feature name. Duplicate feature names cause confusion in test reports.

Tags: feature, naming, cross-file

Scope: Cross-file

Since: 0.5.0

Example

??? example "Before → After"

**Before** (`features/login.feature`):

```gherkin
Feature: Authentication
```

**Before** (`features/signup.feature`):

```gherkin
Feature: Authentication
```

**After** (`features/login.feature`):

```gherkin
Feature: User Login
```

**After** (`features/signup.feature`):

```gherkin
Feature: User Registration
```

BC006: invalid-example-table

Detects Examples tables with empty headers, no data rows, or mismatched column counts between headers and data rows.

Tags: examples, table, syntax

Since: 0.5.0

Example

??? example "Before → After"

**Before:**

```gherkin
  Scenario Outline: Login
    Given a user with <username> and <password>

    Examples:
      | username | password |
      | alice    |
      | bob      | secret   | extra |
```

**After:**

```gherkin
  Scenario Outline: Login
    Given a user with <username> and <password>

    Examples:
      | username | password |
      | alice    | pass123  |
      | bob      | secret   |
```

BC007: empty-scenario

Detects scenarios that contain no steps. An empty scenario provides no test coverage and may indicate an incomplete or placeholder scenario.

Tags: scenarios, completeness

Since: 1.2.0

Example

??? example "Before → After"

**Before:**

```gherkin
Feature: Test

  Scenario: Empty scenario

  Scenario: Real scenario
    Given a step
```

**After:**

```gherkin
Feature: Test

  Scenario: Real scenario
    Given a step
```

BC008: unused-outline-placeholder

Detects columns in Examples tables that are never referenced via <param> placeholders in the scenario outline steps. Unused columns add noise to the data.

Tags: scenario-outline, examples, placeholders

Since: 1.2.0

BC009: undefined-outline-placeholder

Detects <param> placeholders in scenario outline steps that are not defined in any Examples table header. Undefined placeholders cause runtime errors in behave.

Tags: scenario-outline, examples, placeholders

Since: 1.2.0

BC010: duplicate-examples-name

Detects Examples blocks that share the same name within a single scenario outline. Duplicate names cause confusion in test reports.

Tags: examples, naming, scenario-outline

Since: 1.2.0