Merge pull request #293 from crystal-ameba/Sija/refactor-static-comparison-rule

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Sijawusz Pur Rahnama 2022-11-02 10:10:52 +01:00 committed by GitHub
commit 816c8b11cd
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2 changed files with 36 additions and 12 deletions

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@ -1,9 +1,9 @@
require "../../../spec_helper"
module Ameba::Rule::Lint
subject = StaticComparison.new
subject = LiteralsComparison.new
describe StaticComparison do
describe LiteralsComparison do
it "passes for valid cases" do
expect_no_issues subject, <<-CRYSTAL
"foo" == foo
@ -13,6 +13,13 @@ module Ameba::Rule::Lint
CRYSTAL
end
it "reports if there is a regex comparison possibly evaluating to the same" do
expect_issue subject, <<-CRYSTAL
/foo/ === "foo"
# ^^^^^^^^^^^^^ error: Comparison most likely evaluates to the same
CRYSTAL
end
it "reports if there is a static comparison evaluating to the same" do
expect_issue subject, <<-CRYSTAL
"foo" === "foo"

View file

@ -1,6 +1,9 @@
module Ameba::Rule::Lint
# This rule is used to identify static comparisons -
# the ones that will always have the same result.
# This rule is used to identify comparisons between two literals.
#
# They usually have the same result - except for non-primitive
# types like containers, range or regex.
#
#
# For example, this will be always false:
#
@ -11,39 +14,53 @@ module Ameba::Rule::Lint
# YAML configuration example:
#
# ```
# Lint/StaticComparison:
# Lint/LiteralsComparison:
# Enabled: true
# ```
class StaticComparison < Base
class LiteralsComparison < Base
include AST::Util
properties do
description "Identifies static comparisons"
description "Identifies comparisons between literals"
end
OP_NAMES = %w(=== == !=)
MSG = "Comparison always evaluates to %s"
PRIMITIVES = {
MSG = "Comparison always evaluates to %s"
MSG_LIKELY = "Comparison most likely evaluates to %s"
PRIMITIVE_LITERAL_TYPES = {
Crystal::NilLiteral,
Crystal::BoolLiteral,
Crystal::NumberLiteral,
Crystal::CharLiteral,
Crystal::StringLiteral,
Crystal::SymbolLiteral,
Crystal::ProcLiteral,
Crystal::Path,
}
DYNAMIC_LITERAL_TYPES = {
Crystal::RangeLiteral,
Crystal::RegexLiteral,
Crystal::TupleLiteral,
Crystal::NamedTupleLiteral,
Crystal::ArrayLiteral,
Crystal::HashLiteral,
Crystal::ProcLiteral,
}
LITERAL_TYPES =
PRIMITIVE_LITERAL_TYPES + DYNAMIC_LITERAL_TYPES
def test(source, node : Crystal::Call)
return unless node.name.in?(OP_NAMES)
return unless (obj = node.obj) && (arg = node.args.first?)
return unless obj.class.in?(PRIMITIVES) && arg.class.in?(PRIMITIVES)
return unless obj.class.in?(LITERAL_TYPES) &&
arg.class.in?(LITERAL_TYPES)
is_dynamic = obj.class.in?(DYNAMIC_LITERAL_TYPES) ||
arg.class.in?(DYNAMIC_LITERAL_TYPES)
what =
case node.name
@ -52,7 +69,7 @@ module Ameba::Rule::Lint
when "!=" then (obj.to_s != arg.to_s).to_s
end
issue_for node, MSG % what
issue_for node, (is_dynamic ? MSG_LIKELY : MSG) % what
end
end
end