shard-ameba/src/ameba/rule/performance/minmax_after_map.cr

68 lines
1.9 KiB
Crystal

require "./base"
module Ameba::Rule::Performance
# This rule is used to identify usage of `min/max/minmax` calls that follow `map`.
#
# For example, this is considered invalid:
#
# ```
# %w[Alice Bob].map(&.size).min
# %w[Alice Bob].map(&.size).max
# %w[Alice Bob].map(&.size).minmax
# ```
#
# And it should be written as this:
#
# ```
# %w[Alice Bob].min_of(&.size)
# %w[Alice Bob].max_of(&.size)
# %w[Alice Bob].minmax_of(&.size)
# ```
#
# YAML configuration example:
#
# ```
# Performance/MinMaxAfterMap:
# Enabled: true
# ```
class MinMaxAfterMap < Base
properties do
description "Identifies usage of `min/max/minmax` calls that follow `map`"
end
MSG = "Use `%s {...}` instead of `map {...}.%s`."
CALL_NAMES = %w[min min? max max? minmax minmax?]
def test(source)
AST::NodeVisitor.new self, source, skip: :macro
end
def test(source, node : Crystal::Call)
return unless node.name.in?(CALL_NAMES) && node.block.nil? && node.args.empty?
return unless (obj = node.obj) && obj.is_a?(Crystal::Call)
return unless obj.name == "map" && obj.block && obj.args.empty?
return unless name_location = obj.name_location
return unless end_location = node.name_end_location
of_name = node.name.sub(/(.+?)(\?)?$/, "\\1_of\\2")
message = MSG % {of_name, node.name}
issue_for name_location, end_location, message do |corrector|
next unless node_name_location = node.name_location
# TODO: switching the order of the below calls breaks the corrector
corrector.replace(
name_location,
name_location.adjust(column_number: {{ "map".size - 1 }}),
of_name
)
corrector.remove(
node_name_location.adjust(column_number: -1),
end_location
)
end
end
end
end