Merge pull request #201 from crystal-ameba/feature/verbose-block-rule

Add Style/VerboseBlock rule
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Sijawusz Pur Rahnama 2021-02-08 15:13:01 +01:00 committed by GitHub
commit a169b12b99
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7 changed files with 444 additions and 8 deletions

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@ -120,7 +120,7 @@ module Ameba
it "returns list of sources" do
config.sources.size.should be > 0
config.sources.first.should be_a Source
config.sources.any? { |s| s.fullpath == __FILE__ }.should be_true
config.sources.any?(&.fullpath.==(__FILE__)).should be_true
end
it "returns a list of sources mathing globs" do
@ -130,7 +130,7 @@ module Ameba
it "returns a lisf of sources excluding 'Excluded'" do
config.excluded = %w(**/config_spec.cr)
config.sources.any? { |s| s.fullpath == __FILE__ }.should be_false
config.sources.any?(&.fullpath.==(__FILE__)).should be_false
end
end

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@ -0,0 +1,214 @@
require "../../../spec_helper"
module Ameba::Rule::Style
subject = VerboseBlock.new
describe VerboseBlock do
it "passes if there is no potential performance improvements" do
source = Source.new %(
(1..3).any?(&.odd?)
(1..3).join('.', &.to_s)
(1..3).each_with_index { |i, idx| i * idx }
(1..3).map { |i| typeof(i) }
(1..3).map { |i| i || 0 }
(1..3).map { |i| :foo }
(1..3).map { |i| :foo.to_s.split.join('.') }
(1..3).map { :foo }
)
subject.catch(source).should be_valid
end
it "passes if the block argument is used within the body" do
source = Source.new %(
(1..3).map { |i| i * i }
(1..3).map { |j| j * j.to_i64 }
(1..3).map { |k| k.to_i64 * k }
(1..3).map { |l| l.to_i64 * l.to_i64 }
(1..3).map { |m| m.to_s[start: m.to_i64, count: 3]? }
(1..3).map { |n| n.to_s.split.map { |z| n.to_i * z.to_i }.join }
)
subject.catch(source).should be_valid
end
it "reports if there is a call with a collapsible block" do
source = Source.new %(
(1..3).any? { |i| i.odd? }
)
subject.catch(source).should_not be_valid
end
it "reports if there is a call with an argument + collapsible block" do
source = Source.new %(
(1..3).join('.') { |i| i.to_s }
)
subject.catch(source).should_not be_valid
end
it "reports if there is a call with a collapsible block (with chained call)" do
source = Source.new %(
(1..3).map { |i| i.to_s.split.reverse.join.strip }
)
subject.catch(source).should_not be_valid
end
context "properties" do
it "#exclude_calls_with_block" do
source = Source.new %(
(1..3).in_groups_of(1) { |i| i.map(&.to_s) }
)
rule = VerboseBlock.new
rule
.tap(&.exclude_calls_with_block = true)
.catch(source).should be_valid
rule
.tap(&.exclude_calls_with_block = false)
.catch(source).should_not be_valid
end
it "#exclude_multiple_line_blocks" do
source = Source.new %(
(1..3).any? do |i|
i.odd?
end
)
rule = VerboseBlock.new
rule
.tap(&.exclude_multiple_line_blocks = true)
.catch(source).should be_valid
rule
.tap(&.exclude_multiple_line_blocks = false)
.catch(source).should_not be_valid
end
it "#exclude_prefix_operators" do
source = Source.new %(
(1..3).sum { |i| +i }
(1..3).sum { |i| -i }
)
rule = VerboseBlock.new
rule
.tap(&.exclude_prefix_operators = true)
.catch(source).should be_valid
rule
.tap(&.exclude_prefix_operators = false)
.catch(source).should_not be_valid
end
it "#exclude_operators" do
source = Source.new %(
(1..3).sum { |i| i * 2 }
)
rule = VerboseBlock.new
rule
.tap(&.exclude_operators = true)
.catch(source).should be_valid
rule
.tap(&.exclude_operators = false)
.catch(source).should_not be_valid
end
it "#exclude_setters" do
source = Source.new %(
Char::Reader.new("abc").tap { |reader| reader.pos = 0 }
)
rule = VerboseBlock.new
rule
.tap(&.exclude_setters = true)
.catch(source).should be_valid
rule
.tap(&.exclude_setters = false)
.catch(source).should_not be_valid
end
it "#max_line_length" do
source = Source.new %(
(1..3).tap &.tap &.tap &.tap &.tap &.tap &.tap do |i|
i.to_s.reverse.strip.blank?
end
)
rule = VerboseBlock.new
rule
.tap(&.max_line_length = 60)
.catch(source).should be_valid
rule
.tap(&.max_line_length = nil)
.catch(source).should_not be_valid
end
it "#max_length" do
source = Source.new %(
(1..3).tap { |i| i.to_s.split.reverse.join.strip.blank? }
)
rule = VerboseBlock.new
rule
.tap(&.max_length = 30)
.catch(source).should be_valid
rule
.tap(&.max_length = nil)
.catch(source).should_not be_valid
end
end
context "macro" do
it "reports in macro scope" do
source = Source.new %(
{{ (1..3).any? { |i| i.odd? } }}
)
subject.catch(source).should_not be_valid
end
end
it "reports call args and named_args" do
short_block_variants = {
%|map(&.to_s.[start: 0.to_i64, count: 3]?)|,
%|map(&.to_s.[0.to_i64, count: 3]?)|,
%|map(&.to_s.[0.to_i64, 3]?)|,
%|map(&.to_s.[start: 0.to_i64, count: 3]=("foo"))|,
%|map(&.to_s.[0.to_i64, count: 3]=("foo"))|,
%|map(&.to_s.[0.to_i64, 3]=("foo"))|,
%|map(&.to_s.camelcase(lower: true))|,
%|map(&.to_s.camelcase)|,
%|map(&.to_s.gsub('_', '-'))|,
%|map(&.in?(*{1, 2, 3}, **{foo: :bar}))|,
%|map(&.in?(1, *foo, 3, **bar))|,
%|join(separator: '.', &.to_s)|,
}
source = Source.new path: "source.cr", code: %(
(1..3).map { |i| i.to_s[start: 0.to_i64, count: 3]? }
(1..3).map { |i| i.to_s[0.to_i64, count: 3]? }
(1..3).map { |i| i.to_s[0.to_i64, 3]? }
(1..3).map { |i| i.to_s[start: 0.to_i64, count: 3] = "foo" }
(1..3).map { |i| i.to_s[0.to_i64, count: 3] = "foo" }
(1..3).map { |i| i.to_s[0.to_i64, 3] = "foo" }
(1..3).map { |i| i.to_s.camelcase(lower: true) }
(1..3).map { |i| i.to_s.camelcase }
(1..3).map { |i| i.to_s.gsub('_', '-') }
(1..3).map { |i| i.in?(*{1, 2, 3}, **{foo: :bar}) }
(1..3).map { |i| i.in?(1, *foo, 3, **bar) }
(1..3).join(separator: '.') { |i| i.to_s }
)
subject.catch(source).should_not be_valid
source.issues.size.should eq(short_block_variants.size)
source.issues.each_with_index do |issue, i|
issue.message.should eq(VerboseBlock::MSG % short_block_variants[i])
end
end
it "reports rule, pos and message" do
source = Source.new path: "source.cr", code: %(
(1..3).any? { |i| i.odd? }
)
subject.catch(source).should_not be_valid
source.issues.size.should eq 1
issue = source.issues.first
issue.rule.should_not be_nil
issue.location.to_s.should eq "source.cr:1:8"
issue.end_location.to_s.should eq "source.cr:1:26"
issue.message.should eq "Use short block notation instead: `any?(&.odd?)`"
end
end
end

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@ -4,9 +4,7 @@ module Ameba
describe Severity do
describe "#symbol" do
it "returns the symbol for each severity in the enum" do
Severity.values.each do |severity|
severity.symbol.should_not be_nil
end
Severity.values.each(&.symbol.should_not(be_nil))
end
it "returns symbol for Error" do

View file

@ -78,7 +78,7 @@ module Ameba::AST
# scope.find_variable("foo")
# ```
def find_variable(name : String)
variables.find { |v| v.name == name } || outer_scope.try &.find_variable(name)
variables.find(&.name.==(name)) || outer_scope.try &.find_variable(name)
end
# Creates a new assignment for the variable.

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@ -11,7 +11,7 @@ module Ameba
rejected = rejected_globs(globs)
selected = globs - rejected
expand(selected) - expand(rejected.map! { |p| p[1..-1] })
expand(selected) - expand(rejected.map!(&.[1..-1]))
end
# Expands globs. Globs can point to files or even directories.

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@ -0,0 +1,224 @@
module Ameba::Rule::Style
# This rule is used to identify usage of single expression blocks with
# argument as a receiver, that can be collapsed into a short form.
#
# For example, this is considered invalid:
#
# ```
# (1..3).any? { |i| i.odd? }
# ```
#
# And it should be written as this:
#
# ```
# (1..3).any?(&.odd?)
# ```
#
# YAML configuration example:
#
# ```
# Style/VerboseBlock:
# Enabled: true
# ExcludeMultipleLineBlocks: true
# ExcludeCallsWithBlocks: false
# ExcludePrefixOperators: true
# ExcludeOperators: false
# ExcludeSetters: false
# MaxLineLength: ~
# MaxLength: 50 # use ~ to disable
# ```
class VerboseBlock < Base
properties do
description "Identifies usage of collapsible single expression blocks."
exclude_calls_with_block true
exclude_multiple_line_blocks false
exclude_prefix_operators true
exclude_operators false
exclude_setters false
max_line_length : Int32? = nil # 100
max_length : Int32? = 50
end
MSG = "Use short block notation instead: `%s`"
CALL_PATTERN = "%s(%s&.%s)"
protected def same_location_lines?(a, b)
return unless a_location = a.name_location
return unless b_location = b.location
a_location.line_number == b_location.line_number
end
private PREFIX_OPERATORS = {"+", "-"}
private OPERATOR_CHARS =
{'[', ']', '!', '=', '>', '<', '~', '+', '-', '*', '/', '%', '^', '|', '&'}
protected def prefix_operator?(node)
node.name.in?(PREFIX_OPERATORS) && node.args.empty?
end
protected def operator?(name)
name.each_char do |char|
return false unless char.in?(OPERATOR_CHARS)
end
!name.empty?
end
protected def setter?(name)
!name.empty? && name[0].letter? && name.ends_with?('=')
end
protected def valid_length?(code)
if max_length = self.max_length
return code.size <= max_length
end
true
end
protected def valid_line_length?(node, code)
if max_line_length = self.max_line_length
if location = node.name_location
final_line_length = location.column_number + code.size
return final_line_length <= max_line_length
end
end
true
end
protected def reference_count(node, obj : Crystal::Var)
i = 0
case node
when Crystal::Call
i += reference_count(node.obj, obj)
i += reference_count(node.block, obj)
node.args.each do |arg|
i += reference_count(arg, obj)
end
node.named_args.try &.each do |arg|
i += reference_count(arg.value, obj)
end
when Crystal::Block
i += reference_count(node.body, obj)
when Crystal::Var
i += 1 if node == obj
end
i
end
protected def args_to_s(io : IO, node : Crystal::Call, skip_last_arg = false)
node.args.dup.tap do |args|
args.pop? if skip_last_arg
args.join io, ", "
node.named_args.try do |named_args|
io << ", " unless args.empty? || named_args.empty?
named_args.join io, ", " do |arg, inner_io|
inner_io << arg.name << ": " << arg.value
end
end
end
end
protected def node_to_s(node : Crystal::Call)
String.build do |str|
case name = node.name
when "[]"
str << '['
args_to_s(str, node)
str << ']'
when "[]?"
str << '['
args_to_s(str, node)
str << "]?"
when "[]="
str << '['
args_to_s(str, node, skip_last_arg: true)
str << "]=(" << node.args.last? << ')'
else
str << name
if !node.args.empty? || (node.named_args && !node.named_args.try(&.empty?))
str << '('
args_to_s(str, node)
str << ')'
end
str << " {...}" if node.block
end
end
end
protected def call_code(call, body)
args = String.build { |io| args_to_s(io, call) }.presence
args += ", " if args
call_chain = %w[].tap do |arr|
obj = body.obj
while obj.is_a?(Crystal::Call)
arr << node_to_s(obj)
obj = obj.obj
end
arr.reverse!
arr << node_to_s(body)
end
name =
call_chain.join('.')
CALL_PATTERN % {call.name, args, name}
end
# ameba:disable Metrics/CyclomaticComplexity
protected def issue_for_valid(source, call : Crystal::Call, body : Crystal::Call)
return if exclude_calls_with_block && body.block
return if exclude_multiple_line_blocks && !same_location_lines?(call, body)
return if exclude_prefix_operators && prefix_operator?(body)
return if exclude_operators && operator?(body.name)
return if exclude_setters && setter?(body.name)
call_code =
call_code(call, body)
return unless valid_line_length?(call, call_code)
return unless valid_length?(call_code)
issue_for call.name_location, call.end_location,
MSG % call_code
end
def test(source, node : Crystal::Call)
# we are interested only in calls with block taking a single argument
#
# ```
# (1..3).any? { |i| i.to_i64.odd? }
# ^--- ^ ^------------
# block arg body
# ```
return unless (block = node.block) && block.args.size == 1
arg = block.args.first
# we skip auto-generated blocks - `(1..3).any?(&.odd?)`
return if arg.name.starts_with?("__arg")
# we filter out the blocks that are of call type - `i.to_i64.odd?`
return unless (body = block.body).is_a?(Crystal::Call)
# we need to "unwind" the chain challs, so the final receiver object
# ends up being a variable - `i`
obj = body.obj
while obj.is_a?(Crystal::Call)
obj = obj.obj
end
# only calls with a first argument used as a receiver are the valid game
return unless obj == arg
# we bail out if the block node include the block argument
return if reference_count(body, arg) > 1
# add issue if the given nodes pass all of the checks
issue_for_valid source, node, body
end
end
end

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@ -126,7 +126,7 @@ module Ameba
@sources.all? do |source|
source.issues
.reject(&.disabled?)
.none? { |issue| issue.rule.severity <= @severity }
.none?(&.rule.severity.<=(@severity))
end
end