Class: Tryouts::ExpectationEvaluators::False

Inherits:
Base
  • Object
show all
Defined in:
lib/tryouts/expectation_evaluators/false.rb

Overview

Evaluator for boolean false expectations using syntax: #=/=> expression

PURPOSE:

  • Validates that an expression evaluates to exactly false (not falsy)
  • Provides explicit boolean validation for documentation-style tests
  • Distinguishes between true/false and truthy/falsy values

SYNTAX: #=/=> boolean_expression Examples:

[1, 2, 3]  #=/=> result.empty?            # Pass: expression is false
[1, 2, 3]  #=/=> result.include?(5)       # Pass: expression is false
[]         #=/=> result.include?(1)       # Pass: expression is false
[]         #=/=> result.empty?            # Fail: expression is true
[1, 2, 3]  #=/=> result.first             # Fail: expression is 1 (truthy but not false)
[]         #=/=> result.first             # Fail: expression is nil (falsy but not false)

BOOLEAN STRICTNESS:

  • Only passes when expression evaluates to exactly false (not falsy)
  • Fails for true, nil, 0, "", [], {}, or any non-false value
  • Uses Ruby's === comparison for exact boolean matching
  • Encourages explicit boolean expressions in documentation

IMPLEMENTATION DETAILS:

  • Expression has access to result and _ variables (actual_result)
  • Expected display shows 'false (exactly)' for clarity
  • Actual display shows the evaluated expression result
  • Distinguishes from regular expectations through strict false matching

DESIGN DECISIONS:

  • Strict false matching prevents accidental falsy value acceptance
  • Clear expected display explains the exact requirement
  • Expression evaluation provides flexible boolean logic testing
  • Part of unified #= prefix convention for all expectation types
  • Uses #=/=> syntax to visually distinguish from true expectations

Instance Attribute Summary

Attributes inherited from Base

#context, #expectation, #test_case

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from Tryouts::ExpectationEvaluators::Base

Class Method Details

.handles?(expectation_type) ⇒ Boolean

Returns:



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# File 'lib/tryouts/expectation_evaluators/false.rb', line 44

def self.handles?(expectation_type)
  expectation_type == :false # rubocop:disable Lint/BooleanSymbol
end

Instance Method Details

#evaluate(actual_result = nil) ⇒ Object 



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# File 'lib/tryouts/expectation_evaluators/false.rb', line 48

def evaluate(actual_result = nil)
  expectation_result = ExpectationResult.from_result(actual_result)
  expression_result  = eval_expectation_content(@expectation.content, expectation_result)

  build_result(
    passed: expression_result == false,
    actual: expression_result,
    expected: false,
  )
rescue StandardError => ex
  handle_evaluation_error(ex, actual_result)
end