Tag Expressions

BehaveX supports two types of tag expressions for filtering test scenarios.

Tag Expressions v1 (Legacy Format)

Tag Expressions v1 use a simple syntax compatible with all Behave versions:

# Run scenarios with a specific tag
behavex -t=@smoke

# Exclude scenarios with a tag
behavex -t=~@slow

# Multiple conditions (AND logic)
behavex -t=@smoke -t=~@slow

# Multiple tags (OR logic)
behavex -t=@smoke,@regression

Advanced v1 examples:

# Smoke tests excluding slow ones
behavex -t=@smoke -t=~@slow

# Regression or integration tests
behavex -t=@regression,@integration

# Critical tests excluding known issues
behavex -t=@critical -t=~@known_issue

# Multiple exclusions
behavex -t=@api -t=~@slow -t=~@flaky

Tag Expressions v2 (Cucumber Style)

Note: Tag Expressions v2 require Behave 1.3.0 or newer. BehaveX automatically detects v2 syntax and uses Behave’s native parser.

Boolean Operators

# AND logic
behavex -t="@smoke and @api"

# OR logic
behavex -t="@smoke or @regression"

# NOT logic
behavex -t="not @slow"

# Combinations
behavex -t="@smoke and not @slow"

Parentheses Grouping

behavex -t="(@smoke or @regression) and not @slow"
behavex -t="(@smoke and @api) or (@regression and @ui)"
behavex -t="(((@smoke or @regression) and @api) or @critical) and not @slow"

Wildcard Matching

# Prefix matching
behavex -t="@smoke*"        # Matches @smoke, @smoke_test, @smoke_api

# Suffix matching
behavex -t="@*_test"        # Matches @api_test, @ui_test, @smoke_test

# Substring matching
behavex -t="@*smoke*"       # Matches @smoke, @smoke_test, @test_smoke

# Wildcard combinations
behavex -t="@smoke* and not @*_slow"
behavex -t="@*_api or @*_ui"

Advanced v2 Examples

# Production-ready filtering
behavex -t="(@smoke or @regression) and not (@slow or @flaky)"

# Environment-specific
behavex -t="@api and (@staging or @production) and not @experimental"

# Feature-based with wildcards
behavex -t="@user* and (@*_positive or @*_critical) and not @*_slow"

# Complex business logic
behavex -t="((@smoke and @high_priority) or @critical) and not (@known_issue or @skip)"

Multiple `-t` Arguments

Multiple -t arguments are combined with AND logic:

behavex -t="@smoke or @regression" -t="not @slow"
# Equivalent to: (@smoke or @regression) and (not @slow)

Version Compatibility

Feature	Behave 1.2.6	Behave 1.3.0+
Tag Expressions v1	✅ Full Support	✅ Full Support
Tag Expressions v2	❌ Not Supported	✅ Full Support
Boolean operators (and, or, not)	❌	✅
Parentheses grouping	❌	✅
Wildcard matching	❌	✅

Migration from v1 to v2

# v1 Format                              v2 Equivalent
behavex -t=@smoke -t=~@slow          →  behavex -t="@smoke and not @slow"
behavex -t=@smoke,@regression        →  behavex -t="@smoke or @regression"
behavex -t=@api -t=~@slow -t=~@flaky →  behavex -t="@api and not @slow and not @flaky"

Best Practices

Use quotes around v2 expressions to prevent shell interpretation
Test expressions with --dry-run to verify scenario selection before running
Prefer v2 syntax for better readability when using Behave 1.3.0+
Use wildcards to reduce maintenance when tag naming follows patterns
Group complex logic with parentheses for clarity