- Fix an idempotency issue when rewriting where clauses in which rustfmt would continuously add a trailing comma `,` to the end of trailing line comments [#5941](https://github.com/rust-lang/rustfmt/issues/5941).
- When using `version=Two`, the `trace!` macro from the [log crate] is now formatted similarly to `debug!`, `info!`, `warn!`, and `error!` [#5987](https://github.com/rust-lang/rustfmt/issues/5987).
- Prevent enum variant attributes from wrapping one character early when using `version=Two` [#5801](https://github.com/rust-lang/rustfmt/issues/5801)
- Properly wrap macro matchers at the `max_width` when using `version=Two` and `format_macro_matchers=true` [#3805](https://github.com/rust-lang/rustfmt/issues/3805)
- Prevent panic when formatting trait declaration with non [Unicode Normalization Form] C (NFC) identifiers [#6069](https://github.com/rust-lang/rustfmt/issues/6069)
```rust
// The ó below is two codepoints, ASCII o followed by U+0301 COMBINING ACUTE ACCENT.
// It NFC-normalizes to ó, U+00F3 LATIN SMALL LETTER O WITH ACUTE.
trait Foó: Bar {}
```
- Ensure a space is added to a range expression, when the right hand side of the range expression is a binary expression that ends with a trailing period.
```rust
let range = 3. / 2. ..4.;
```
- When using `version=Two`, comments in match arms that contain `=>` no longer prevent formatting [#5998](https://github.com/rust-lang/rustfmt/issues/5998)
```rust
match a {
_ =>
// comment with =>
{
println!("A")
}
}
```
- Prevent panics when formatting input that contains the expanded form of `offset_of!` [#5885](https://github.com/rust-lang/rustfmt/issues/5885) [#6105](https://github.com/rust-lang/rustfmt/issues/6105)
-`hide_parse_errors` has been soft deprecated and it's been renamed to `show_parse_errors` [#5961](https://github.com/rust-lang/rustfmt/pull/5961).
- The diff output produced by `rustfmt --check` is more compatable with editors that support navigating directly to line numbers [#5971](https://github.com/rust-lang/rustfmt/pull/5971)
### Added
-`generated_marker_line_search_limit` is a new unstable configuration option that allows users to configure how many lines to search for an `@generated` marker when `format_generated_files=false` [#5658](https://github.com/rust-lang/rustfmt/issues/5658)
- Sometimes when `format_code_in_doc_comments=true` was set some line comments were converted to block comments [#5533](https://github.com/rust-lang/rustfmt/issues/5533)
- rustfmt will no longer remove the braces in match arms when the block has a labeled [#5676](https://github.com/rust-lang/rustfmt/issues/5676)
- Calling methods on float literals ending in `.` will now be wrapped in parenthesis. e.g. `0. .to_string()` will be formatted as `(0.).to_string()` [#5791](https://github.com/rust-lang/rustfmt/issues/5791)
- Formatting doc comment lines that start with `.` or `)` won't be treated as ordered markdown lists because `.` or `)` must be preceded by a number to start an ordered markdown list [#5835](https://github.com/rust-lang/rustfmt/pull/5835)
- Add parenthesis around closures when they're used as method receives, don't have a block body, and end with `.` [#4808](https://github.com/rust-lang/rustfmt/issues/4808)
```rust
fn main() {
|| (10.).method();
(|| ..).method();
(|| 1..).method();
}
```
- Prevent removing `for<T>` when using the [`#![feature(non_lifetime_binders)]`](https://github.com/rust-lang/rust/issues/108185) [#5721](https://github.com/rust-lang/rustfmt/issues/5721)
```rust
#![feature(non_lifetime_binders)]
#![allow(incomplete_features)]
trait Other<U:?Sized> {}
trait Trait<U>
where
for<T> U: Other<T> {}
```
- Fix various issues with comments in imports [#5852](https://github.com/rust-lang/rustfmt/issues/5852) [#4708](https://github.com/rust-lang/rustfmt/issues/4708) [#3984](https://github.com/rust-lang/rustfmt/issues/3984)
- When setting `version = Two` newlines between where clause bounds will be removed [#5655](https://github.com/rust-lang/rustfmt/issues/5655)
```rust
fn foo<T>(_: T)
where
T: std::fmt::Debug,
T: std::fmt::Display,
{
}
```
- Improve formatting of `let-else` statements that have leading attributes When setting `version = Two` [#5901](https://github.com/rust-lang/rustfmt/issues/5901)
- Prevent comment duplication in expressions wrapped in parenthesis. [#5871](https://github.com/rust-lang/rustfmt/issues/5871)
- Adjust the span derivation used when rewriting const generics. The incorrect span derivation lead to invalid code after reformatting. [#5935](https://github.com/rust-lang/rustfmt/issues/5935)
- Setting `trailing_semicolon = false` will only remove trailing `;` on the last expression in a block [#5797](https://github.com/rust-lang/rustfmt/issues/5797)
- Update the format of `cargo help fmt` to be more consistent with other standard commands [#5908](https://github.com/rust-lang/rustfmt/pull/5908)
### Added
- Users can now set `skip_macro_invocations` in `rustfmt.toml` [#5816](https://github.com/rust-lang/rustfmt/issues/5816)
- Adds initial support for formatting `let-chains`. **`let-chains` are still a nightly feature and their formatting is subject to change** [#5910](https://github.com/rust-lang/rustfmt/pull/5910). Formatting was implemented following the rules outlined in [rust-lang/rust#110568](https://github.com/rust-lang/rust/pull/110568)
- Support for formatting let-else statements [#5690]
- New config option, `single_line_let_else_max_width`, that allows users to configure the maximum length of single line `let-else` statements. `let-else` statements that otherwise meet the requirements to be formatted on a single line will have their divergent`else` block formatted over multiple lines if they exceed this length [#5684]
- When formatting doc comments with `wrap_comments = true` rustfmt will no longer wrap markdown tables [#4210](https://github.com/rust-lang/rustfmt/issues/4210)
- Properly handle wrapping comments that include a numbered list in markdown [#5416](https://github.com/rust-lang/rustfmt/issues/5416)
- rustfmt will no longer use shorthand initialization when rewriting a tuple struct even when `use_field_init_shorthand = true` as this leads to code that could no longer compile.
Take the following struct as an example `struct MyStruct(u64);`. rustfmt will no longer format `MyStruct { 0: 0 }` as `MyStruct { 0 }` [#5488](https://github.com/rust-lang/rustfmt/issues/5488)
- rustfmt no longer panics when formatting an empty code block in a doc comment with `format_code_in_doc_comments = true` [#5234](https://github.com/rust-lang/rustfmt/issues/5234). For example:
```rust
/// ```
///
/// ```
fn main() {}
```
- rustfmt no longer incorrectly duplicates the where clause bounds when using const expression in where clause bounds with feature `#![feature(generic_const_exprs)]` [#5691](https://github.com/rust-lang/rustfmt/issues/5691). e.g.:
```rust
struct S<constC:usize>
where
[(); { num_slots!(C) }]:, {
// code ...
}
```
- Prevent ICE when parsing invalid attributes in `cfg_if!` macros [#5728](https://github.com/rust-lang/rustfmt/issues/5728), [#5729](https://github.com/rust-lang/rustfmt/issues/5729)
- rustfmt no longer loses comments placed between a doc comment and generic params [#5320](https://github.com/rust-lang/rustfmt/issues/5320)
- Handle explicit discriminants in enums with comments present [#5686](https://github.com/rust-lang/rustfmt/issues/5686)
### Changed
- Users can now control whether rustc parser errors are displayed with color using rustfmt's `--color` option. To disable colored errors pass `--color=Never` to rustfmt [#5717](https://github.com/rust-lang/rustfmt/issues/5717)
### Added
- rustfmt now recognises `+` as the start of a markdown list, and won't incorrectly wrap sublists that begin with `+` when formatting doc comments with `wrap_comments = true` [#5560](https://github.com/rust-lang/rustfmt/pull/5560)
### Misc
- Update various dependencies, including `syn`, `cargo_metadata`, `env_logger`, and `toml`
- Resolve issue when comments are found within const generic defaults in unit structs [#5668](https://github.com/rust-lang/rustfmt/issues/5668)
- Resolve issue when block comments are found within trait generics [#5358](https://github.com/rust-lang/rustfmt/issues/5358)
- Correctly handle alignment of comments containing unicode characters [#5504](https://github.com/rust-lang/rustfmt/issues/5504)
- Properly indent a single generic bound that requires being written across multiple lines [#4689](https://github.com/rust-lang/rustfmt/issues/4689) (n.b. this change is version gated and will only appear when the `version` configuration option is set to `Two`)
### Changed
- Renamed `fn_args_layout` configuration option to `fn_params_layout` [#4149](https://github.com/rust-lang/rustfmt/issues/4149). Note that `fn_args_layout` has only been soft deprecated: `fn_args_layout` will continue to work without issue, but rustfmt will display a warning to encourage users to switch to the new name
### Added
- New configuration option (`skip_macro_invocations`)[https://rust-lang.github.io/rustfmt/?version=master&search=#skip_macro_invocations] [#5347](https://github.com/rust-lang/rustfmt/pull/5347) that can be used to globally define a single enumerated list of macro calls that rustfmt should skip formatting. rustfmt [currently also supports this via a custom tool attribute](https://github.com/rust-lang/rustfmt#tips), however, these cannot be used in all contexts because [custom inner attributes are unstable](https://github.com/rust-lang/rust/issues/54726)
### Misc
- rustfmt now internally supports the ability to have both stable and unstable variants of a configuration option [#5378](https://github.com/rust-lang/rustfmt/issues/5378). This ability will allow the rustfmt team to make certain configuration options available on stable toolchains more quickly because we no longer have to wait for _every_ variant to be stable-ready before stabilizing _any_ variant.
- **Build from source** - [Tag v1.5.2](https://github.com/rust-lang/rustfmt/tree/v1.5.2), see instructions for how to [install rustfmt from source][install-from-source]
**N.B** A bug was introduced in v1.5.0/nightly-2022-06-15 which modified formatting. If you happened to run rustfmt over your code with one of those ~10 nightlies it's possible you may have seen formatting changes, and you may see additional changes after this fix since that bug has now been reverted.
### Fixed
- Correct an issue introduced in v1.5.0 where formatting changes were unintentionally introduced in a few cases with a large/long construct in a right hand side position (e.g. a large chain on the RHS of a local/assignment statement)
-`cargo fmt --version` properly displays the version value again [#5395](https://github.com/rust-lang/rustfmt/issues/5395)
### Changed
- Properly sort imports containing raw identifiers [#3791](https://github.com/rust-lang/rustfmt/issues/3791) (note this is change version gated, and not applied by default)
### Added
- Add new configuration option, `doc_comment_code_block_width`, which allows for setting a shorter width limit to use for formatting code snippets in doc comments [#5384](https://github.com/rust-lang/rustfmt/issues/5384)
- **Build from source** - [Tag v1.5.1](https://github.com/rust-lang/rustfmt/tree/v1.5.1), see instructions for how to [install rustfmt from source][install-from-source]
- Simplify the rustfmt help text by eliding the full path to the rustfmt binary path from the usage string when running `rustfmt --help` [#5214](https://github.com/rust-lang/rustfmt/issues/5214)
- Bumped the version for several dependencies. Most notably `dirs``v2.0.1` -> `v4.0.0`. This changed the global user config directory on macOS from `$HOME/Library/Preferences` to `$HOME/Library/Application Support` [#5237](https://github.com/rust-lang/rustfmt/pull/5237)
- Maintain attributes on imports when `imports_granularity` is set to `Item` [#5030](https://github.com/rust-lang/rustfmt/issues/5030)
- Format empty trait definitions as a single line when both `empty_item_single_line` is enabled and `brace_style` is set to `AlwaysNextLine` [#5047](https://github.com/rust-lang/rustfmt/issues/5047)
- Don't change granularity of imports containing comments with `imports_granularity` if doing so could lose or misplace those comments [#5311](https://github.com/rust-lang/rustfmt/pull/5311)
- Prevent rustfmt from removing trailing comments at the end of files annotated with inner `#![rustfmt::skip]` attributes [#5033](https://github.com/rust-lang/rustfmt/issues/5033)
- Fixed various `error[internal]: left behind trailing whitespace"` issues:
- Remove trailing whitespace when formatting a where clause who's bounds have an empty right hand side [#5012](https://github.com/rust-lang/rustfmt/issues/5012) [#4850](https://github.com/rust-lang/rustfmt/issues/4850)
- Prevent rustfmt from adding an empty comment line when rewriting markdown lists at the start of doc comments. This issue was triggered when `wrap_comments=true` [#5088](https://github.com/rust-lang/rustfmt/issues/5088)
- Prevent adding a block indented newline before a function parameter with a complex type that was formatted over multiple lines [#5125](https://github.com/rust-lang/rustfmt/issues/5125)
- Fix various module resolution issues preventing rustfmt from finding modules that should be formatted:
- Handle external mods imported via external->inline load hierarchy [#5063](https://github.com/rust-lang/rustfmt/issues/5063)
- Resolve sub modules of integration tests [#5119](https://github.com/rust-lang/rustfmt/issues/5119)
- Module resolution will fallback to the current search directory if a relative directory search results in a `FileNotFound` error [#5198](https://github.com/rust-lang/rustfmt/issues/5198)
- Give users a clearer error message when resolving a module who's file path is ambiguous (e.g `x.rs` and `x/mod.rs`). Before users were given a `File not found` error message which was confusing [#5167](https://github.com/rust-lang/rustfmt/issues/5167)
- Fix various issues related to type aliases:
- Prevent rustfmt from adding `= impl` to associated types defined in macro bodies [#4823](https://github.com/rust-lang/rustfmt/issues/4823)
- Properly block indent type alias impl traits (TAITs) that wrap to the next line when `version=Two` is set. Before any trait bounds that wrapped to the next line would not be indented [#5027](https://github.com/rust-lang/rustfmt/issues/5027)
- Prevent rustfmt from adding an `impl Trait` definition into types [#5086](https://github.com/rust-lang/rustfmt/issues/5086)
- Fix cases where `normalize_comments=true` would de-normalizes some comments by changing inline comments into block comments [#4909](https://github.com/rust-lang/rustfmt/issues/4909)
- Prevent rustfmt from wrapping the content of markdown [reference-style links](https://www.markdownguide.org/basic-syntax/#reference-style-links) in doc comments [#5095](https://github.com/rust-lang/rustfmt/issues/5095) [#4933](https://github.com/rust-lang/rustfmt/issues/4933)
- Don't format files annotated with inner `#![rustfmt::skip]` attribute [PR #5094](https://github.com/rust-lang/rustfmt/pull/5094)
- Prevent duplicate comma when struct pattern ends with `..` and `trailing_comma=Always`. For example, `let Foo { a, .. } = b;` would become `let Foo { a,, .. } = b;` [#5066](https://github.com/rust-lang/rustfmt/issues/5066)
- Fix the order of `static` and `async` keywords when rewriting static async closures. The correct order is `static` and then `async` (e.g `static async || {}`) [#5149](https://github.com/rust-lang/rustfmt/issues/5149)
- Retain the fully qualified path segment when rewriting struct literals in expression position. Now `<Struct as Trait>::Type` is not rewritten as `Trait::Type` [#5151](https://github.com/rust-lang/rustfmt/issues/5151)
- Do not remove match arm braces from a match arm with a single `ast::ExprKind::Block` that has leading attributes. Removing the braces could lead to code that does not compile. Now rustfmt will leave the outer `{}` in place when formatting `=> {#[allow(unsafe_code)]unsafe {}}` [#4109](https://github.com/rust-lang/rustfmt/issues/4109)
- Backport json emitter and stdin changes [PR #5054](https://github.com/rust-lang/rustfmt/pull/5054)
- Make `--check` work when running rustfmt with input from stdin [PR #3896](https://github.com/rust-lang/rustfmt/pull/3896)
- Fix `--check` with the `--files-with-diff` flag [PR #3910](https://github.com/rust-lang/rustfmt/pull/3910)
- Produce valid JSON when using the JSON emitter [PR #3953](https://github.com/rust-lang/rustfmt/pull/3953)
- Fix newlines in JSON output [PR #4262](https://github.com/rust-lang/rustfmt/pull/4262)
- Use `<stdin>` when emitting stdin as filename [PR #4298](https://github.com/rust-lang/rustfmt/pull/4298)
- Always generate some output when formatting `@generated` files via stdin even when `format_generated_files=false`. Not producing output caused rust-analyzer to delete the file content [rust-lang/rust-analyzer](https://github.com/rust-lang/rust-analyzer/issues/11285) [#5172](https://github.com/rust-lang/rustfmt/issues/5172)
- Properly block indent multi-line comments in empty struct definitions. Previously, only the first comment line would be block indented. All other comment lines would be aligned with the struct definition [#4854](https://github.com/rust-lang/rustfmt/issues/4854)
- Prevent rustfmt from wrapping a comment at a byte position inside a non-ascii character when `wrap_comments=true`. This prevents rustfmt from panicking when breaking on the invalid position [#5023](https://github.com/rust-lang/rustfmt/issues/5023)
- Prevent rustfmt from removing commented out trailing separators (e.g commas) when rewriting lists. For example, remove the comma from a comment like this `// ...,` would lead to a scenario where the entire list could not be rewritten because the content of the comment changed [#5042](https://github.com/rust-lang/rustfmt/issues/5042)
- Fix panic when `import_granularity` was set to `Module`, `One`, or `Crate` and the import use declaration contained an alias `use crate a::b as b1` [#5131](https://github.com/rust-lang/rustfmt/issues/5131)
- Add a newline between generic parameters and their doc comments to prevent the generic parameters from being merged into their doc comments [#5122](https://github.com/rust-lang/rustfmt/issues/5122)
- Fixes indentation issue where string literals manually broken with line continuation characters (`\`) would be incorrectly indented in macro definitions when setting `format_strings=true`[#4036](https://github.com/rust-lang/rustfmt/issues/4036)
- Properly wrap and format long markdown block quotes when `wrap_comments=true` [#5157](https://github.com/rust-lang/rustfmt/issues/5157)
- Prevent rustfmt from wrapping markdown headers even when `wrap_comments=true`. Wrapping the markdown headers would prevent them from being properly rendered with rustdoc [#5238](https://github.com/rust-lang/rustfmt/issues/5238)
- Prevent rustfmt from removing commas between struct fields when those fields were also separated by an empty line [#4791](https://github.com/rust-lang/rustfmt/issues/4791) [#4928](https://github.com/rust-lang/rustfmt/issues/4928)
- Fix compiler error caused when formatting imports with `imports_granularity=Module` and a path containing `self`. Given the following import `use crate::lexer::{self, tokens::TokenData};`, rustfmt would transform the `self` import into `use crate::lexer::self;`. Now rustfmt produces `use crate::lexer::{self};` [#4681](https://github.com/rust-lang/rustfmt/issues/4681)
- Prevent rustfmt from breaking long type links in doc comments on namespace qualifiers (`::`) when `wrap_comments=true`. Breaking these long type links over multiple lines prevented them from being properly rendered in rustdoc [#5260](https://github.com/rust-lang/rustfmt/issues/5260)
- Correctly find the start of struct bodies after any generic `const` parameters. Naively searching for an opening `{` lead to issues since generic `const` parameters are also defined with `{}` (e.g. `struct Example<const N: usize = { 1048576 }> {}`) [#5273](https://github.com/rust-lang/rustfmt/issues/5273)
- Prevent rustfmt from merging derives when using inner or outer `rustfmt::skip::attributes` attributes. For example, `#[rustfmt::skip::attributes(derive)]` [#5270](https://github.com/rust-lang/rustfmt/issues/5270)
- Retain trailing `;` when rewriting macro calls in extern blocks. For example, `extern "C" { x!(-); }`[#5281](https://github.com/rust-lang/rustfmt/issues/5281)
- Add a newline when formatting struct fields preceded by both doc comments and inline comments to prevent the field from being merged into the inline comment. This was not an issue when a struct was preceded by just a doc comment or just an inline comment [#5215](https://github.com/rust-lang/rustfmt/issues/5215)
### Added
- Added `One` as a new [group_imports](https://rust-lang.github.io/rustfmt/?version=v1.4.38&search=#group_imports) option to create a single group for all imports [PR #4966](https://github.com/rust-lang/rustfmt/pull/4966)
- Add [short_array_element_width_threshold](https://rust-lang.github.io/rustfmt/?version=v1.4.38&search=#short_array_element_width_threshold) config option to give users more control over when `Mixed` list formatting is used [PR #5228](https://github.com/rust-lang/rustfmt/pull/5228)
- Improved performance when formatting large and deeply nested expression trees, often found in generated code, which have many expressions that exceed `max_width` [#5128](https://github.com/rust-lang/rustfmt/issues/5128), [#4867](https://github.com/rust-lang/rustfmt/issues/4867), [#4476](https://github.com/rust-lang/rustfmt/issues/4476), [#5139](https://github.com/rust-lang/rustfmt/pull/5139)
- **Build from source** - [Tag v1.5.0](https://github.com/rust-lang/rustfmt/tree/v1.5.0), see instructions for how to [install rustfmt from source][install-from-source]
- Switched from `rustc-ap-*` crates to `rustc_private` for consumption model of rustc internals
-`annotate-snippets` updated to v0.8 [PR #4762](https://github.com/rust-lang/rustfmt/pull/4762)
- Greatly improved the performance of `cargo fmt` in large workspaces utilizing the `--all` flag by updating to a newer version of `cargo_metadata` that leverages updated `cargo` output from v1.51+ [PR #4997](https://github.com/rust-lang/rustfmt/pull/4997)
- Improved formatting of long slice patterns [#4530](https://github.com/rust-lang/rustfmt/issues/4530)
- **Note you must have `version = Two` in your configuration to take advantage of the new formatting**
- Various improvements to the configuration documentation website [https://rust-lang.github.io/rustfmt/?version=v1.4.38]([https://rust-lang.github.io/rustfmt/?version=v1.4.38])
- Addressed various clippy and rustc warnings
### Fixed
- Resolved issue where specious whitespace would be inserted when a block style comment was terminated within string literal processing [#4312](https://github.com/rust-lang/rustfmt/issues/4312)
- Nested out-of-line mods are again parsed and formatted [#4874](https://github.com/rust-lang/rustfmt/issues/4874)
- Accepts `2021` for edition value from rustfmt command line [PR #4847](https://github.com/rust-lang/rustfmt/pull/4847)
- Unstable command line options are no longer displayed in `--help` text on stable [PR #4798](https://github.com/rust-lang/rustfmt/issues/4798)
- Stopped panicking on patterns in match arms which start with non-ascii characters [#4868](https://github.com/rust-lang/rustfmt/issues/4868)
- Stopped stripping defaults on const params [#4816](https://github.com/rust-lang/rustfmt/issues/4816)
- Fixed issue with dropped content with GAT aliases with self bounds in impls [#4911](https://github.com/rust-lang/rustfmt/issues/4911)
- Stopped removing generic args on associated type constraints [#4943](https://github.com/rust-lang/rustfmt/issues/4943)
- Stopped dropping visibility on certain trait and impl items [#4960](https://github.com/rust-lang/rustfmt/issues/4960)
- Fixed dropping of qualified paths in struct patterns [#4908](https://github.com/rust-lang/rustfmt/issues/4908) and [#5005](https://github.com/rust-lang/rustfmt/issues/5005)
- Fixed bug in line width calculation that was causing specious formatting of certain patterns [#4031](https://github.com/rust-lang/rustfmt/issues/4031)
- **Note that this bug fix may cause observable formatting changes in cases where code had been formatted with prior versions of rustfmt that contained the bug**
- Fixed bug where rustfmt would drop parameter attributes if they were too long in certain cases [#4579](https://github.com/rust-lang/rustfmt/issues/4579)
- Resolved idempotency issue with extern body elements [#4963](https://github.com/rust-lang/rustfmt/issues/4963)
- rustfmt will now handle doc-style comments on function parameters, since they could appear with certain macro usage patterns even though it's generally invalid syntax [#4936](https://github.com/rust-lang/rustfmt/issues/4936)
- Fixed bug in `match_block_trailing_comma` where commas were not added to the blocks of bodies whose arm had a guard that did not fit on the same line as the pattern [#4998](https://github.com/rust-lang/rustfmt/pull/4998)
- Fixed bug in cases where derive attributes started with a block style comment [#4984](https://github.com/rust-lang/rustfmt/issues/4984)
- Fixed issue where the struct rest could be lost when `struct_field_align_threshold` was enabled [#4926](https://github.com/rust-lang/rustfmt/issues/4926)
- Handles cases where certain control flow type expressions have comments between patterns/keywords and the pattern ident contains the keyword [#5009](https://github.com/rust-lang/rustfmt/issues/5009)
- Handles tuple structs that have explicit visibilities and start with a block style comment [#5011](https://github.com/rust-lang/rustfmt/issues/5011)
- Handles leading line-style comments in certain types of macro calls [#4615](https://github.com/rust-lang/rustfmt/issues/4615)
### Added
- Granular width heuristic options made available for user control [PR #4782](https://github.com/rust-lang/rustfmt/pull/4782). This includes the following:
Note this hit the rustup distributions prior to the v1.4.38 release as part of an out-of-cycle updates, but is listed in this version because the feature was not in the other v1.4.37 releases. See also the `use_small_heuristics` section on the configuration site for more information
- New `One` variant added to `imports_granularity` configuration option which can be used to reformat all imports into a single use statement [#4669](https://github.com/rust-lang/rustfmt/issues/4669)
- rustfmt will now skip files that are annotated with `@generated` at the top of the file [#3958](https://github.com/rust-lang/rustfmt/issues/3958)
- New configuration option `hex_literal_case` that allows user to control the casing utilized for hex literals [PR #4903](https://github.com/rust-lang/rustfmt/pull/4903)
See the section on the configuration site for more information
-`cargo fmt` now directly supports the `--check` flag, which means it's now possible to run `cargo fmt --check` instead of the more verbose `cargo fmt -- --check` [#3888](https://github.com/rust-lang/rustfmt/issues/3888)
- **Build from source** - [Tag v1.4.38](https://github.com/rust-lang/rustfmt/tree/v1.4.38), see instructions for how to [install rustfmt from source][install-from-source]
- Resolve idempotence issue related to indentation of macro defs that contain or-patterns with inner comments ([#4603](https://github.com/rust-lang/rustfmt/issues/4603))
- **Build from source** - [Tag v1.4.37](https://github.com/rust-lang/rustfmt/tree/v1.4.37), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.36](https://github.com/rust-lang/rustfmt/tree/v1.4.36), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.35](https://github.com/rust-lang/rustfmt/tree/v1.4.35), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.34](https://github.com/rust-lang/rustfmt/tree/v1.4.34), see instructions for how to [install rustfmt from source][install-from-source]
-`merge_imports` configuration has been deprecated in favor of the new `imports_granularity` option. Any existing usage of `merge_imports` will be automatically mapped to the corresponding value on `imports_granularity` with a warning message printed to encourage users to update their config files.
### Added
- New `imports_granularity` option has been added which succeeds `merge_imports`. This new option supports several additional variants which allow users to merge imports at different levels (crate or module), and even flatten imports to have a single use statement per item. ([PR #4634](https://github.com/rust-lang/rustfmt/pull/4634), [PR #4639](https://github.com/rust-lang/rustfmt/pull/4639))
See the section on the configuration site for more information
- Idempotence issue on blocks containing only empty statements ([#4627](https://github.com/rust-lang/rustfmt/issues/4627) and [#3868](https://github.com/rust-lang/rustfmt/issues/3868))
- Fix issue with semicolon placement on required functions that have a trailing comment that ends in a line-style comment before the semicolon ([#4646](https://github.com/rust-lang/rustfmt/issues/4646))
- Avoid shared interned cfg_if symbol since rustfmt can re-initialize the rustc_ast globals on multiple inputs ([#4656](https://github.com/rust-lang/rustfmt/issues/4656))
- **Build from source** - [Tag v1.4.33](https://github.com/rust-lang/rustfmt/tree/v1.4.33), see instructions for how to [install rustfmt from source][install-from-source]
- Indentation now correct on first bound in cases where the generic bounds are multiline formatted and the first bound itself is multiline formatted ([#4636](https://github.com/rust-lang/rustfmt/issues/4636))
- **Build from source** - [Tag v1.4.32](https://github.com/rust-lang/rustfmt/tree/v1.4.32), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.31](https://github.com/rust-lang/rustfmt/tree/v1.4.31), see instructions for how to [install rustfmt from source][install-from-source]
- Last character in derive no longer erroneously stripped when `indent_style` is overridden to `Visual`. ([#4584](https://github.com/rust-lang/rustfmt/issues/4584))
- Brace wrapping of closure bodies maintained in cases where the closure has an explicit return type and the body consists of a single expression statement. ([#4577](https://github.com/rust-lang/rustfmt/issues/4577))
- No more panics on invalid code with `err` and `typeof` types ([#4357](https://github.com/rust-lang/rustfmt/issues/4357), [#4586](https://github.com/rust-lang/rustfmt/issues/4586))
- **Build from source** - [Tag v1.4.30](https://github.com/rust-lang/rustfmt/tree/v1.4.30), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.29](https://github.com/rust-lang/rustfmt/tree/v1.4.29), see instructions for how to [install rustfmt from source][install-from-source]
- In the event of an invalid inner attribute on a `cfg_if` condition, rustfmt will now attempt to continue and format the imported modules. Previously rustfmt would emit the parser error about an inner attribute being invalid in this position, but for rustfmt's purposes the invalid attribute doesn't prevent nor impact module formatting.
### Added
- [`group_imports`][group-imports-config-docs] - a new configuration option that allows users to control the strategy used for grouping imports ([#4107](https://github.com/rust-lang/rustfmt/issues/4107))
- Formatting of malformed derived attributes is no longer butchered. ([#3898](https://github.com/rust-lang/rustfmt/issues/3898), [#4029](https://github.com/rust-lang/rustfmt/issues/4029), [#4115](https://github.com/rust-lang/rustfmt/issues/4115), [#4545](https://github.com/rust-lang/rustfmt/issues/4545))
- Correct indentation used in macro branches when `hard_tabs` is enabled. ([#4152](https://github.com/rust-lang/rustfmt/issues/4152))
- Comments between the visibility modifier and item name are no longer dropped. ([#2781](https://github.com/rust-lang/rustfmt/issues/2781))
- Comments preceding the assignment operator in type aliases are no longer dropped. ([#4244](https://github.com/rust-lang/rustfmt/issues/4244))
- Comments between {`&` operator, lifetime, `mut` kw, type} are no longer dropped. ([#4245](https://github.com/rust-lang/rustfmt/issues/4245))
- Comments between type bounds are no longer dropped. ([#4243](https://github.com/rust-lang/rustfmt/issues/4243))
- Function headers are no longer dropped on foreign function items. ([#4288](https://github.com/rust-lang/rustfmt/issues/4288))
- Foreign function blocks are no longer dropped. ([#4313](https://github.com/rust-lang/rustfmt/issues/4313))
-`where_single_line` is no longer incorrectly applied to multiline function signatures that have no `where` clause. ([#4547](https://github.com/rust-lang/rustfmt/issues/4547))
-`matches!` expressions with multiple patterns and a destructure pattern are now able to be formatted. ([#4512](https://github.com/rust-lang/rustfmt/issues/4512))
- **Build from source** - [Tag v1.4.28](https://github.com/rust-lang/rustfmt/tree/v1.4.28), see instructions for how to [install rustfmt from source][install-from-source]
- Leading comments in an extern block are no longer dropped (a bug that exists in v1.4.26). ([#4528](https://github.com/rust-lang/rustfmt/issues/4528))
- **Build from source** - [Tag v1.4.27](https://github.com/rust-lang/rustfmt/tree/v1.4.27), see instructions for how to [install rustfmt from source][install-from-source]
- Original comment indentation for trailing comments within an `if` is now taken into account when determining the indentation level to use for the trailing comment in formatted code. This does not modify any existing code formatted with rustfmt; it simply gives the programmer discretion to specify whether the comment is associated to the `else` block, or if the trailing comment is just a member of the `if` block. ([#1575](https://github.com/rust-lang/rustfmt/issues/1575), [#4120](https://github.com/rust-lang/rustfmt/issues/4120), [#4506](https://github.com/rust-lang/rustfmt/issues/4506))
In this example the `// else comment` refers to the `else`:
```rust
// if comment
if cond {
"if"
// else comment
} else {
"else"
}
```
Whereas in this case the `// continue` comments are members of their respective blocks and do not refer to the `else` below.
```rust
if toks.eat_token(Token::Word("modify"))? && toks.eat_token(Token::Word("labels"))? {
if toks.eat_token(Token::Colon)? {
// ate the token
} else if toks.eat_token(Token::Word("to"))? {
// optionally eat the colon after to, e.g.:
// @rustbot modify labels to: -S-waiting-on-author, +S-waiting-on-review
toks.eat_token(Token::Colon)?;
} else {
// It's okay if there's no to or colon, we can just eat labels
// afterwards.
}
1 + 2;
// continue
} else if toks.eat_token(Token::Word("label"))? {
// continue
} else {
return Ok(None);
}
```
### Fixed
- Formatting of empty blocks with attributes which only contained comments is no longer butchered.([#4475](https://github.com/rust-lang/rustfmt/issues/4475), [#4467](https://github.com/rust-lang/rustfmt/issues/4467), [#4452](https://github.com/rust-lang/rustfmt/issues/4452#issuecomment-705886282), [#4522](https://github.com/rust-lang/rustfmt/issues/4522))
- Indentation of trailing comments in non-empty extern blocks is now correct. ([#4120](https://github.com/rust-lang/rustfmt/issues/4120#issuecomment-696491872))
- **Build from source** - [Tag v1.4.26](https://github.com/rust-lang/rustfmt/tree/v1.4.26), see instructions for how to [install rustfmt from source][install-from-source]
- Semicolons are no longer automatically inserted on trailing expressions in macro definition arms ([#4507](https://github.com/rust-lang/rustfmt/pull/4507)). This gives the programmer control and discretion over whether there should be semicolons in these scenarios so that potential expansion issues can be avoided.
- **Build from source** - [Tag v1.4.25](https://github.com/rust-lang/rustfmt/tree/v1.4.25), see instructions for how to [install rustfmt from source][install-from-source]
- Block wrapped match arm bodies containing a single macro call expression are no longer flattened ([#4496](https://github.com/rust-lang/rustfmt/pull/4496)). This allows programmer discretion so that the block wrapping can be preserved in cases where needed to prevent issues in expansion, such as with trailing semicolons, and aligns with updated [Style Guide guidance](https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/expressions.md#macro-call-expressions) for such scenarios.
### Fixed
- Remove useless `deprecated` attribute on a trait impl block in the rustfmt lib, as these now trigger errors ([rust-lang/rust/#78626](https://github.com/rust-lang/rust/pull/78626))
- **Build from source** - [Tag v1.4.24](https://github.com/rust-lang/rustfmt/tree/v1.4.24), see instructions for how to [install rustfmt from source][install-from-source]
- **Build from source** - [Tag v1.4.23](https://github.com/rust-lang/rustfmt/tree/v1.4.23), see instructions for how to [install rustfmt from source][install-from-source]
- Add `inline_attribute_width` configuration option to write an item and its attribute on the same line if their combined width is below a threshold #3409
- Support `const` generics f0c861b
- Support path clarity module #3448
### Changed
- Align loop and while formatting 7d9a2ef
- Support `EmitMode::ModifiedLines` with stdin input #3424
- Update `rustc-ap-*` crates to 407.0.0
- Remove trailing whitespaces in missing spans 2d5bc69
### Fixed
- Do not remove comment in the case of no arg 8e3ef3e
- Fix `Ident of macro+ident gets duplicated` error 40ff078
- Format the if expression at the end of the block in a single line 5f3dfe6
- Add a [section](https://github.com/rust-lang/rustfmt/blob/ae331be/Contributing.md#version-gate-formatting-changes) to the Contributing.md file about version-gating formatting changes 36e2cb0
- Allow specifying package with `-p` CLI option a8d2591
- Support `rustfmt::skip` on imports #3289
- Support global `rustfmt.toml` to be written in user config directory #3280
- Format visibility on trait alias 96a3df3
### Changed
- Do not modify original source code inside macro call #3260
- Recognize strings inside comments in order to avoid indenting them baa62c6
- Use Unicode-standard char width to wrap comments or strings a01990c
- Change new line point in the case of no args #3294
- Use the same formatting rule between functions and macros #3298
- Update rustc-ap-rustc_target to 366.0.0, rustc-ap-syntax to 366.0.0, and rustc-ap-syntax_pos to 366.0.0
### Fixed
- rewrite_comment: fix block fallback when failing to rewrite an itemized block ab7f4e1
- Catch possible tokenizer panics #3240
- Fix macro indentation on Windows #3266
- Fix shape when formatting return or break expr on statement position #3259
- rewrite_comment: fix block fallback when failing to rewrite an itemized block
- Keep leading double-colon to respect the 2018 edition of rust's paths a2bfc02
- Fix glob and nested global imports 2125ad2
- Do not force trailing comma when using mixed layout #3306
- Prioritize `single_line_fn` and `empty_item_single_line` over `brace_style`#3308
- Fix `internal error: left behind trailing whitespace` with long lines c2534f5
- Fix attribute duplication #3325
- Fix formatting of strings within a macro 813aa79
- Handle a macro argument with a single keyword 9a7ea6a
