Runtime assertions for Ruby
literal.fun
ruby
Results are assumed to be successful unless a failure is thrown
Updated `Literal.Result`’s block handling to assume success for returned values. Calling `success` or `failure` on the emitter throws.
This prevents you haven’t to remember to use `next` instead of `return` whern using the block.
+60
-3
+13
-3
lib/literal.rb
+13
-3
lib/literal.rb
···
85
85
result_type = Result::Generic.new(success_type, failure_type)
86
86
87
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if block_given?
88
-
result = yield(result_type)
89
-
Literal.check(result, result_type)
90
-
result
88
+
caught = catch do |ball|
89
+
emitter = Result::Emitter.new(type: result_type, ball:)
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+
yield(emitter)
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+
end
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+
93
+
case caught
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+
when Result::Thrown
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+
Literal.check(caught.result, result_type)
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+
caught.result
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+
else
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+
Literal.check(caught, success_type)
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+
result_type.success(caught)
100
+
end
91
101
else
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102
result_type
93
103
end
+25
lib/literal/result.rb
+25
lib/literal/result.rb
···
1
1
# frozen_string_literal: true
2
2
3
3
class Literal::Result
4
+
class Thrown
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+
def initialize(result)
6
+
@result = result
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+
freeze
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+
end
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+
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+
attr_reader :result
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+
end
12
+
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+
class Emitter
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+
def initialize(type:, ball:)
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+
@type = type
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+
@ball = ball
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+
freeze
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+
end
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+
20
+
def success(value)
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+
throw(@ball, Thrown.new(@type.success(value)))
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+
end
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+
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+
def failure(error)
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+
throw(@ball, Thrown.new(@type.failure(error)))
26
+
end
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+
end
28
+
4
29
class Generic
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include Literal::Type
6
31
+22
test/result.test.rb
+22
test/result.test.rb
···
11
11
assert_equal 42, result.value!
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12
end
13
13
14
+
test "result block wraps returned success values" do
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+
result = Literal::Result(Integer, Symbol) do
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+
42
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+
end
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+
19
+
assert result.success?
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+
assert_equal 42, result.value!
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+
assert_equal Integer, result.success_type
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+
assert_equal Symbol, result.failure_type
23
+
end
24
+
25
+
test "result block checks returned values against success type" do
26
+
error = assert_raises(Literal::TypeError) do
27
+
Literal::Result(Integer, Symbol) do
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+
"42"
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+
end
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+
end
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+
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+
assert_equal Integer, error.to_h[:expected]
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+
assert_equal "42", error.to_h[:actual]
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+
end
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+
14
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test "result block must return a matching result" do
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assert_raises(Literal::TypeError) do
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Literal::Result(Integer, Symbol) do