# Changelog

## Unreleased

### Compiler

- The compiler now reports an error when integer and float binary operators are
  used incorrectly in case expression guards.
  ([Adi Salimgereyev](https://github.com/abs0luty))

- The compiler now supports string concatenation in clause guards:

  ```gleam
  case message {
    #(version, action) if version <> ":" <> action == "v1:delete" ->
      handle_delete()
    _ -> ignore()
  }
  ```

  ([Adi Salimgereyev](https://github.com/abs0luty))

- Improved the code generated on the Erlang target when dividing a `Float`
  number by the literal number `0.0`.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

### Build tool

- When adding a package that does not exist on Hex, the message is a bit
  friendlier.
  ([Ameen Radwan](https://github.com/Acepie))

- The `gleam.toml` format is now consistent. The two sausage-case fields
  (`dev-dependencies` and `tag-prefix`) have been replaced by snake_case
  versions. Files using the old names will continue to work.
  ([Louis Pilfold](https://github.com/lpil))

- The password used for encrypting new local Hex API keys must now be at least
  8 characters in length.
  ([Louis Pilfold](https://github.com/lpil))

- The build tool now emits errors for unknown fields in package config,
  except ones under `[tools]`. For example, with this:

  ```toml
  name = "hello"
  version = "1.0.0"

  [tools.my-tool]
  my-awesome-setting = true
  ```

  Building the project won't give any errors. But with this:

  ```toml
  name = "hello"
  version = "1.0.0"
  my-awesome-setting = true
  ```

  Building the project will emit error.

  ([Andrey Kozhev](https://github.com/ankddev))

- When attempting to publish a package on Hex with an already taken name,
  the message is clearer.
  ([vyacheslavhere](https://github.com/vyacheslavhere))

- The build tool now shows better error message on passing unexpected labeled
  arguments by taking into account, whether it's a function or a constructor.
  ([Andrey Kozhev](https://github.com/ankddev))

### Language server

- The language server now allows extracting the start of a pipeline into a
  variable.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The language server is now smarter when producing autocompletions. Imagine
  you're updating your code to fully qualify the uses of the `Json` type:

  ```gleam
  pub fn payload() -> js|Json
  //                    ^ typing the module name
  ```

  Accepting the `json.Json` completion will now produce the correct `json.Json`
  annotation rather than generating invalid code: `json.JsonJson`.

  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The language server now suggests adding missing type parameters
  to custom generic types.
  ([Andi Pabst](https://github.com/andipabst))

- The `Extract function` code action now provides more ergonomic/idiomatic
  refactorings when used on anonymous functions.
  ([Hari Mohan](https://github.com/seafoamteal))

- It's now possible to find references and rename variables in string prefix
  patterns.

  ```gleam
  case wibble {
    "1" as digit <> rest -> digit <> rest
    //     ^^^^^    ^^^^
    // You can now trigger "Find references" and "Rename" from here
  }
  ```

  ([Igor Castejón](https://github.com/IgorCastejon))

- The language server now offers a rename for module when the cursor is placed
  over its import statement or when placed on its name or alias somewhere. For
  example,

  ```gleam
  import lustre/element
  import lustre/element/html
  import lustre/event

  fn view(model: Int) -> element.Element(Msg) {
    //                     ^  Renaming module to `el` here
    let count = int.to_string(model)

    html.div([], [
      html.button([event.on_click(Incr)], [element.text(" + ")]),
      html.p([], [element.text(count)]),
      html.button([event.on_click(Decr)], [element.text(" - ")]),
    ])
  }
  ```

  Using renaming when hovering on module name will would result in the
  following code:

  ```gleam
  import lustre/element as el
  import lustre/element/html
  import lustre/event

  fn view(model: Int) -> el.Element(Msg) {
    let count = int.to_string(model)

    html.div([], [
      html.button([event.on_click(Incr)], [el.text(" + ")]),
      html.p([], [el.text(count)]),
      html.button([event.on_click(Decr)], [el.text(" - ")]),
    ])
  }
  ```

  ([Vladislav Shakitskiy](https://github.com/vshakitskiy))

- The "Fill labels" code action now uses variables from scope when they match
  the label name and expected type, using shorthand syntax (`name:`) instead of
  `name: todo`.

  ([Vladislav Shakitskiy](https://github.com/vshakitskiy))

- The "Interpolate String" code action now lets the user "cut out" any portion
  of a string, regardless of whether it is a valid Gleam identifier or not.
  ([Hari Mohan](https://github.com/seafoamteal))

- When interpolating an expression at the very start or the very end
  of a string, redundant empty strings are no longer added before/after the
  interpolated expression.
  ([Hari Mohan](https://github.com/seafoamteal))

- The language server now performs best-effort zero value generation for
  `decode.failure` when using the `Generate Dynamic Decoder` code action.
  ([Hari Mohan](https://github.com/seafoamteal))

- The `Generate Dynamic Decoder` and `Generate To-JSON Function` code action
  now generate a decoder and an encoder, respectively, for `Nil` values.
  ([Hari Mohan](https://github.com/seafoamteal))

### Formatter

### Bug fixes

- Fixed a bug where some bit array patterns would erroneously be marked as
  unreachable.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed a bug where the Gleam standard library's `dict.each` function would
  incorrectly be assumed to be pure.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The compiler now correctly tracks the minimum required version for constant
  record updates to be `>= 1.14.0`.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The compiler now correctly tracks the minimum required version for
  expressions in `BitArray`s' `size` option to be `>= 1.12.0`.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed a bug where the formatter would not properly format some function calls
  if the last argument was followed by a trailing comment.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed a bug where the compiler would generate invalid code on the JavaScript
  target when using a `case` expression as the right hand side of an equality
  check in an `assert`.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed a bug where the compiler would generate invalid code on the JavaScript
  target for some `case` expressions using clause guards.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The formatter no longer stack overflows trying to format lists with many
  items.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed a bug where the formatter would not be able to consistently format a
  constant list with an `@internal` attribute.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The "convert to pipe" code action now works on nested function calls as well,
  rather than always being applied to the outermost one.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- The language server no longer recommends the deprecated `@target` attribute.
  ([Hari Mohan](https://github.com/seafoamteal))

- The compiler no longer crashes when trying to pattern match on a
  `UtfCodepoint`.
  ([Hari Mohan](https://github.com/seafoamteal))

- Fixed a bug that would result in not being able to rename an aliased pattern.
  ([Giacomo Cavalieri](https://github.com/giacomocavalieri))

- Fixed JavaScript codegen bug for `assert` when using `&&` with comparison
  operators on the right side.
  ([vyacheslavhere](https://github.com/vyacheslavhere))

- Added an error message when attempting to update packages that are not
  dependencies of the project, instead of failing silently.
  ([Etienne Boutet](https://github.com/EtienneBoutet),
  [Vladislav Shakitskiy](https://github.com/vshakitskiy))

- The build tool now doesn't perform code generation when exporting package
  interface.
  ([Andrey Kozhev](https://github.com/ankddev))

- The "Extract constant" code action now correctly places new constant when
  function has documentation. For example,

  ```gleam
  /// Wibble does some wobbling
  pub fn wibble() {
    let x = "wobble"
    //  ^ Trigger "Extract constant" here
    x
  }
  ```

  Previously, it would incorrectly place it below doc comment:

  ```gleam
  /// Wibble does some wobbling
  const x = "wobble"

  pub fn wibble() {
    x
  }
  ```

  Now it will correctly place constant above doc comment:

  ```gleam
  const x = "wobble"

  /// Wibble does some wobbling
  pub fn wibble() {
    x
  }
  ```

  ([Andrey Kozhev](https://github.com/ankddev))

- Fixed a bug where renaming would not work properly if there was an error in
  target file.
  ([Surya Rose](https://github.com/GearsDatapacks))

- Fixed a bug where generics in custom types would not be properly generated
  when emitting TypeScript declarations.
  ([Surya Rose](https://github.com/GearsDatapacks))

- Fixed a bug where the package cache would not properly be reset when a version
  of a package was replaced on Hex.
  ([Surya Rose](https://github.com/GearsDatapacks))

- Fixed a crash (`bad_generator`) that could occur when a linked OTP process
  exits with a non-standard exit reason.
  ([John Downey](https://github.com/jtdowney))

- Fixed a bug where diagnostic about incorrect `size` and `unit` options would
  use incorrect error location.
  ([Andrey Kozhev](https://github.com/ankddev))