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 and dart 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. The dart 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 that dart 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 the DartFormatter() 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 in DartFormatter.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 when that style becomes available.
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 up 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 like dart analyze and dart 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 separate dartfmt 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 and if you passed no arguments at all, it silently sat there waiting for input on stdin. When we added dart 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 ran dart pub global activate dart_style, this would give you a dartfmt (and dartformat) executable with the old CLI options. Now that almost everyone is using dart 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 the dart 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 parses stdin using the latest supported language version.
Apply class modifiers to API classes. The dart_style package exposes only a few classes in its public API: DartFormatter, SourceCode, FormatterException, and UnexpectedOutputException. None were ever intended to be extended or implemented. They are now all marked final to make that intention explicit.
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.// 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).this. or super. (#1321).as and if clauses (#1544).package:analyzer >=6.5.0 <7.0.0.3.3 to parse so that code with extension types can be formatted.macro modifier when the macros experiment flag is passed.tall-style experiment flag to enable the in-progress unstable new formatting style (#1253).inline class since that syntax has changed.--enable-experiment command-line option to enable language experiments. The library API also supports this with DartFormatter.experimentFlags.. following a record literal (#1213).package:analyzer >=5.12.0 <7.0.0.? on nullable empty record types (#1224).--fix and related options in --help. The options are still there and supported, but are no longer shown by default. Eventually, we would like all users to move to using dart fix instead of dart format --fix.|| pattern operands in switch expression cases.sealed, interface, and final keywords on mixin declarations. The proposal was updated to no longer support them.base, final, interface, mixin, and sealed.inline class declarations.sync* and async* functions with => bodies.< in collection literals._visitFunctionOrMethodDeclaration instead of dynamically typed.( significant (sdk#50769).package:analyzer ^5.7.0.{ or [ and a subsequent comment. It used to do this before the { in type bodies, but not switch bodies, optional parameter sections, or named parameter sections.package:analyzer >=4.4.0 <6.0.0.package:analyzer.package:analyzer version 2.6.0.NamedType instead of TypeName./* */ comments (#837).FormatCommand when formatting stdin (#1035).package:analyzer.>>> and >>>= operators (#992).required (#1010).FormatCommand.run() now returns the value set in exitCode during formatting.package:analyzer.package:args and package:pub_semver.? in initializing formal function-typed parameters (#960).?:) when they are nested (#927).external and abstract fields and variables (#946).--stdin-name=<stdin>.--fix-single-cascade-statements.var in --fix-function-typedefs (#826).?.[] to ?[].package:analyzer 0.39.0.? in types.late modifier.required modifier.. when the target is parenthesized (#704).package:analyzer 0.38.0.package:analyzer 0.37.0.=> functions.Properly format trailing commas in assertions.
Improve indentation of adjacent strings. This fixes a regression introduced in 1.2.5 and hopefully makes adjacent strings generally look better.
Adjacent strings in argument lists now format the same regardless of whether the argument list contains a trailing comma. The rule is that if the argument list contains no other strings, then the adjacent strings do not get extra indentation. This keeps them lined up when doing so is unlikely to be confused as showing separate independent string arguments.
Previously, adjacent strings were never indented in argument lists without a trailing comma and always in argument lists that did. With this change, adjacent strings are still always indented in collection literals because readers are likely to interpret a series of unindented lines there as showing separate collection elements.
if and for elements inside collections (#779).package:analyzer constraint to '>=0.33.0 <0.36.0'.--fix-function-typedefs to convert the old typedef syntax for function types to the new preferred syntax.--stdin-name to specify name shown when reading from stdin (#739).--fix-doc-comments to turn /** ... */ doc comments into /// (#730).const in all metadata annotations with --fix-optional-const` (#720).Preserve whitespace in multi-line strings inside string interpolations (#711). Note! This bug means that dart_style 1.1.2 may make semantics changes to your strings. You should avoid that version and use 1.1.3.
Set max SDK version to <3.0.0, and adjusted other dependencies.
: to = as the named parameter default value separator.new keywords.const keywords.package:analyzer.. if the target expression is an argument list with a trailing comma (#548, #665).new/const (#652).pkg/args.pkg/analyzer.- and -- (#170).=> bodies (#584).< when a collection is in statement position (#589).covariant modifier on methods.is and as expressions.--set-exit-if-changed to set the exit code on a change (#365).--version command line argument (#240).. in a method chain if the target splits (#255).=> bodies (#434.if statements without curly bodies better (#448).get and set (#462).--indent to specify leading indent (#464).for fully split if initializers or updaters do (#375, #377).deferred (#381).as and is expressions (#384).?., ??, and ??=) (#385).BREAKING: The indent argument to new DartFormatter() is now a number of spaces, not indentation levels.
This version introduces a new n-way constraint system replacing the previous binary constraints. It‘s mostly an internal change, but allows us to fix a number of bugs that the old solver couldn’t express solutions to.
In particular, it forces argument and parameter lists to go one-per-line if they don't all fit in two lines. And it allows function and collection literals inside expressions to indent like expressions in some contexts. (#78, #97, #101, #123, #139, #141, #142, #143, et. al.)
Indent cascades more deeply when the receiver is a method call (#137).
Preserve newlines in collections containing line comments (#139).
Allow multiple variable declarations on one line if they fit (#155).
Prefer splitting at “.” on non-identifier method targets (#161).
Enforce a blank line before and after classes (#168).
More precisely control newlines between declarations (#173).
Preserve mandatory newlines in inline block comments (#178).
Splitting inside type parameter and type argument lists (#184).
Nest blocks deeper inside a wrapped conditional operator (#186).
Split named arguments if the positional arguments split (#189).
Re-indent line doc comments even if they are flush left (#192).
Nest cascades like expressions (#200, #203, #205, #221, #236).
Prefer splitting after => over other options (#217).
Nested non-empty collections force surrounding ones to split (#223).
Allow splitting inside with and implements clauses (#228, #259).
Allow splitting after = in a constructor initializer (#242).
If a => function's parameters split, split after the => too (#250).
Allow splitting between successive index operators (#256).
Correctly indent wrapped constructor initializers (#257).
Set failure exit code for malformed input when reading from stdin (#359).
Do not nest blocks inside single-argument function and method calls.
Do nest blocks inside => functions.
test package runner internally.analyzer and args packages.dartformat to dartfmt.--dry-run option to show files that need formatting (#67).await for statements (#154).- calls (#170).-t flag to preserve compatibility with old formatter (#166).--machine flag for machine-readable output (#164).