New rule: empty ensure

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Vitalii Elenhaupt 2017-11-16 16:31:32 +02:00
parent bdf189cb7f
commit e5081fa970
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4 changed files with 120 additions and 0 deletions

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@ -10,6 +10,10 @@ DebuggerStatement:
# Disallows calls to debugger.
Enabled: true
EmptyEnsure:
# Disallows empty ensure statement.
Enabled: true
EmptyExpression:
# Disallows empty expressions.
Enabled: true

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@ -0,0 +1,68 @@
require "../../spec_helper"
module Ameba::Rule
describe EmptyEnsure do
subject = EmptyEnsure.new
it "passes if there is no empty ensure blocks" do
s = Source.new %(
def some_method
do_some_stuff
ensure
do_something_else
end
begin
do_some_stuff
ensure
do_something_else
end
def method_with_rescue
rescue
ensure
nil
end
)
subject.catch(s).should be_valid
end
it "fails if there is an empty ensure in method" do
s = Source.new %(
def method
do_some_stuff
ensure
end
)
subject.catch(s).should_not be_valid
end
it "fails if there is an empty ensure in a block" do
s = Source.new %(
begin
do_some_stuff
ensure
# nothing here
end
)
subject.catch(s).should_not be_valid
end
it "reports rule, pos and message" do
s = Source.new %(
begin
do_some_stuff
rescue
do_some_other_stuff
ensure
end
), "source.cr"
subject.catch(s).should_not be_valid
error = s.errors.first
error.rule.should_not be_nil
error.location.to_s.should eq "source.cr:3:11"
error.message.should eq "Empty `ensure` block detected"
end
end
end

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@ -12,6 +12,7 @@ module Ameba::AST
ClassVar,
Def,
EnumDef,
ExceptionHandler,
If,
InstanceVar,
LibDef,

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@ -0,0 +1,47 @@
module Ameba::Rule
# A rule that disallows empty ensure statement.
#
# For example, this is considered invalid:
#
# ```
# def some_method
# do_some_stuff
# ensure
# end
#
# begin
# do_some_stuff
# ensure
# end
# ```
#
# And it should be written as this:
#
#
# ```
# def some_method
# do_some_stuff
# ensure
# do_something_else
# end
#
# begin
# do_some_stuff
# ensure
# do_something_else
# end
# ```
#
struct EmptyEnsure < Base
def test(source)
AST::Visitor.new self, source
end
def test(source, node : Crystal::ExceptionHandler)
node_ensure = node.ensure
return if node_ensure.nil? || !node_ensure.nop?
source.error self, node.location, "Empty `ensure` block detected"
end
end
end