Changelog

1.4.0

Credo's schema for pre-release names changes: There is now a . after the rc like in many other Elixir projects.
Add support for explaining checks (in addition to issues), i.e.
```
$ mix credo explain Credo.Check.Design.AliasUsage
```

Add support for tags on checks

Checks can now declare tags via the __using__ macro, i.e.

defmodule MyCheck do
  use Credo.Check, tags: [:foo]

  def run(source_file, params) do
    #
  end
end

Tags can be used via the CLI switch --checks-with[out]-tag:

# Only run checks tagged `:foo` during analysis
$ mix credo --checks-with-tag foo

# Exclude all checks tagged `:foo` from analysis
$ mix credo --checks-without-tag foo

Add validation of check params in config

If a param is not found, Credo checks for mispellings and suggests corrections:

$ mix credo
** (config) Credo.Check.Design.AliasUsage: unknown param `fi_called_more_often_than`. Did you mean `if_called_more_often_than`?

Add auto-generated check docs
Add new documentation on Hex with extra guides and CHANGELOG

1.3.2

Support non-ascii characters in variable names
Fix false positive in Credo.Check.Readability.ParenthesesOnZeroArityDefs

1.3.1

Fix new check (Credo.Check.Readability.StrictModuleLayout)
Ignore module attributes in UnsafeToAtom

1.3.0

Enable Credo.Check.Readability.UnnecessaryAliasExpansion check by default
Fix bugs when removing heredocs and charlists from sources
Fix false positive on TrailingWhiteSpace
Add ignore: [:fun1, :fun2] param to all UnusedOperation* checks; to ignore unused Enum.reduce/3 operations, use
```
{Credo.Check.Warning.UnusedEnumOperation, [ignore: [:reduce]]},
```

New switch to re-enable disabled checks

Use --enable-disabled-checks [pattern] to re-enable checks that were disabled in the config using {CheckModule, false}. This comes in handy when using checks on a case-by-case basis

As with other check-related switches, pattern is a comma-delimted list of patterns:

$ mix credo info --enable-disabled-checks Credo.Check.Readability.Specs,Credo.Check.Refactor.DoubleBooleanNegation

Of course, we can have the same effect by choosing the pattern less explicitly:

$ mix credo info --enable-disabled-checks specs,double

New API for custom checks

This deprecates the mandatory use of @explanation and @default_params module attributes for checks.

Before v1.3 you had to define module attributes named @explanation and @default_params before calling use Credo.Check.

Now you can pass :explanations (plural) and :param_defaults options directly to use Credo.Check.

defmodule MyCheck do
  use Credo.Check,
    category: :warning,
    base_priority: :high,
    param_defaults: [param1: 42, param2: "offline"],
    explanations: [
      check: "...",
      params: [
        param1: "Your favorite number",
        param2: "Online/Offline mode"
      ]
    ]

  def run(source_file, params) do
    #
  end
end

Please note that these options are also just a convenience to implement the functions specified by the Credo.Check behaviour. You can alternatively implement the respective functions yourself:

defmodule MyCheck do
  use Credo.Check

  def category, do: :warning

  def base_priority, do: :high

  def explanations do
    [
      check: "...",
      params: [
        param1: "Your favorite number",
        param2: "Online/Offline mode"
      ]
    ]
  end

  def param_defaults, do: [param1: 42, param2: "offline"]

  def run(source_file, params) do
    #
  end
end

New checks

1.2.3

Fix performance bottleneck in Credo.Service.ETSTableHelper

1.2.2

Fix token interpretation of Floats

1.2.1

Actually enable the new check (Credo.Check.Warning.MixEnv)

1.2.0

Commands can now have their own pipelines, so that plugins can extend them.
Add pipelines to SuggestCommand and ListCommand
Credo.Plugin.append_task/4 and Credo.Plugin.prepend_task/4 let you append/prepend tasks to Command's pipelines.
Validate options given to use Credo.Check
Fix TrailingWhiteSpace check on Windows
Fix MultiAlias to work with submodule expansion
Fix UnusedVariableNames bug
Fix Heredocs.replace_with_spaces/5 bug
Fix InterpolationHelper.replace_interpolations/2 bug
Fix crash in AliasAs check when MODULE is aliased
Fix speed pitfall in Scope.name/2
New config option: parse_timeout
Improved default settings for umbrella apps

New checks

Credo.Check.Warning.MixEnv

1.1.5

Add JSON output to categories and explain commands
Include number of executed checks in summary
Fix wrong trigger in SinglePipe

1.1.4

Fix name parsing bug in UnusedVariableNames
Fix bug when redefining operators in FunctionNames
Fix false positive in Specs

1.1.3

Improve warning message about skipped checks
Fix false positive in FunctionNames
Fix typespec in IssueMeta
Add AliasAs check to list of optional checks

1.1.2

Fix bug in Heredocs regarding indentation
Fix bug in FunctionNames when using unquote/1 in guards
Fix bug in FunctionNames when defining sigil_ functions for uppercase sigils

1.1.1

Fix incompatibilities between Elixir 1.9, Credo.Code.Token and Credo.Code.InterpolationHelper
Fix error in Heredocs with certain UTF-8 chars
New param for ParenthesesOnZeroArityDefs: use [parens: true] to force presence of parentheses on zero arity defs

1.1.0

Credo now requires Elixir 1.5 and Erlang/OTP 19
Fix false negative in DuplicatedCode
PipeChainStart has been made opt-in

Plugin Support

Credo now supports plugins that run alongside Credo's own analysis. While Credo provided the ability to write custom checks since v0.4.0, users can now access the complete toolset of Credo to create their own commands, require compilation, run external tools and still include the results in Credo's standard report.

Please refer to Credo's README as well as the Credo Demo Plugin for further information on how to get started.

New checks

Credo.Check.Refactor.WithClauses

1.0.5

Fix bug due to commented-out heredocs
Fix variable explanation for VariableRebinding check
Add MultiAlias check to experimental checks

1.0.4

Ignore heredocs in RedundantBlankLines
Fix bug in StringSigils
Minor refactorings

1.0.3

Fix bug in Name.full/1
Fix bug in UI.truncate/2
Disable LazyLogging for Elixir >= 1.7
Add UnnecessaryAliasExpansion check to experimental checks

1.0.2

Fix false positive in MapInto
Disable MapInto for Elixir 1.8 and higher
Ensure issues are sorted by filename, line number and column number
Warn about ineffective check filter patterns
Add ModuleDependencies check to experimental checks

1.0.1

Compilation warnings for Elixir 1.8
Fix StringSigils to not crash with strings containing non-UTF8 characters

1.0.0

Improve documentation
Add error handling for malformed config files
Write all warnings to :stderr
Fix false positive for charlists in PipeChainStart
Remove deprecated --one-line switch
Deactivate checks DuplicatedCode and DoubleBooleanNegation by default

BREAKING CHANGES

These changes concern people writing their own checks for Credo.

Credo.Check.CodeHelper was removed. Please use the corresponding functions inside the Credo.Code namespace.

0.10.2

Fix bug in AliasOrder

0.10.1

Fixed "unnecessary atom quotes" compiler warning during analysis
Handle timeouts when reading source files
Ignore function calls for OperationOnSameValues
Do not treat |> as an operator in SpaceAroundOperators
Fix AliasOrder bug for multi alias statements
Fix multiple false positives for SpaceAroundOperators
... and lots of important little fixes to issue messages, docs and the like!

0.10.0

Switch poison for jason
Add command-line switch to load a custom configuration file (--config-file)
Add a debug report in HTML format when running Credo using --debug
Add node_modules/ to default file excludes
Add :ignore_urls param for MaxLineLength
Report violation for not as well as ! in Refactor.NegatedConditionWithElse
Fix false positive on LargeNumbers
Fix NegatedConditionWithElse for not/2 as well
Disable PreferUnquotedAtoms for Elixir >= 1.7.0

New checks

Credo.Check.Refactor.MapInto

0.9.3

Fix bug in Scope
Fix false positive in MatchInConditionTest
Fix false positive in UnusedEnumOperation
Fix custom tasks by resolving config before validating it
Add text support to --min-priority CLI switch (you can now set it to low/normal/high)

New checks

Credo.Check.Readability.AliasOrder

0.9.2

Add :ignore_comments param to LongQuoteBlocks
Fix false positive in UnusedPathOperation

0.9.1

Fix false positive in SpaceAroundOperators
Fix false positive in UnusedEnumOperation

0.9.0

Add JSON support
Ensure compatibility with Elixir 1.6
Format codebase using Elixir 1.6 Formatter
Rework internals in preparation of 1.0 release
Credo now requires Elixir 1.4
Include test directory in default config
Add excluded_argument_types to PipeChainStart
Emit warnings for non-existing checks, which are referenced in config
Improve VariableNames
ModuleDoc now raises an issue for empty strings in @moduledoc tags
Fix bug on ModuleNames
Fix false positive in VariableRebinding
Fix false positive in SpaceAroundOperators
Fix false positive on BoolOperationOnSameValues
Fix false positive on SpaceAfterCommas
Fix false positive on MaxLineLength
Fix false positive in ParenthesesInCondition
Remove NameRedeclarationBy* checks
Remove support for @lint attributes

0.8.10

Maintenance release

0.8.9

Fix false positive in ParenthesesInCondition
Fix Code.to_tokens/1 for Elixir 1.6
Fix documentation for several checks

New checks

Credo.Check.Warning.ExpensiveEmptyEnumCheck

0.8.8

Fix false positive for LargeNumbers
Fix SpaceAroundOperators for @type module attributes
Ignore def arguments and specs for OperationOnSameValues
Fix crash in ParenthesesOnZeroArityDefs for variables named defp
Fix false positives for TagHelper

0.8.7

Fix false positive in ModuleAttributeNames
Fix false positives in unused return checks
Fix underlining in "list" action
Fix CLI argument parsing for mix credo.gen.check
Fix loading of custom checks
Prevent error when run against empty umbrella projects
Prevent output for tests

0.8.6

Fix false positive in SpaceAfterCommas
Fix false positive in SpaceAroundOperators
Fix bug with extracting explain command args
Allow anonymous functions to be piped as raw values

0.8.5

Speed up scope counting in CLI summary

0.8.4

Remove CheckForUpdates for good
Fix RaiseInsideRescue for implicit try

0.8.3

Do not run CheckForUpdates on CI systems and in editor integrations

0.8.2

Refactor all consistency checks, providing a nice speed improvement (thx @little-bobby-tables)
Improve Elixir 1.5 compatibility

0.8.1

Fix misleading issue message for LongQuoteBlocks

0.8.0

Load source files in parallel
Improve high memory consumption
Fix comment handling of Charlists, Sigils and Strings
LazyLogging now only checks for debug calls by default
Add --mute-exit-status CLI switch, which mutes Credo's exit status (this will be used for integration tests as it means that any non-zero exit status results from a runtime error of Credo)
Add default param values to mix explain output
TagTODO and TagFIXME now also report tags from doc-related module attributes (@doc, @moduledoc, @shortdoc)
Fix false positives for TrailingWhiteSpace
Fix compiler warnings for Sigils

BREAKING CHANGES

These changes concern people writing their own checks for Credo.

Credo.SourceFile struct was refactored: source, lines and ast are now stored in ETS tables.
Credo.Config struct was replaced by Credo.Execution.
run/3 callbacks for Credo.Check are now run/4 callbacks as they have to receive the execution's Credo.Execution struct.

Config Comments replace `@lint` attributes

@lint attributes are deprecated and will be removed in Credo 0.9.0 because they are causing a compiler warning in Elixir >= 1.4.

Users of Credo can now disable individual lines or files for all or just specific checks.

For now, config comments let you exclude individual files completely

# credo:disable-for-this-file
defmodule SomeApp.ThirdPartyCode do
end

or deactivate specific lines:

def my_fun do
  # credo:disable-for-next-line
  IO.inspect :this_is_actually_okay
end

or add the check module to exclude just that one check:

def my_fun do
  # credo:disable-for-next-line Credo.Check.Warning.IoInspect
  IO.inspect :this_is_actually_okay
end

or use a Regex to be more flexible which checks to exclude:

def my_fun do
  # credo:disable-for-next-line /IoInspect/
  IO.inspect :this_is_actually_okay
end

Here's a list with the syntax options:

# credo:disable-for-this-file - to disable for the entire file
# credo:disable-for-next-line - to disable for the next line
# credo:disable-for-previous-line - to disable for the previous line
# credo:disable-for-lines:<count> - to disable for the given number of lines (negative for previous lines)

New checks

Credo.Check.Refactor.LongQuoteBlocks

0.7.4

Fix false positives in SpacesAroundOperators
Fix --all CLI switch
Always enforce strict mode for <filename>:<line_no>
Improve docs on checks
Disable MultiAliasImportRequireUse by default

Disabled checks

Credo.Check.Consistency.MultiAliasImportRequireUse

0.7.3

Fix filename annotation when using --read-from-stdin
Fix filename handling on Windows
Fix consistency checks triggered by contents of sigils
Fix consistency checks triggered by contents of charlists

New check

Credo.Check.Warning.LazyLogging

0.7.2

Fix @lint attribute deprecation hint
Fix filename handling bug for Windows
Fix flycheck formatting
Add param to ignore strings/heredocs in TrailingWhiteSpace

New check

Credo.Check.Readability.SpaceAfterCommas

0.7.1

Fix --config_nameCLI switch
Fix UI.wrap_at/2 for Unicode strings
Fix false positive for ModuleNames

0.7.0

Added deprecation hint about @lint attributes
Fixed file inclusion/exclusion bug
Fixed false positives in SpaceAroundOperators
Deprecated NameRedeclarationBy* checks
Fixed false positives in PipeChainStart
Changed AppendSingleItem's priority and make it opt-in
Renamed NoParenthesesWhenZeroArity to ParenthesesOnZeroArityDefs
Fixed a bug in ParenthesesOnZeroArityDefs

Added/deprecated checks

Credo.Check.Warning.MapGetUnsafePass
Credo.Check.Refactor.AppendSingleItem
Credo.Check.Readability.Semicolons

Switched some checks to opt-in by default

Credo.Check.Readability.Specs
Credo.Check.Refactor.ABCSize
Credo.Check.Refactor.VariableRebinding
Credo.Check.Warning.MapGetUnsafePass
Credo.Check.Warning.NameRedeclarationByAssignment
Credo.Check.Warning.NameRedeclarationByCase
Credo.Check.Warning.NameRedeclarationByDef
Credo.Check.Warning.NameRedeclarationByFn

0.6.1

Fixed false positives for StringSigils in heredocs
Fixed a bug in SourceFile.column

0.6.0

Do not warn about ParenthesesInCondition in one-line if call
Add --no-strict CLI switch
Fixed exit status for mix credo list
Fixed exclusion of checks set to low priority

New Checks

consistency/multi_alias_import_require_use
readability/no_parentheses_when_zero_arity
readability/redundant_blank_lines
readability/single_pipe
readability/specs
readability/string_sigils
refactor/double_boolean_negation
refactor/variable_rebinding

0.5.3

Fix crash in CheckForUpdates

0.5.2

Add ability to specify strict in .credo.exs config file
Add no_case? to variable name checks
Add Module.name utility method
Fix bug in NameRedeclarationByDef
Fix bug in LargeNumbers

0.5.1

Use Hex.pm API to retrieve update information for Credo

0.5.0

See below

0.4.14

Fix compiler error due to usage of undocumented Hex APIs (sorry)

0.4.13

Prevent crashing when parsing non-UTF-8 source files
Fix yet another issue with finding sources
Fix false positives for PipeChainStart
Fix false positives for AbcSize
Remove dead code
Update deps

0.4.12

Prevent ModuleDoc from checking nested modules for ignored modules
Fix issue with ParenthesesInCondition
Fix issue with PipChainStart
Fix issue with reading from stdin
Log errors to stderr

0.4.11

Fix compatibility issues with Elixir < 1.2
Fix yet another issue with finding sources

0.4.10

Fix another issue with finding sources

0.4.9

Fix issues with finding sources
Don't enforce @moduledoc requirement for Mixfile or Test modules

0.4.8

Add exclude_functions option to PipeChainStart
No longer report issues in case of ambiguous aliases in AliasUsage
Fix false positives for LargeNumbers in Elixir >= 1.3.2 (again)
Lots of refactorings

0.4.7

Ignore module attributes like @spec in AliasUsage
Improve source file loading

0.4.6

Add ignore_specs option to MaxLineLength
Fix false positives for LargeNumbers in Elixir >= 1.3.2
Fix compiler warnings in preparation for Elixir v1.4

0.4.5

Warnings about redeclaring names of Kernel or local functions now only consider function of arity zero.
Warnings for operations with constant result now ignore division by 1
Better explanation how to configure checks in explain output

0.4.4

New check: readability/parentheses_in_condition

0.4.3

Fix compatibility issues in Credo.CLI.Command.GenCheck for Elixir < 1.2

0.4.2

Fix outdated comments regarding .credo.exs in README
Fix name generator including "Lib." prefix for custom checks

0.4.1

Maintenance release because I apparently don't understand how merging works :sweat:

0.4.0

Custom check support

Adds support for custom checks in your projects.

Using two new mix commands mix credo.gen.config and mix credo.gen.check you can generate the boilerplate to include custom checks in your projects.

BREAKING CHANGE: Checks listed in `.credo.exs`

Prior to v0.4.0, .credo.exs contained the full list of checks specific to your project
Starting with v0.4.0 the check list in credo.exs will be merged with the standard check list, with your definitions overwriting the defaults
PRO: you can customize individual tasks to your liking and still benefit from additional standard checks with each new release
CON: this means checks have to be disabled explicitly in .credo.exs

New Checks

readability/large_numbers
warning/bool_operation_on_same_values
warning/unused_file_operation
warning/unused_path_operation
warning/unused_regex_operation

Minor Improvements

Ready for Elixir 1.3
Checks for new Credo versions automatically, like Hex does (can be disabled)
Umbrella apps work out of the box now
DuplicatedCode can now ignore macro calls
ModuleDoc now ignores modules declaring exceptions
ModuleDoc now allows modules to be ignored based on their name
MatchInCondition now allows "simple" wildcard assignments in conditionals
Checks analysing all files in the codebase sequentially (consistency checks) are now run in parallel
If --only is given, all issues are shown (mix credo --only MaxLineLength previously yielded no results, since all issues needed --strict to actually be displayed)

0.3.13

Fix false positives for NameRedeclarationByDef.
Fix false positives for UnusedEnumOperation.

0.3.12

Fix false positives for SpaceInParentheses.
Fix false positive for SpaceAroundOperators.

0.3.11

Fix a bug with checks on function names when declaring a variable with the name def, defp or defmacro.

0.3.10

Fix a bug resulting in UnicodeConversionError for code containing UTF-8 comments.

0.3.9

Fix a bug in AliasUsage.

0.3.8

Fix false positives for AliasUsage.

0.3.7

Fix false positive for SpaceAroundOperators.

0.3.6

Fix false positives for SpaceAroundOperators and PipeChainStart.
Add option to read from STDIN for better editor integration

0.3.5

Remove superfluous call to IO.inspect.
Update deps requirements to make HexFaktor happy.

0.3.4

Fix false positives for SpaceAroundOperators in binary pattern matches.
Fix a bug when supplying a single file via the CLI.

0.3.3

Fix false positives for SpaceAroundOperators and SpaceInParentheses.

0.3.2

mix do credo, <something-else> was broken and never ran <something-else>, even if credo succeeded (exited with exit status 0). Now it runs <something-else> as long as credo succeeds.

0.3.1

Fix compiler warnings
Improve copywriting for consistency checks (thx @vdaniuk)

0.3.0

Per-function lint support

Adds support for @lint attributes used to configure linting for specific functions.

For now, this lets you exclude functions completely
```
@lint false
def my_fun do
end
```
or deactivate specific checks with the same syntax used in the config file:
```
@lint {Credo.Check.Design.TagTODO, false}
def my_fun do
end
```
or use a Regex instead of the check module to exclude multiple checks at once:
```
@lint {~r/Refactor/, false}
def my_fun do
end
```
Finally, you can supply multiple tuples as a list and combine the above:
```
@lint [{Credo.Check.Design.TagTODO, false}, {~r/Refactor/, false}]
def my_fun do
end
```

New Checks

consistency/space_around_operators
consistency/space_in_parentheses

Minor Improvements

Add --format CLI switch
Include experimental Flycheck support via --format=flycheck
Deprecate --one-line CLI switch, use --format=oneline instead
Add convenience alias --ignore for --ignore-checks
Fix colors for terminals with light backgrounds (thx @lucasmazza)

0.2.6

Fix false positives for UnusedEnumOperation checks (thx @kbaird)

0.2.5

Fix error occuring when a project has exactly one defexception module
Change the tag for Refactoring Opportunities from "[R]" to "[F]" (thx @rranelli)

0.2.4

Remove unused alias to avoid warning during compilation

0.2.3

Improves docs and UI wording (thx @crack and @jessejanderson)

0.2.2

Adds a missing word to the output of the categories command (thx @bakkdoor)

0.2.1

Fixes a problem with CaseTrivialMatches crashing

0.2.0

Error Status

Credo now fails with an exit status != 0 if it shows any issues. This will enable usage of Credo inside CI systems/build chains.

The exit status of each check is customizable and exit statuses of all encountered checks are collected, uniqued and summed:

issues
|> Enum.map(&(&1.exit_status))
|> Enum.uniq
|> Enum.reduce(0, &(&1+&2))

This way you can reason about the encountered issues right from the exit status.

Default values for the checks are based on their category:

consistency:  1
design:       2
readability:  4
refactor:     8
warning:     16

So an exit status of 12 tells you that you have only Readability Issues and Refactoring Opportunities, but e.g. no Warnings.

New Checks

readability/module_doc
refactor/case_trivial_matches
refactor/cond_statements
refactor/function_arity
refactor/match_in_condition
refactor/pipe_chain_start
warning/operation_with_constant_result
warning/unused_enum_operation
warning/unused_keyword_operation
warning/unused_list_operation
warning/unused_tuple_operation

Minor Improvements

There are two new aliases for command line switches:
- you can use --only as alias for --checks
- you can use --strict as alias for --all-priorities
mix credo --only <checkname> will always display a full list of results (you no longer need to specify --all separately)
mix credo explain <file:line_number> now also explains the available configuration parameters for the issue/check
The ExceptionNames check no longer fails if only a single exception module is found (#22).

0.1.10

Apply many fixes in anticipation of Elixir v1.2 (thx @c-rack)
Improve docs
Wrap long issue descriptions in suggest command

0.1.9

Add missing -A alias for --all-priorities
Improve wording in the CLI a bit

0.1.8

Add apps/ to default directories

0.1.7

Bugfix to NameRedeclarationBy\* checks
Sources.exclude had a bug when excluding directories

0.1.6

Rename CLI switch --pedantic to --all-priorities (alias is -A)
Fix a bug in SourceFile.column (#7)
Improve README section about basic usage, commands and issues

0.1.1 - 0.1.5

Multiple Hex releases due to the fact that I apparently don't understand how deps compilation works :sweat:

0.1.0

Initial release

v1.4.0

Changelog

1.4.0

1.3.2

1.3.1

1.3.0

New switch to re-enable disabled checks

New API for custom checks

New checks

1.2.3

1.2.2

1.2.1

1.2.0

New checks

1.1.5

1.1.4

1.1.3

1.1.2

1.1.1

1.1.0

Plugin Support

New checks

1.0.5

1.0.4

1.0.3

1.0.2

1.0.1

1.0.0

BREAKING CHANGES

0.10.2

0.10.1

0.10.0

New checks

0.9.3

New checks

0.9.2

0.9.1

0.9.0

0.8.10

0.8.9

New checks

0.8.8

0.8.7

0.8.6

0.8.5

0.8.4

0.8.3

0.8.2

0.8.1

0.8.0

BREAKING CHANGES

Config Comments replace @lint attributes

New checks

0.7.4

Disabled checks

0.7.3

New check

0.7.2

New check

0.7.1

0.7.0

Added/deprecated checks

0.6.1

0.6.0

New Checks

0.5.3

0.5.2

0.5.1

0.5.0

0.4.14

0.4.13

0.4.12

0.4.11

0.4.10

0.4.9

0.4.8

0.4.7

0.4.6

0.4.5

0.4.4

Config Comments replace `@lint` attributes

BREAKING CHANGE: Checks listed in `.credo.exs`