shard-ameba/spec/ameba/rule/lint/useless_assign_spec.cr
2024-01-22 17:15:52 +01:00

1086 lines
27 KiB
Crystal

require "../../../spec_helper"
module Ameba::Rule::Lint
describe UselessAssign do
subject = UselessAssign.new
.tap(&.exclude_type_declarations = false)
it "does not report used assignments" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 2
a
end
CRYSTAL
end
it "reports a useless assignment in a method" do
expect_issue subject, <<-CRYSTAL
def method
a = 2
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
it "reports a useless assignment in a proc" do
expect_issue subject, <<-CRYSTAL
->() {
a = 2
# ^ error: Useless assignment to variable `a`
}
CRYSTAL
end
it "reports a useless assignment in a block" do
expect_issue subject, <<-CRYSTAL
def method
3.times do
a = 1
# ^ error: Useless assignment to variable `a`
end
end
CRYSTAL
end
it "reports a useless assignment in a proc inside def" do
expect_issue subject, <<-CRYSTAL
def method
->() {
a = 2
# ^ error: Useless assignment to variable `a`
}
end
CRYSTAL
end
it "does not report ignored assignments" do
expect_no_issues subject, <<-CRYSTAL
payload, _header = decode
puts payload
CRYSTAL
end
it "reports a useless assignment in a proc inside a block" do
expect_issue subject, <<-CRYSTAL
def method
3.times do
->() {
a = 2
# ^ error: Useless assignment to variable `a`
}
end
end
CRYSTAL
end
it "does not report useless assignment of instance var" do
expect_no_issues subject, <<-CRYSTAL
class Cls
def initialize(@name)
end
end
CRYSTAL
end
it "does not report if assignment used in the inner block scope" do
expect_no_issues subject, <<-CRYSTAL
def method
var = true
3.times { var = false }
end
CRYSTAL
end
it "reports if assigned is not referenced in the inner block scope" do
expect_issue subject, <<-CRYSTAL
def method
var = true
# ^^^ error: Useless assignment to variable `var`
3.times {}
end
CRYSTAL
end
it "doesn't report if assignment in referenced in inner block" do
expect_no_issues subject, <<-CRYSTAL
def method
two = true
3.times do
mutex.synchronize do
two = 2
end
end
two.should be_true
end
CRYSTAL
end
it "reports if first assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method
var = true
# ^^^ error: Useless assignment to variable `var`
var = false
var
end
CRYSTAL
end
it "reports if variable reassigned and not used" do
expect_issue subject, <<-CRYSTAL
def method
var = true
# ^^^ error: Useless assignment to variable `var`
var = false
# ^^^ error: Useless assignment to variable `var`
end
CRYSTAL
end
it "does not report if variable used in a condition" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 1
if a
nil
end
end
CRYSTAL
end
it "reports second assignment as useless" do
expect_issue subject, <<-CRYSTAL
def method
a = 1
a = a + 1
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
it "does not report if variable is referenced in other assignment" do
expect_no_issues subject, <<-CRYSTAL
def method
if f = get_something
@f = f
end
end
CRYSTAL
end
it "does not report if variable is referenced in a setter" do
expect_no_issues subject, <<-CRYSTAL
def method
foo = 2
table[foo] ||= "bar"
end
CRYSTAL
end
it "does not report if variable is reassigned but not referenced" do
expect_issue subject, <<-CRYSTAL
def method
foo = 1
puts foo
foo = 2
# ^^^ error: Useless assignment to variable `foo`
end
CRYSTAL
end
it "does not report if variable is referenced in a call" do
expect_no_issues subject, <<-CRYSTAL
def method
if f = FORMATTER
@formatter = f.new
end
end
CRYSTAL
end
it "does not report if a setter is invoked with operator assignment" do
expect_no_issues subject, <<-CRYSTAL
def method
obj = {} of Symbol => Int32
obj[:name] = 3
end
CRYSTAL
end
context "block unpacking" do
it "does not report if the first arg is transformed and not used" do
expect_no_issues subject, <<-CRYSTAL
collection.each do |(a, b)|
puts b
end
CRYSTAL
end
it "does not report if the second arg is transformed and not used" do
expect_no_issues subject, <<-CRYSTAL
collection.each do |(a, b)|
puts a
end
CRYSTAL
end
it "does not report if all transformed args are not used in a block" do
expect_no_issues subject, <<-CRYSTAL
collection.each do |(foo, bar), (baz, _qux), index, object|
end
CRYSTAL
end
end
it "does not report if assignment is referenced in a proc" do
expect_no_issues subject, <<-CRYSTAL
def method
called = false
->() { called = true }
called
end
CRYSTAL
end
it "reports if variable is shadowed in inner scope" do
expect_issue subject, <<-CRYSTAL
def method
i = 1
# ^ error: Useless assignment to variable `i`
3.times do |i|
i + 1
end
end
CRYSTAL
end
it "does not report if parameter is referenced after the branch" do
expect_no_issues subject, <<-CRYSTAL
def method(param)
3.times do
param = 3
end
param
end
CRYSTAL
end
context "op assigns" do
it "does not report if variable is referenced below the op assign" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 1
a += 1
a
end
CRYSTAL
end
it "does not report if variable is referenced in op assign few times" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 1
a += 1
a += 1
a = a + 1
a
end
CRYSTAL
end
it "reports if variable is not referenced below the op assign" do
expect_issue subject, <<-CRYSTAL
def method
a = 1
a += 1
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
end
context "multi assigns" do
it "does not report if all assigns are referenced" do
expect_no_issues subject, <<-CRYSTAL
def method
a, b = {1, 2}
a + b
end
CRYSTAL
end
it "reports if one assign is not referenced" do
expect_issue subject, <<-CRYSTAL
def method
a, b = {1, 2}
# ^ error: Useless assignment to variable `b`
a
end
CRYSTAL
end
it "reports if both assigns are reassigned and useless" do
expect_issue subject, <<-CRYSTAL
def method
a, b = {1, 2}
# ^ error: Useless assignment to variable `a`
# ^ error: Useless assignment to variable `b`
a, b = {3, 4}
# ^ error: Useless assignment to variable `a`
# ^ error: Useless assignment to variable `b`
end
CRYSTAL
end
it "reports if both assigns are not referenced" do
expect_issue subject, <<-CRYSTAL
def method
a, b = {1, 2}
# ^ error: Useless assignment to variable `a`
# ^ error: Useless assignment to variable `b`
end
CRYSTAL
end
end
context "top level" do
it "reports if assignment is not referenced" do
expect_issue subject, <<-CRYSTAL
a = 1
# ^{} error: Useless assignment to variable `a`
a = 2
# ^{} error: Useless assignment to variable `a`
CRYSTAL
end
it "doesn't report if assignments are referenced" do
expect_no_issues subject, <<-CRYSTAL
a = 1
a += 1
a
b, c = {1, 2}
b
c
CRYSTAL
end
it "doesn't report if assignment is captured by block" do
expect_no_issues subject, <<-CRYSTAL
a = 1
3.times do
a = 2
end
CRYSTAL
end
it "doesn't report if assignment initialized and captured by block" do
expect_no_issues subject, <<-CRYSTAL
a : String? = nil
1.times do
a = "Fotis"
end
CRYSTAL
end
it "doesn't report record declaration" do
expect_no_issues subject, <<-CRYSTAL
record Foo, foo : String
record Foo, foo = "foo"
CRYSTAL
end
it "doesn't report record declarations (generics)" do
expect_no_issues subject, <<-CRYSTAL
record Foo(T), foo : T
record Foo(T), foo = T.new
CRYSTAL
end
pending "doesn't report type declaration as a call argument" do
expect_no_issues subject, <<-CRYSTAL
foo Foo(T), foo : T
foo Foo, foo : Nil
foo foo : String
foo foo : String, bar : Int32?, baz : Bool
CRYSTAL
end
it "doesn't report accessor declarations" do
accessor_macros = %w[setter class_setter]
%w[getter class_getter property class_property].each do |name|
accessor_macros << name
accessor_macros << "#{name}?"
accessor_macros << "#{name}!"
end
accessor_macros.each do |accessor|
expect_no_issues subject, <<-CRYSTAL
class Foo
#{accessor} foo : String?
#{accessor} bar = "bar"
end
CRYSTAL
end
end
it "does not report if assignment is referenced after the record declaration" do
expect_no_issues subject, <<-CRYSTAL
foo = 2
record Bar, foo = 3 # foo = 3 is not parsed as assignment
puts foo
CRYSTAL
end
it "reports if assignment is not referenced after the record declaration" do
expect_issue subject, <<-CRYSTAL
foo = 2
# ^ error: Useless assignment to variable `foo`
record Bar, foo = 3
CRYSTAL
end
it "doesn't report if type declaration assigned inside module and referenced" do
expect_no_issues subject, <<-CRYSTAL
module A
foo : String? = "foo"
bar do
foo = "bar"
end
p foo
end
CRYSTAL
end
it "reports if type declaration assigned inside class" do
expect_issue subject, <<-CRYSTAL
class A
foo : String? = "foo"
# ^^^ error: Useless assignment to variable `foo`
def method
foo = "bar"
# ^^^ error: Useless assignment to variable `foo`
end
end
CRYSTAL
end
end
context "branching" do
context "if-then-else" do
it "doesn't report if assignment is consumed by branches" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 0
if something
a = 1
else
a = 2
end
a
end
CRYSTAL
end
it "doesn't report if assignment is in one branch" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 0
if something
a = 1
else
nil
end
a
end
CRYSTAL
end
it "doesn't report if assignment is in one line branch" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 0
a = 1 if something
a
end
CRYSTAL
end
it "reports if assignment is useless in the branch" do
expect_issue subject, <<-CRYSTAL
def method(a)
if a
a = 2
# ^ error: Useless assignment to variable `a`
end
end
CRYSTAL
end
it "reports if only last assignment is referenced in a branch" do
expect_issue subject, <<-CRYSTAL
def method(a)
a = 1
if a
a = 2
# ^ error: Useless assignment to variable `a`
a = 3
end
a
end
CRYSTAL
end
it "does not report of assignments are referenced in all branches" do
expect_no_issues subject, <<-CRYSTAL
def method
if matches
matches = owner.lookup_matches signature
else
matches = owner.lookup_matches signature
end
matches
end
CRYSTAL
end
it "does not report referenced assignments in inner branches" do
expect_no_issues subject, <<-CRYSTAL
def method
has_newline = false
if something
do_something unless false
has_newline = false
else
do_something if true
has_newline = true
end
has_newline
end
CRYSTAL
end
end
context "unless-then-else" do
it "doesn't report if assignment is consumed by branches" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 0
unless something
a = 1
else
a = 2
end
a
end
CRYSTAL
end
it "reports if there is a useless assignment in a branch" do
expect_issue subject, <<-CRYSTAL
def method
a = 0
unless something
a = 1
# ^ error: Useless assignment to variable `a`
a = 2
else
a = 2
end
a
end
CRYSTAL
end
end
context "case" do
it "does not report if assignment is referenced" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
case a
when /foo/
a = 1
when /bar/
a = 2
end
puts a
end
CRYSTAL
end
it "reports if assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method(a)
case a
when /foo/
a = 1
# ^ error: Useless assignment to variable `a`
when /bar/
a = 2
# ^ error: Useless assignment to variable `a`
end
end
CRYSTAL
end
it "doesn't report if assignment is referenced in cond" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 2
case a
when /foo/
end
end
CRYSTAL
end
end
context "binary operator" do
it "does not report if assignment is referenced" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
(a = 1) && (b = 1)
a + b
end
CRYSTAL
end
it "reports if assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method(a)
(a = 1) || (b = 1)
# ^ error: Useless assignment to variable `b`
a
end
CRYSTAL
end
end
context "while" do
it "does not report if assignment is referenced" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
while a < 10
a = a + 1
end
a
end
CRYSTAL
end
it "reports if assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method(a)
while a < 10
b = a
# ^ error: Useless assignment to variable `b`
end
end
CRYSTAL
end
it "does not report if assignment is referenced in a loop" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 3
result = 0
while result < 10
result += a
a = a + 1
end
result
end
CRYSTAL
end
it "does not report if assignment is referenced as param in a loop" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
result = 0
while result < 10
result += a
a = a + 1
end
result
end
CRYSTAL
end
it "does not report if assignment is referenced in loop and inner branch" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
result = 0
while result < 10
result += a
if result > 0
a = a + 1
else
a = 3
end
end
result
end
CRYSTAL
end
it "works properly if there is branch with blank node" do
expect_no_issues subject, <<-CRYSTAL
def visit
count = 0
while true
break if count == 1
case something
when :any
else
:anything_else
end
count += 1
end
end
CRYSTAL
end
end
context "until" do
it "does not report if assignment is referenced" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
until a > 10
a = a + 1
end
a
end
CRYSTAL
end
it "reports if assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method(a)
until a > 10
b = a + 1
# ^ error: Useless assignment to variable `b`
end
end
CRYSTAL
end
end
context "exception handler" do
it "does not report if assignment is referenced in body" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
a = 2
rescue
a
end
CRYSTAL
end
it "doesn't report if assignment is referenced in ensure" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
a = 2
ensure
a
end
CRYSTAL
end
it "doesn't report if assignment is referenced in else" do
expect_no_issues subject, <<-CRYSTAL
def method(a)
a = 2
rescue
else
a
end
CRYSTAL
end
it "reports if assignment is useless" do
expect_issue subject, <<-CRYSTAL
def method(a)
rescue
a = 2
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
end
end
context "typeof" do
it "reports useless assignments in typeof" do
expect_issue subject, <<-CRYSTAL
typeof(begin
foo = 1
# ^^^ error: Useless assignment to variable `foo`
bar = 2
# ^^^ error: Useless assignment to variable `bar`
end)
CRYSTAL
end
end
context "macro" do
it "doesn't report if assignment is referenced in macro" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 2
{% if flag?(:bits64) %}
a.to_s
{% else %}
a
{% end %}
end
CRYSTAL
end
it "doesn't report referenced assignments in macro literal" do
expect_no_issues subject, <<-CRYSTAL
def method
a = 2
{% if flag?(:bits64) %}
a = 3
{% else %}
a = 4
{% end %}
puts a
end
CRYSTAL
end
it "doesn't report if assignment is referenced in macro def" do
expect_no_issues subject, <<-CRYSTAL
macro macro_call
puts x
end
def foo
x = 1
macro_call
end
CRYSTAL
end
it "doesn't report if assignment is referenced in a macro below" do
expect_no_issues subject, <<-CRYSTAL
class Foo
def foo
a = 1
macro_call
end
macro macro_call
puts a
end
end
CRYSTAL
end
it "doesn't report if assignment is referenced in a macro expression as string" do
expect_no_issues subject, <<-CRYSTAL
foo = 1
puts {{ "foo".id }}
CRYSTAL
end
it "doesn't report if assignment is referenced in for macro in exp" do
expect_no_issues subject, <<-CRYSTAL
foo = 22
{% for x in %w[foo] %}
add({{ x.id }})
{% end %}
CRYSTAL
end
it "doesn't report if assignment is referenced in for macro in body" do
expect_no_issues subject, <<-CRYSTAL
foo = 22
{% for x in %w[bar] %}
puts {{ "foo".id }}
{% end %}
CRYSTAL
end
it "doesn't report if assignment is referenced in if macro in cond" do
expect_no_issues subject, <<-CRYSTAL
foo = 22
{% if "foo".id %}
{% end %}
CRYSTAL
end
it "doesn't report if assignment is referenced in if macro in then" do
expect_no_issues subject, <<-CRYSTAL
foo = 22
{% if true %}
puts {{ "foo".id }}
{% end %}
CRYSTAL
end
it "doesn't report if assignment is referenced in if macro in else" do
expect_no_issues subject, <<-CRYSTAL
foo = 22
{% if true %}
{% else %}
puts {{ "foo".id }}
{% end %}
CRYSTAL
end
end
it "does not report if variable is referenced and there is a deep level scope" do
expect_no_issues subject, <<-CRYSTAL
response = JSON.build do |json|
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
json.object do
anything
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
end
response = JSON.parse(response)
response
CRYSTAL
end
context "type declaration" do
it "reports if it's not referenced at a top level" do
expect_issue subject, <<-CRYSTAL
a : String?
# ^{} error: Useless assignment to variable `a`
CRYSTAL
end
it "reports if it's not referenced in a method" do
expect_issue subject, <<-CRYSTAL
def foo
a : String?
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
it "reports if it's not referenced in a class" do
expect_issue subject, <<-CRYSTAL
class Foo
a : String?
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
it "doesn't report if it's referenced in a lib" do
expect_no_issues subject, <<-CRYSTAL
lib LibFoo
struct Foo
a : Int32
end
end
CRYSTAL
end
it "doesn't report if it's referenced" do
expect_no_issues subject, <<-CRYSTAL
def foo
a : String?
a
end
CRYSTAL
end
end
context "#properties" do
context "#exclude_type_declarations" do
it "doesn't report type declarations if enabled" do
rule = UselessAssign.new
rule.exclude_type_declarations = true
expect_no_issues rule, <<-CRYSTAL
a : String?
class Foo
b : String?
end
def foo
c : String?
end
CRYSTAL
end
end
end
context "uninitialized" do
it "reports if uninitialized assignment is not referenced at a top level" do
expect_issue subject, <<-CRYSTAL
a = uninitialized U
# ^{} error: Useless assignment to variable `a`
CRYSTAL
end
it "reports if uninitialized assignment is not referenced in a method" do
expect_issue subject, <<-CRYSTAL
def foo
a = uninitialized U
# ^ error: Useless assignment to variable `a`
end
CRYSTAL
end
it "doesn't report if uninitialized assignment is referenced" do
expect_no_issues subject, <<-CRYSTAL
def foo
a = uninitialized U
a
end
CRYSTAL
end
end
end
end