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

44 lines
1.0 KiB
Crystal

require "./base"
module Ameba::Rule::Performance
# This rule is used to identify usage of `compact` calls that follow `map`.
#
# For example, this is considered inefficient:
#
# ```
# %w[Alice Bob].map(&.match(/^A./)).compact
# ```
#
# And can be written as this:
#
# ```
# %w[Alice Bob].compact_map(&.match(/^A./))
# ```
#
# YAML configuration example:
#
# ```
# Performance/CompactAfterMap:
# Enabled: true
# ```
class CompactAfterMap < Base
properties do
description "Identifies usage of `compact` calls that follow `map`"
end
MSG = "Use `compact_map {...}` instead of `map {...}.compact`"
def test(source)
AST::NodeVisitor.new self, source, skip: :macro
end
def test(source, node : Crystal::Call)
return unless node.name == "compact" && (obj = node.obj)
return unless obj.is_a?(Crystal::Call) && obj.block
return unless obj.name == "map"
issue_for obj.name_location, node.name_end_location, MSG
end
end
end