tasafo/certifico

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.

You can set literals you want to fold with CountAsOne. Available are: 'array', 'hash', and 'heredoc'. Each literal will be counted as one line regardless of its actual size.

NOTE: The ExcludedMethods configuration is deprecated and only kept for backwards compatibility. Please use IgnoredMethods instead.

Example: CountAsOne: ['array', 'heredoc']

def m
  array = [       # +1
    1,
    2
  ]

  hash = {        # +3
    key: 'value'
  }

  <<~HEREDOC      # +1
    Heredoc
    content.
  HEREDOC
end               # 5 points

A method with Too Many Statements is any method that has a large number of lines.

Too Many Statements warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements counts +1 for every simple statement in a method and +1 for every statement within a control structure (if, else, case, when, for, while, until, begin, rescue) but it doesn't count the control structure itself.

So the following method would score +6 in Reek's statement-counting algorithm:

def parse(arg, argv, &error)
  if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
    return nil, block, nil                                         # +1
  end
  opt = (val = parse_arg(val, &error))[1]                          # +2
  val = conv_arg(*val)                                             # +3
  if opt and !arg
    argv.shift                                                     # +4
  else
    val[0] = nil                                                   # +5
  end
  val                                                              # +6
end

(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)

A method with Too Many Statements is any method that has a large number of lines.

Too Many Statements warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements counts +1 for every simple statement in a method and +1 for every statement within a control structure (if, else, case, when, for, while, until, begin, rescue) but it doesn't count the control structure itself.

So the following method would score +6 in Reek's statement-counting algorithm:

def parse(arg, argv, &error)
  if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
    return nil, block, nil                                         # +1
  end
  opt = (val = parse_arg(val, &error))[1]                          # +2
  val = conv_arg(*val)                                             # +3
  if opt and !arg
    argv.shift                                                     # +4
  else
    val[0] = nil                                                   # +5
  end
  val                                                              # +6
end

(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)

Feature Envy occurs when a code fragment references another object more often than it references itself, or when several clients do the same series of manipulations on a particular type of object.

Feature Envy reduces the code's ability to communicate intent: code that "belongs" on one class but which is located in another can be hard to find, and may upset the "System of Names" in the host class.

Feature Envy also affects the design's flexibility: A code fragment that is in the wrong class creates couplings that may not be natural within the application's domain, and creates a loss of cohesion in the unwilling host class.

Feature Envy often arises because it must manipulate other objects (usually its arguments) to get them into a useful form, and one force preventing them (the arguments) doing this themselves is that the common knowledge lives outside the arguments, or the arguments are of too basic a type to justify extending that type. Therefore there must be something which 'knows' about the contents or purposes of the arguments. That thing would have to be more than just a basic type, because the basic types are either containers which don't know about their contents, or they are single objects which can't capture their relationship with their fellows of the same type. So, this thing with the extra knowledge should be reified into a class, and the utility method will most likely belong there.

Example

Running Reek on:

class Warehouse
  def sale_price(item)
    (item.price - item.rebate) * @vat
  end
end

would report:

Warehouse#total_price refers to item more than self (FeatureEnvy)

since this:

(item.price - item.rebate)

belongs to the Item class, not the Warehouse.

Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.

Reek implements a check for Duplicate Method Call.

Example

Here's a very much simplified and contrived example. The following method will report a warning:

def double_thing()
  @other.thing + @other.thing
end

One quick approach to silence Reek would be to refactor the code thus:

def double_thing()
  thing = @other.thing
  thing + thing
end

A slightly different approach would be to replace all calls of double_thing by calls to @other.double_thing:

class Other
  def double_thing()
    thing + thing
  end
end

The approach you take will depend on balancing other factors in your code.

Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.

Reek implements a check for Duplicate Method Call.

Example

Here's a very much simplified and contrived example. The following method will report a warning:

def double_thing()
  @other.thing + @other.thing
end

One quick approach to silence Reek would be to refactor the code thus:

def double_thing()
  thing = @other.thing
  thing + thing
end

A slightly different approach would be to replace all calls of double_thing by calls to @other.double_thing:

class Other
  def double_thing()
    thing + thing
  end
end

The approach you take will depend on balancing other factors in your code.

Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.

Reek implements a check for Duplicate Method Call.

Example

Here's a very much simplified and contrived example. The following method will report a warning:

def double_thing()
  @other.thing + @other.thing
end

One quick approach to silence Reek would be to refactor the code thus:

def double_thing()
  thing = @other.thing
  thing + thing
end

A slightly different approach would be to replace all calls of double_thing by calls to @other.double_thing:

class Other
  def double_thing()
    thing + thing
  end
end

The approach you take will depend on balancing other factors in your code.

Duplication occurs when two fragments of code look nearly identical, or when two fragments of code have nearly identical effects at some conceptual level.

Reek implements a check for Duplicate Method Call.

Example

Here's a very much simplified and contrived example. The following method will report a warning:

def double_thing()
  @other.thing + @other.thing
end

One quick approach to silence Reek would be to refactor the code thus:

def double_thing()
  thing = @other.thing
  thing + thing
end

A slightly different approach would be to replace all calls of double_thing by calls to @other.double_thing:

class Other
  def double_thing()
    thing + thing
  end
end

The approach you take will depend on balancing other factors in your code.

A Utility Function is any instance method that has no dependency on the state of the instance.

A Utility Function is any instance method that has no dependency on the state of the instance.

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 and https://en.wikipedia.org/wiki/ABC_Software_Metric.

Interpreting ABC size:

• <= 17 satisfactory
• 18..30 unsatisfactory
• > 30 dangerous

You can have repeated "attributes" calls count as a single "branch". For this purpose, attributes are any method with no argument; no attempt is meant to distinguish actual attr_reader from other methods.

Example: CountRepeatedAttributes: false (default is true)

# `model` and `current_user`, refenced 3 times each,
 # are each counted as only 1 branch each if
 # `CountRepeatedAttributes` is set to 'false'

 def search
   @posts = model.active.visible_by(current_user)
             .search(params[:q])
   @posts = model.some_process(@posts, current_user)
   @posts = model.another_process(@posts, current_user)

   render 'pages/search/page'
 end

This cop also takes into account IgnoredMethods (defaults to [])

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 and https://en.wikipedia.org/wiki/ABC_Software_Metric.

Interpreting ABC size:

• <= 17 satisfactory
• 18..30 unsatisfactory
• > 30 dangerous

You can have repeated "attributes" calls count as a single "branch". For this purpose, attributes are any method with no argument; no attempt is meant to distinguish actual attr_reader from other methods.

Example: CountRepeatedAttributes: false (default is true)

# `model` and `current_user`, refenced 3 times each,
 # are each counted as only 1 branch each if
 # `CountRepeatedAttributes` is set to 'false'

 def search
   @posts = model.active.visible_by(current_user)
             .search(params[:q])
   @posts = model.some_process(@posts, current_user)
   @posts = model.another_process(@posts, current_user)

   render 'pages/search/page'
 end

This cop also takes into account IgnoredMethods (defaults to [])

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 and https://en.wikipedia.org/wiki/ABC_Software_Metric.

Interpreting ABC size:

• <= 17 satisfactory
• 18..30 unsatisfactory
• > 30 dangerous

You can have repeated "attributes" calls count as a single "branch". For this purpose, attributes are any method with no argument; no attempt is meant to distinguish actual attr_reader from other methods.

Example: CountRepeatedAttributes: false (default is true)

# `model` and `current_user`, refenced 3 times each,
 # are each counted as only 1 branch each if
 # `CountRepeatedAttributes` is set to 'false'

 def search
   @posts = model.active.visible_by(current_user)
             .search(params[:q])
   @posts = model.some_process(@posts, current_user)
   @posts = model.another_process(@posts, current_user)

   render 'pages/search/page'
 end

This cop also takes into account IgnoredMethods (defaults to [])

This cop checks the length of lines in the source code. The maximum length is configurable. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop. It also ignores a shebang line by default.

This cop has some autocorrection capabilities. It can programmatically shorten certain long lines by inserting line breaks into expressions that can be safely split across lines. These include arrays, hashes, and method calls with argument lists.

If autocorrection is enabled, the following Layout cops are recommended to further format the broken lines. (Many of these are enabled by default.)

• ArgumentAlignment
• BlockAlignment
• BlockDelimiters
• BlockEndNewline
• ClosingParenthesisIndentation
• FirstArgumentIndentation
• FirstArrayElementIndentation
• FirstHashElementIndentation
• FirstParameterIndentation
• HashAlignment
• IndentationWidth
• MultilineArrayLineBreaks
• MultilineBlockLayout
• MultilineHashBraceLayout
• MultilineHashKeyLineBreaks
• MultilineMethodArgumentLineBreaks
• ParameterAlignment

Together, these cops will pretty print hashes, arrays, method calls, etc. For example, let's say the max columns is 25:

Example:

# bad
{foo: "0000000000", bar: "0000000000", baz: "0000000000"}

# good
{foo: "0000000000",
bar: "0000000000", baz: "0000000000"}

# good (with recommended cops enabled)
{
  foo: "0000000000",
  bar: "0000000000",
  baz: "0000000000",
}

This cop checks the length of lines in the source code. The maximum length is configurable. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop. It also ignores a shebang line by default.

This cop has some autocorrection capabilities. It can programmatically shorten certain long lines by inserting line breaks into expressions that can be safely split across lines. These include arrays, hashes, and method calls with argument lists.

If autocorrection is enabled, the following Layout cops are recommended to further format the broken lines. (Many of these are enabled by default.)

• ArgumentAlignment
• BlockAlignment
• BlockDelimiters
• BlockEndNewline
• ClosingParenthesisIndentation
• FirstArgumentIndentation
• FirstArrayElementIndentation
• FirstHashElementIndentation
• FirstParameterIndentation
• HashAlignment
• IndentationWidth
• MultilineArrayLineBreaks
• MultilineBlockLayout
• MultilineHashBraceLayout
• MultilineHashKeyLineBreaks
• MultilineMethodArgumentLineBreaks
• ParameterAlignment

Together, these cops will pretty print hashes, arrays, method calls, etc. For example, let's say the max columns is 25:

Example:

# bad
{foo: "0000000000", bar: "0000000000", baz: "0000000000"}

# good
{foo: "0000000000",
bar: "0000000000", baz: "0000000000"}

# good (with recommended cops enabled)
{
  foo: "0000000000",
  bar: "0000000000",
  baz: "0000000000",
}

This cop checks the length of lines in the source code. The maximum length is configurable. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop. It also ignores a shebang line by default.

This cop has some autocorrection capabilities. It can programmatically shorten certain long lines by inserting line breaks into expressions that can be safely split across lines. These include arrays, hashes, and method calls with argument lists.

If autocorrection is enabled, the following Layout cops are recommended to further format the broken lines. (Many of these are enabled by default.)

• ArgumentAlignment
• BlockAlignment
• BlockDelimiters
• BlockEndNewline
• ClosingParenthesisIndentation
• FirstArgumentIndentation
• FirstArrayElementIndentation
• FirstHashElementIndentation
• FirstParameterIndentation
• HashAlignment
• IndentationWidth
• MultilineArrayLineBreaks
• MultilineBlockLayout
• MultilineHashBraceLayout
• MultilineHashKeyLineBreaks
• MultilineMethodArgumentLineBreaks
• ParameterAlignment

Together, these cops will pretty print hashes, arrays, method calls, etc. For example, let's say the max columns is 25:

Example:

# bad
{foo: "0000000000", bar: "0000000000", baz: "0000000000"}

# good
{foo: "0000000000",
bar: "0000000000", baz: "0000000000"}

# good (with recommended cops enabled)
{
  foo: "0000000000",
  bar: "0000000000",
  baz: "0000000000",
}

This cop checks the length of lines in the source code. The maximum length is configurable. The tab size is configured in the IndentationWidth of the Layout/IndentationStyle cop. It also ignores a shebang line by default.

This cop has some autocorrection capabilities. It can programmatically shorten certain long lines by inserting line breaks into expressions that can be safely split across lines. These include arrays, hashes, and method calls with argument lists.

If autocorrection is enabled, the following Layout cops are recommended to further format the broken lines. (Many of these are enabled by default.)

• ArgumentAlignment
• BlockAlignment
• BlockDelimiters
• BlockEndNewline
• ClosingParenthesisIndentation
• FirstArgumentIndentation
• FirstArrayElementIndentation
• FirstHashElementIndentation
• FirstParameterIndentation
• HashAlignment
• IndentationWidth
• MultilineArrayLineBreaks
• MultilineBlockLayout
• MultilineHashBraceLayout
• MultilineHashKeyLineBreaks
• MultilineMethodArgumentLineBreaks
• ParameterAlignment

Together, these cops will pretty print hashes, arrays, method calls, etc. For example, let's say the max columns is 25:

Example:

# bad
{foo: "0000000000", bar: "0000000000", baz: "0000000000"}

# good
{foo: "0000000000",
bar: "0000000000", baz: "0000000000"}

# good (with recommended cops enabled)
{
  foo: "0000000000",
  bar: "0000000000",
  baz: "0000000000",
}