https://github.com/lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns

exhaustively list all specific cases if possible
https://github.com/lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns

case-of elm elm-review exhaustive explicit variant

Last synced: 20 days ago
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exhaustively list all specific cases if possible

• Host: GitHub
• URL: https://github.com/lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns
• Owner: lue-bird
• License: mit
• Created: 2024-10-03T18:19:05.000Z (3 months ago)
• Default Branch: main
• Last Pushed: 2024-10-23T09:40:32.000Z (2 months ago)
• Last Synced: 2024-12-09T18:02:07.567Z (24 days ago)
• Topics: case-of, elm, elm-review, exhaustive, explicit, variant
• Language: Elm
• Homepage: https://dark.elm.dmy.fr/packages/lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns/latest/
• Size: 68.4 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: changes.md
  • License: LICENSE

Awesome Lists containing this project

README

        
The [`elm-review`](https://package.elm-lang.org/packages/jfmengels/elm-review/latest/) rule

[`NoCatchAllForSpecificRemainingPatterns.rule`](https://package.elm-lang.org/packages/lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns/1.0.0/NoCatchAllForSpecificRemainingPatterns#rule) enforces that all specific cases are listed if possible.

Below would be reported for example

```elm

type Resource

    = Loaded String

    | FailedToLoad String

    | Loading

displayResource : Resource -> String

displayResource resource =

    case resource of

        Loaded text ->

            Ui.text text

        

        _ ->

            Ui.spinner

```

Try it:

```bash

elm-review --template lue-bird/elm-review-no-catch-all-for-specific-remaining-patterns/example

```

If you like it, add it, add it to your configuration

```elm

module ReviewConfig exposing (config)

import NoCatchAllForSpecificRemainingPatterns

import Review.Rule exposing (Rule)

config : List Rule

config =

    [ NoCatchAllForSpecificRemainingPatterns.rule

    ]

```

## why?

  - no accidentally missed cases:

    ```elm

    patternIsZero expression =

        case expression of

            Elm.Syntax.Pattern.IntPattern int ->

                int == 0

            

            _ ->

                -- accidentally missed HexPattern!

                False

    ```

  - a reminder if another variant is added in the future:

    ```elm

    type Resource

        = Loaded String

        | FailedToLoad String

        | Loading

        -- added

        | PartiallyLoaded String

    displayResource : Resource -> String

    displayResource resource =

        case resource of

            Loaded text ->

                Ui.text text

            

            _ ->

                -- we actually should display partially loaded

                -- but the compiler doesn't remind us

                Ui.spinner

    ```

  - less jumping around to understand the code

    ```elm

    case result of

        Ok geoLocation ->

            let

                ...

            in

            a

                bunchOf

                code

        _ ->

            -- what is _ ?

            0

    ```

## not implemented (yet?)

  - nested patterns like in tuples, variants or lists