Releases: dart-lang/dart_style
package:dart_style v3.0.1
- Handle trailing commas in for-loop updaters (#1354).
- Format
||
patterns like fallthrough cases in switch expressions (#1602). - Handle comments and metadata before variables more gracefully (#1604).
- Ensure comment formatting is idempotent (#1606).
- Better indentation of leading comments on property accesses in binary operator
operands (#1611). - Don't crash on doc comments in local variable declarations (#1621).
package:dart_style v3.0.0
This is a large change. Under the hood, the formatter was almost completely
rewritten, with the codebase now containing both the old and new
implementations. The old formatter exists to support the older "short" style
and the new code implements the new "tall" style.
The formatter uses the language version of the formatted code to determine
which style you get. If the language version is 3.6 or lower, the code is
formatted with the old style. If 3.7 or later, you get the new tall style. You
typically control the language version by setting a min SDK constraint in your
package's pubspec.
In addition to the new formatting style, a number of other API and CLI changes
are included, some of them breaking:
-
Support project-wide page width configuration. By long request, you can
now configure your preferred formatting page width on a project-wide basis.
When formatting files, the formatter will look in the file's directory and
any surrounding directories for ananalysis_options.yaml
file. If it finds
one, it looks for the following YAML:formatter: page_width: 123
If it finds a
formatter
key containing a map with apage_width
key whose
value is an integer, then that is the page width that the file is formatted
using. Since the formatter will walk the surrounding directories until it
finds ananalysis_options.yaml
file, this can be used to globally set the
page width for an entire directory, package, or even collection of packages. -
Support overriding the page width for a single file. In code formatted
using the new tall style, you can use a special marker comment to control the
page width that it's formatted using:// dart format width=30 main() { someExpression + thatSplitsAt30; }
This comment must appear before any code in the file and must match that
format exactly. The width set by the comment overrides the width set by any
surroundinganalysis_options.yaml
file.This feature is mainly for code generators that generate and immediately
format code but don't know about any surroundinganalysis_options.yaml
that might be configuring the page width. By inserting this comment in the
generated code before formatting, it ensures that the code generator's
behavior matches the behavior ofdart format
.End users should mostly use
analysis_options.yaml
for configuring their
preferred page width (or do nothing and use the default page width of 80). -
Support opting out a region of code from formatting. In code formatted
using the new tall style, you can use a pair of special marker comments to
opt a region of code out of automated formatting:main() { this.isFormatted(); // dart format off no + formatting + here; // dart format on formatting.isBackOnHere(); }
The comments must be exactly
// dart format off
and// dart format on
.
A file may have multiple regions, but they can't overlap or nest.This can be useful for highly structured data where custom layout can help
a reader understand the data, like large lists of numbers. -
Remove support for fixes and
--fix
. The tools that come with the Dart
SDK provide two ways to apply automated changes to code:dart format --fix
anddart fix
. The former is older and used to be faster. But it can only
apply a few fixes and hasn't been maintained in many years. Thedart fix
command is actively maintained, can apply all of the fixes that
dart format --fix
could apply and many many more.In order to avoid duplicate engineering effort, we decided to consolidate on
dart fix
as the one way to make automated changes that go beyond the simple
formatting and style changes thatdart format
applies.The ability to apply fixes is also removed from the
DartFormatter()
library
API. -
Make the language version parameter to
DartFormatter()
mandatory. This
way, the formatter always knows what language version the input is intended
to be treated as. Note that a// @dart=
language version comment, if
present, overrides the specified language version. You can think of the
version passed to theDartFormatter()
constructor as a "default" language
version which the file's contents may then override.If you don't particularly care about the version of what you're formatting,
you can pass inDartFormatter.latestLanguageVersion
to unconditionally get
the latest language version that the formatter supports. Note that doing so
means you will also implicitly opt into the new tall style.This change only affects the library API. When using the formatter from the
command line, you can use--language-version=
to specify a language version
or pass--language-version=latest
to use the latest supported version. If
omitted, the formatter will look in the surrounding directories for a package
config file and infer the language version for the package from that, similar
to how other Dart tools behave likedart analyze
anddart run
. -
Remove the old formatter executables and CLI options. Before the
dart format
command was added to the core Dart SDK, users accessed the
formatter by running a separatedartfmt
executable that was included with
the Dart SDK. That executable had a different CLI interface. For example, you
had to pass-w
to get it to overwrite files. When we addeddart format
,
we took that opportunity to revamp the CLI options.However, the dart_style package still exposed an executable with the old CLI.
If you randart pub global activate dart_style
, this would give you a
dartfmt
(anddartformat
) executable with the old CLI options. Now that
almost everyone is usingdart format
, we have removed the old CLI and the
old package executables.You can still run the formatter on the CLI through the package (for example,
if you want to use a particular version of dart_style instead of the one
bundled with your Dart SDK). But it now uses the exact same CLI options and
arguments as thedart format
command. You can invoke it with
dart run dart_style:format <args...>
. -
Treat the
--stdin-name
name as a path when inferring language version.
When reading input on stdin, the formatter still needs to know what language
version to parse the code as. If the--stdin-name
option is set, then that
is treated as a file path and the formatter looks for a package config
surrounding that file path to infer the language version from.If you don't want that behavior, pass in an explicit language version using
--language-version=
, or use--language-version=latest
to parse the input
using the latest language version supported by the formatter.If
--stdin-name
and--language-version
are both omitted, then the
formatter parses stdin using the latest supported language version. -
Rename the
--line-length
option to--page-width
. This is consistent
with the public API, internal implementation, and docs, which all use "page
width" to refer to the limit that the formatter tries to fit code into.The
--line-length
name is still supported for backwards compatibility, but
may be removed at some point in the future. You're encouraged to move to
--page-width
. Use of this option (however it's named) is rare, and will
likely be even rarer now that project-wide configuration is supported, so
this shouldn't affect many users. -
Apply class modifiers to API classes. The dart_style package exposes only
a few classes in its public API:DartFormatter
,SourceCode
,
FormatterException
, andUnexpectedOutputException
. None were ever
intended to be extended or implemented. They are now all markedfinal
to
make that intention explicit. -
Require
package:analyzer
>=6.5.0 <8.0.0
.
package:dart_style v2.3.7
- Allow passing a language version to
DartFomatter()
. Formatted code will be
parsed at that version. If omitted, defaults to the latest version. In a
future release, this parameter will become required. - Allow opting out of formatting for a region of code using
// dart format off
and// dart format on
comments. Note: This only works using the new tall
style and requires passing the--enable-experiment=tall-style
experiment
flag (#361). - Preserve type parameters on old-style function-typed formals that also use
this.
orsuper.
(#1321). - Correctly format imports with both
as
andif
clauses (#1544). - Remove temporary work around for analyzer 6.2.0 from dart_style 2.3.6.
- Require
package:analyzer
>=6.5.0 <7.0.0
.
package:dart_style v2.3.6
- Fix compile error when using dart_style with analyzer 6.2.0.
package:dart_style v2.3.5
- Ensure switch expressions containing line comments split (#1404).
- Use language version
3.3
to parse so that code with extension types can be
formatted. - Support formatting the
macro
modifier when themacros
experiment flag
is passed.
package:dart_style v2.3.4
package:dart_style v2.3.2
- Don't indent parameters that have metadata annotations. Instead, align them
with the metadata and other parameters. - Allow metadata annotations on parameters to split independently of annotations
on other parameters (#1212). - Don't split before
.
following a record literal (#1213). - Don't force split on a line comment before a switch expression case (#1215).
- Require
package:analyzer
>=5.12.0 <7.0.0
. - Preserve
?
on nullable empty record types (#1224).