# Recode
[](https://hex.pm/packages/recode)
[](https://github.com/hrzndhrn/recode/actions)
[](https://github.com/hrzndhrn//blob/main/LICENSE.md)
A linter with autocorrection and a refactoring tool.
`recode` is an experimental project to play around with the great
[`sourceror`](https://github.com/doorgan/sourceror) package by @doorgan.
This library is still under development, breaking changes are expected.
The same is true for `sourceror` and most of `recode`'s functionality is based
on `sourceror`.
For now, `recode` corrects only a few things:
* `AliasExpansion` expands multi aliases
* `AliasOrder` orders aliases alphabetically
* `Format` runs the Elixir formatter
* `PipeFunOne` adds `()` to one arity functions in pipes
* `SinglePipe` corrects single pipes
* `TestFileExt` renames test file extensions to `*.exs`
It is also possible to run `recode` in a none-autocorect mode to just lint your
code.
## Installation
The package can be installed by adding `recode` to your list of dependencies
in `mix.exs`:
```elixir
def deps do
[
{:recode, "~> 0.4", only: :dev}
]
end
```
`Recode` requires Elixir 1.13.0 or higher. If you add `recode` to a project that
supports lower Elixir versions you could add recode as following:
```elixir
def deps do
[
# your deps
] ++ recode()
end
defp recode() do
case Version.match?(System.version(), "~> 1.13") do
true -> [{:recode, "~> 0.3", only: :dev]}]
false -> []
end
end
```
Documentation can be found at [https://hexdocs.pm/recode](https://hexdocs.pm/recode).
## Usage
To start with Foo a configuration file is needed.
```sh
mix recode.gen.config
```
This mix task generates the config file `.recode.exs`.
```elixir
alias Recode.Task
[
version: "0.4.0",
# Can also be set/reset with "--autocorrect"/"--no-autocorrect".
autocorrect: true,
# With "--dry" no changes will be written to the files.
# Can also be set/reset with "--dry"/"--no-dry".
# If dry is true then verbose is also active.
dry: false,
# Can also be set/reset with "--verbose"/"--no-verbose".
verbose: false,
# Can be overwriten by calling `mix recode "lib/**/*.ex"`.
inputs: ["{config,lib,test}/**/*.{ex,exs}"],
formatter: {Recode.Formatter, []},
tasks: [
# Tasks could be added by a tuple of the tasks module name and an options
# keyword list. A task can be deactived by `active: false`. The execution of
# a deactivated task can be forced by calling `mix recode --task ModuleName`.
{Task.AliasExpansion, []},
{Task.AliasOrder, []},
{Task.EnforceLineLength, active: false},
{Task.PipeFunOne, []},
{Task.SinglePipe, []},
{Task.Specs, exclude: "test/**/*.{ex,exs}", config: [only: :visible]},
{Task.TestFileExt, []},
{Task.UnusedVariable, active: false}
]
]
```
### `mix recode`
This mix tasks runs the linter with autocorrection. The switch `--dry` prevents
the update of the files and shows all changes in the console.
```
> cd examples/my_code
> mix recode --dry
Found 13 files, including 2 scripts.
...........................................................................................
File: lib/my_code.ex
[Specs 15/3] Functions should have a @spec type specification.
File: lib/my_code/alias_expansion.ex
Updates: 1
Changed by: AliasExpansion
1 1 |defmodule MyCode.AliasExpansion do
2 - | alias MyCode.{PipeFunOne, SinglePipe}
2 + | alias MyCode.PipeFunOne
3 + | alias MyCode.SinglePipe
3 4 |
4 5 | def foo(x) do
...|
[Specs 5/3] Functions should have a @spec type specification.
File: lib/my_code/alias_order.ex
Updates: 2
Changed by: AliasOrder, AliasExpansion
...|
12 12 |
13 13 |defmodule Mycode.AliasOrder do
14 - | alias MyCode.SinglePipe
14 + | alias MyCode.Echo
15 + | alias MyCode.Foxtrot
15 16 | alias MyCode.PipeFunOne
16 - | alias MyCode.{Foxtrot, Echo}
17 + | alias MyCode.SinglePipe
17 18 |
18 19 | @doc false
...|
File: lib/my_code/fun.ex
Updates: 1
Changed by: Format
...|
2 2 | @moduledoc false
3 3 |
4 - |
5 - |
6 - |
7 - |
8 - |
9 4 | def noop(x), do: x
10 5 |end
...|
File: lib/my_code/multi.ex
Updates: 2
Changed by: SinglePipe, PipeFunOne
...|
7 7 |
8 8 | def pipe(x) do
9 - | x |> double |> double()
9 + | x |> double() |> double()
10 10 | end
11 11 |
12 12 | def single(x) do
13 - | x |> double()
13 + | double(x)
14 14 | end
15 15 |
...|
File: lib/my_code/pipe_fun_one.ex
Updates: 1
Changed by: PipeFunOne
...|
5 5 |
6 6 | def pipe(x) do
7 - | x |> double |> double()
7 + | x |> double() |> double()
8 8 | end
9 9 |end
...|
File: lib/my_code/same_line.ex
[Specs 2/3] Functions should have a @spec type specification.
File: lib/my_code/singel_pipe.ex
Updates: 1
Changed by: SinglePipe
...|
5 5 |
6 6 | def single_pipe(x) do
7 - | x |> double()
7 + | double(x)
8 8 | end
9 9 |
10 - | def reverse(a), do: a |> Enum.reverse()
10 + | def reverse(a), do: Enum.reverse(a)
11 11 |end
12 12 |
File: test/my_code_test.exs
Updates: 1
Changed by: TestFileExt
Moved from: test/my_code_test.ex
```
The switch `--no-autocorrect` runs the linter without any file changes.
```
> cd examples/my_code
> mix recode --no-autocorrect
Found 11 files, including 2 scripts.
.............................................................................
File: lib/my_code.ex
[Specs 15/3] Functions should have a @spec type specification.
File: lib/my_code/alias_expansion.ex
[AliasExpansion 2/3] Avoid multi aliases.
[Specs 4/3] Functions should have a @spec type specification.
File: lib/my_code/alias_order.ex
[AliasOrder 15/3] The alias `MyCode.PipeFunOne` is not alphabetically ordered among its group
[AliasOrder 16/3] The alias `MyCode` is not alphabetically ordered among its group
[AliasOrder 16/26] The alias `Echo` is not alphabetically ordered among its multi group
[AliasExpansion 16/3] Avoid multi aliases.
File: lib/my_code/fun.ex
[Format -/-] The file is not formatted.
File: lib/my_code/multi.ex
[PipeFunOne 9/7] Use parentheses for one-arity functions in pipes.
[SinglePipe 13/7] Use a function call when a pipeline is only one function long.
File: lib/my_code/pipe_fun_one.ex
[PipeFunOne 7/7] Use parentheses for one-arity functions in pipes.
File: lib/my_code/singel_pipe.ex
[SinglePipe 7/7] Use a function call when a pipeline is only one function long.
[SinglePipe 10/25] Use a function call when a pipeline is only one function long.
File: test/my_code_test.ex
[TestFileExt -/-] The file must be renamed to test/my_code_test.exs so that ExUnit can find it.
```
## Differences to Credo
`recode` was started as a plugin for `credo`. Unfortunately it was not possible
to implement autocorrection as a plugin because the traversation of the code does
not support changing the code.
Maybe some code lines from `recode` could be used as inspiration for `credo`
to bring the autocorrect feature to `credo`.
Other differences:
* `recode` requiers Elixir 1.13, `credo` requiers Elixir 1.7
* `recode` has autocorrection
* `credo` has much more checkers
* `credo` is faster
* `credo` has more features
