Add Lint/NotNil rule

This commit is contained in:
Sijawusz Pur Rahnama 2022-10-30 18:14:11 +01:00
parent 09aea3da32
commit 67356f246b
2 changed files with 99 additions and 0 deletions

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require "../../../spec_helper"
module Ameba::Rule::Lint
subject = NotNil.new
describe NotNil do
it "passes for valid cases" do
expect_no_issues subject, <<-CRYSTAL
(1..3).first?.not_nil!(:foo)
not_nil!
CRYSTAL
end
it "reports if there is a `not_nil!` call" do
expect_issue subject, <<-CRYSTAL
(1..3).first?.not_nil!
# ^^^^^^^^ error: Avoid using `not_nil!`
CRYSTAL
end
context "macro" do
it "doesn't report in macro scope" do
expect_no_issues subject, <<-CRYSTAL
{{ [1, 2, 3].first.not_nil! }}
CRYSTAL
end
end
it "reports rule, pos and message" do
s = Source.new %(
(1..3).first?.not_nil!
), "source.cr"
subject.catch(s).should_not be_valid
issue = s.issues.first
issue.rule.should_not be_nil
issue.location.to_s.should eq "source.cr:1:15"
issue.end_location.to_s.should eq "source.cr:1:22"
issue.message.should eq "Avoid using `not_nil!`"
end
end
end

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module Ameba::Rule::Lint
# This rule is used to identify usages of `not_nil!` calls.
#
# For example, this is considered a code smell:
#
# ```
# names = %w[Alice Bob]
# alice = names.find { |name| name == "Alice" }.not_nil!
# ```
#
# And can be written as this:
#
# ```
# names = %w[Alice Bob]
# alice = names.find { |name| name == "Alice" }
#
# if alice
# # ...
# end
# ```
#
# YAML configuration example:
#
# ```
# Lint/NotNil:
# Enabled: true
# ```
class NotNil < Base
include AST::Util
properties do
description "Identifies usage of `not_nil!` calls"
end
NOT_NIL_NAME = "not_nil!"
MSG = "Avoid using `not_nil!`"
def test(source)
AST::NodeVisitor.new self, source, skip: [
Crystal::Macro,
Crystal::MacroExpression,
Crystal::MacroIf,
Crystal::MacroFor,
]
end
def test(source, node : Crystal::Call)
return unless node.name == NOT_NIL_NAME
return unless node.obj && node.args.empty?
return unless name_location = node.name_location
return unless end_location = name_end_location(node)
issue_for name_location, end_location, MSG
end
end
end