.rubocop.yml

inherit_from: .rubocop_todo.yml

require:
  - rubocop-performance
  - rubocop-rspec

AllCops:
  TargetRubyVersion: 2.5 # Lowest version supported as of Rubocop 0.13.0
  Include:
    - 'lib/**/*.rb'
    - 'ext/**/*.rb'
    - 'test/**/*.rb'
    - 'spec/**/*.rb'
    - 'Gemfile'
    - 'Rakefile'
  Exclude:
    - 'Appraisals'
    - '*.gemspec'
    - 'lib/ddtrace/**/vendor/**/*.rb'
    - 'integration/apps/*/bin/*'
    - 'integration/apps/*/Gemfile'
    - 'lib/ddtrace/profiling/pprof/pprof_pb.rb'
  NewCops: disable # Don't allow new cops to be enabled implicitly.

# 80 characters is a nice goal, but not worth currently changing in existing
# code for the sake of changing it to conform to a length set in 1928 (IBM).
Layout/LineLength:
  Max: 124

# These exceptions are good goals to attain, and probably will over time,
# so periodic disabling and re-running to inspect values is suggested.

Metrics/AbcSize:
  Max: 50

# TODO: As refactors continue, this should drop. However, the goal of
# 10 lines in a method may be a little lofty.
Metrics/MethodLength:
  Max: 36

Performance/Casecmp:
  Enabled: false

# TODO: this is not compliant with the Ruby community style guide. We
# should enable again this rule but it will change the public API because
# we're using set_ methods. We should work on that because also Rails
# honors this rule.
Naming/AccessorMethodName:
  Enabled: false

Style/RescueModifier:
  Enabled: false

Style/NumericLiterals:
  Enabled: false

Metrics/ClassLength:
  Max: 140

Metrics/BlockLength:
  Max: 42
  Exclude:
    - test/**/*
    - spec/**/*

Metrics/ParameterLists:
  Enabled: false

Metrics/CyclomaticComplexity:
  Max: 15

Metrics/PerceivedComplexity:
  Max: 15

Lint/UnusedMethodArgument:
  Enabled: false

Style/RescueStandardError:
  Enabled: false

# alias and alias_method are not equivalent
Style/Alias:
  Enabled: false

# Disabling advices that would lead to incompatible Ruby 1.9 code
Style/SymbolArray:
  Enabled: false

# Simple conditionals are perfectly fine, and more readable for multiline
# expressions.
Style/GuardClause:
  Enabled: false

# Case equality is not intrinsically problematic.
Style/CaseEquality:
  Enabled: false

# New cops since Rubocop 1.0.
# We have to explicitly opt-in for new cops to apply
# before the next major release.
Gemspec/DateAssignment: # (new in 1.10)
  Enabled: true
Layout/SpaceBeforeBrackets: # (new in 1.7)
  Enabled: true
Lint/AmbiguousAssignment: # (new in 1.7)
  Enabled: true
Lint/DeprecatedConstants: # (new in 1.8)
  Enabled: true
Lint/DuplicateBranch: # (new in 1.3)
  Enabled: true
Lint/DuplicateRegexpCharacterClassElement: # (new in 1.1)
  Enabled: true
Lint/EmptyClass: # (new in 1.3)
  Enabled: true
Lint/LambdaWithoutLiteralBlock: # (new in 1.8)
  Enabled: true
Lint/NoReturnInBeginEndBlocks: # (new in 1.2)
  Enabled: true
Lint/NumberedParameterAssignment: # (new in 1.9)
  Enabled: true
Lint/OrAssignmentToConstant: # (new in 1.9)
  Enabled: true
Lint/RedundantDirGlobSort: # (new in 1.8)
  Enabled: true
Lint/SymbolConversion: # (new in 1.9)
  Enabled: true
Lint/ToEnumArguments: # (new in 1.1)
  Enabled: true
Lint/TripleQuotes: # (new in 1.9)
  Enabled: true
Lint/UnexpectedBlockArity: # (new in 1.5)
  Enabled: true
Lint/UnmodifiedReduceAccumulator: # (new in 1.1)
  Enabled: true
Style/ArgumentsForwarding: # (new in 1.1)
  Enabled: true
Style/DocumentDynamicEvalDefinition: # (new in 1.1)
  Enabled: true
Style/EndlessMethod: # (new in 1.8)
  Enabled: true
Style/HashExcept: # (new in 1.7)
  Enabled: true
Style/IfWithBooleanLiteralBranches: # (new in 1.9)
  Enabled: true
Style/NilLambda: # (new in 1.3)
  Enabled: true
Style/RedundantArgument: # (new in 1.4)
  Enabled: true
Style/SwapValues: # (new in 1.1)
  Enabled: true
Performance/AncestorsInclude: # (new in 1.7)
  Enabled: true
Performance/BigDecimalWithNumericArgument: # (new in 1.7)
  Enabled: true
Performance/BlockGivenWithExplicitBlock: # (new in 1.9)
  Enabled: true
Performance/CollectionLiteralInLoop: # (new in 1.8)
  Enabled: true
Performance/ConstantRegexp: # (new in 1.9)
  Enabled: true
Performance/MethodObjectAsBlock: # (new in 1.9)
  Enabled: true
Performance/RedundantSortBlock: # (new in 1.7)
  Enabled: true
Performance/RedundantStringChars: # (new in 1.7)
  Enabled: true
Performance/ReverseFirst: # (new in 1.7)
  Enabled: true
Performance/SortReverse: # (new in 1.7)
  Enabled: true
Performance/Squeeze: # (new in 1.7)
  Enabled: true
Performance/StringInclude: # (new in 1.7)
  Enabled: true
Performance/Sum: # (new in 1.8)
  Enabled: true

# Requires Ruby 2.2
Style/HashSyntax:
  Enabled: false

# Requires Ruby 2.3
Style/SafeNavigation:
  Enabled: false

# Requires Ruby 2.3
Performance/UnfreezeString:
  Enabled: false

# Requires Ruby 2.4
Style/HashTransformValues:
  Enabled: false

# Requires Ruby 2.4
Style/CollectionCompact:
  Enabled: false

# Requires Ruby 2.4
Performance/RegexpMatch:
  Enabled: false

# Requires Ruby 2.5
Style/RedundantBegin:
  Enabled: false

# Requires Ruby 2.5
Style/HashTransformKeys:
  Enabled: false

# Enforces negative/positive branching order,
# which can hurt readability.
Style/NegatedIfElseCondition:
  Enabled: false

# Converts `to change{foo.bar}` to `to change(foo, :bar)`.
# It doesn't seem to make it more readable, and doesn't work
# when `foo` has to be re-evaluated.
RSpec/ExpectChange:
  Enabled: false

# Readability is not meaningfully affected by enforcing
# `not_to` vs `to_not`.
RSpec/NotToNot:
  Enabled: false

# Enforces `subject` above all else, even `include_context`
# declarations.
RSpec/LeadingSubject:
  Enabled: false

# Enforces usage of `expect(subject)` instead of `is_expected`.
RSpec/ImplicitSubject:
  Enabled: false

# Enforces empty line after hook declaration.
RSpec/EmptyLineAfterHook:
  Enabled: false

# Enforces empty line after subject declaration.
RSpec/EmptyLineAfterSubject:
  Enabled: false

# Enforces empty line after last let declaration.
RSpec/EmptyLineAfterFinalLet:
  Enabled: false

# TODO: Disabling until we categorize which file are safe to do so.
Style/FrozenStringLiteralComment:
  Enabled: false

# Replaces `x == 0` with `x.zero?` and similar.
# These methods are ~2x slower than the simple math comparison.
Style/NumericPredicate:
  Enabled: false

# Allow for empty blocks (without a comment) in tests.
Lint/EmptyBlock:
  Exclude:
    - 'test/**/*.rb'
    - 'spec/**/*.rb'

# Enforces that context description must start with 'when', 'with', or 'without'.
RSpec/ContextWording:
  Enabled: false

# Checks for multiple top-level example groups.
# Multiple descriptions for the same class or module should either
# be nested or separated into different test files.
RSpec/MultipleDescribes:
  Enabled: false

# Enforces that examples should only have a limited amount of assertions.
RSpec/MultipleExpectations:
  Enabled: false

# Enforces minimum character length for parameters.
Naming/MethodParameterName:
  Enabled: false

# Enforces no instance variable in specs.
RSpec/InstanceVariable:
  Enabled: false

# Enforces a maximum nested example group level.
RSpec/NestedGroups:
  Enabled: false

# Enforces `receive` vs `have_received` expectation pattern.
RSpec/MessageSpies:
  Enabled: false

# Enforces example line count limit.
RSpec/ExampleLength:
  Enabled: false

# Enforces maximum let and subject calls.
RSpec/MultipleMemoizedHelpers:
  Enabled: false

# Enforces `allow` over `expect` when configuring a response.
RSpec/StubbedMock:
  Enabled: false

# Enforces no use of `expect` in `before` hooks.
RSpec/ExpectInHook:
  Enabled: false

# Enforces no stubbing using `allow_any_instance_of`.
RSpec/AnyInstance:
  Enabled: false

# Enforces strict matching of example class with spec file name.
# This does not work for our current namespacing as our gem is called
# `ddtrace` while our namespace is `::Datadog`.
# It would have to either be `ddtrace` + `::DDTrace` or
# `datadog` + `::Datadog`.
RSpec/FilePath:
  Enabled: false

# Enforces no stubbing of methods of the object under test.
RSpec/SubjectStub:
  Enabled: false

# Enforces that the first argument to describe should
# be the class or module being tested.
RSpec/DescribeClass:
  Enabled: false

# Enforces to no use let! to setup objects not referenced in tests.
# Fails to account for shared examples across files.
RSpec/LetSetup:
  Enabled: false

# Identifies where `fetch(key) { value }` can be replaced by `fetch(key, value)`.
# Can't differentiate between `Hash#fetch` and `RailsCache#fetch`,
# passing in wrong parameters to these methods.
Style/RedundantFetchBlock:
  Enabled: false

# Warns about usage of `before(:all)`
RSpec/BeforeAfterAll:
  Enabled: false

# Enforces snake case file names.
Naming/FileName:
  Exclude:
    - 'integration/**/Gemfile'
    - 'integration/**/Rakefile'

# Enforces boolean parameters with default to be keyword arguments.
Style/OptionalBooleanParameter:
  Enabled: false