Parameter value used in file name Open
send_file(@record.full_filename, send_file_options)
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Using user input when accessing files (local or remote) will raise a warning in Brakeman.
For example
File.open("/tmp/#{cookie[:file]}")
will raise an error like
Cookie value used in file name near line 4: File.open("/tmp/#{cookie[:file]}")
This type of vulnerability can be used to access arbitrary files on a server (including /etc/passwd
.
Assignment Branch Condition size for show is too high. [70.3/15] Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
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This cop checks that the ABC size of methods is not higher than the configured maximum. The ABC size is based on assignments, branches (method calls), and conditions. See http://c2.com/cgi/wiki?AbcMetric
Method has too many lines. [44/10] Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
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This cop checks if the length of a method exceeds some maximum value. Comment lines can optionally be ignored. The maximum allowed length is configurable.
Method show
has a Cognitive Complexity of 26 (exceeds 5 allowed). Consider refactoring. Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Perceived complexity for show is too high. [12/7] Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
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This cop tries to produce a complexity score that's a measure of the
complexity the reader experiences when looking at a method. For that
reason it considers when
nodes as something that doesn't add as much
complexity as an if
or a &&
. Except if it's one of those special
case
/when
constructs where there's no expression after case
. Then
the cop treats it as an if
/elsif
/elsif
... and lets all the when
nodes count. In contrast to the CyclomaticComplexity cop, this cop
considers else
nodes as adding complexity.
Example:
def my_method # 1
if cond # 1
case var # 2 (0.8 + 4 * 0.2, rounded)
when 1 then func_one
when 2 then func_two
when 3 then func_three
when 4..10 then func_other
end
else # 1
do_something until a && b # 2
end # ===
end # 7 complexity points
Cyclomatic complexity for show is too high. [10/6] Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
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This cop checks that the cyclomatic complexity of methods is not higher than the configured maximum. The cyclomatic complexity is the number of linearly independent paths through a method. The algorithm counts decision points and adds one.
An if statement (or unless or ?:) increases the complexity by one. An else branch does not, since it doesn't add a decision point. The && operator (or keyword and) can be converted to a nested if statement, and ||/or is shorthand for a sequence of ifs, so they also add one. Loops can be said to have an exit condition, so they add one.
Method show
has 44 lines of code (exceeds 25 allowed). Consider refactoring. Open
def show
# Only respond to known types to avoid code injection attacks
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
# Ensure we load the correct object type
Use safe navigation (&.
) instead of checking if an object exists before calling the method. Open
logger.info "Sending X-Accel-Redirect header #{path}" if logger
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This cop transforms usages of a method call safeguarded by a non nil
check for the variable whose method is being called to
safe navigation (&.
).
Configuration option: ConvertCodeThatCanStartToReturnNil
The default for this is false
. When configured to true
, this will
check for code in the format !foo.nil? && foo.bar
. As it is written,
the return of this code is limited to false
and whatever the return
of the method is. If this is converted to safe navigation,
foo&.bar
can start returning nil
as well as what the method
returns.
Example:
# bad
foo.bar if foo
foo.bar(param1, param2) if foo
foo.bar { |e| e.something } if foo
foo.bar(param) { |e| e.something } if foo
foo.bar if !foo.nil?
foo.bar unless !foo
foo.bar unless foo.nil?
foo && foo.bar
foo && foo.bar(param1, param2)
foo && foo.bar { |e| e.something }
foo && foo.bar(param) { |e| e.something }
# good
foo&.bar
foo&.bar(param1, param2)
foo&.bar { |e| e.something }
foo&.bar(param) { |e| e.something }
foo.nil? || foo.bar
!foo || foo.bar
# Methods that `nil` will `respond_to?` should not be converted to
# use safe navigation
foo.to_i if foo
%w
-literals should be delimited by [
and ]
. Open
raise UnknownTypeError unless %w(documents image_files audio video).member?(params[:type])
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This cop enforces the consistent usage of %
-literal delimiters.
Specify the 'default' key to set all preferred delimiters at once. You can continue to specify individual preferred delimiters to override the default.
Example:
# Style/PercentLiteralDelimiters:
# PreferredDelimiters:
# default: '[]'
# '%i': '()'
# good
%w[alpha beta] + %i(gamma delta)
# bad
%W(alpha #{beta})
# bad
%I(alpha beta)
Favor modifier if
usage when having a single-line body. Another good alternative is the usage of control flow &&
/||
. Open
if SENDFILE_METHOD == 'apache'
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Checks for if and unless statements that would fit on one line
if written as a modifier if/unless. The maximum line length is
configured in the Metrics/LineLength
cop.
Example:
# bad
if condition
do_stuff(bar)
end
unless qux.empty?
Foo.do_something
end
# good
do_stuff(bar) if condition
Foo.do_something unless qux.empty?
The use of eval
is a serious security risk. Open
@record = eval(type.classify.to_s).find(id)
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This cop checks for the use of Kernel#eval
and Binding#eval
.
Example:
# bad
eval(something)
binding.eval(something)