Update dartfmt to 1.0.0

CHANGELOG.md

 ## 1.23.0
 
 ### Language
 * Allow using URI strings in `part of` declarations to refer to the
   importing library.
 
 ### Core library changes
 
 * `dart:core`
   * Added `Uri.isScheme` function to check the scheme of a URI.
     Example: `uri.isScheme("http")`. Ignores case when comparing.
   * Make `UriData.parse` validate its input better.
     If the data is base-64 encoded, the data is normalized wrt.
     alphabet and padding, and it contains invalid base-64 data,
     parsing fails. Also normalizes non-base-64 data.
 * `dart:io`
   * Added functions `File.lastAccessed`, `File.lastAccessedSync`,
     `File.setLastModified`, `File.setLastModifiedSync`, `File.setLastAccessed`,
     and `File.setLastAccessedSync`.
   * Added `{Stdin,Stdout}.supportsAnsiEscapes`.
 
 ### Dart VM
+
 * Calls to `print()` and `Stdout.write*()` now correctly print unicode
   characters to the console on Windows. Calls to `Stdout.add*()` behave as
   before.
 
 ### Tool changes
 
 * Analysis
   * `dartanalyzer` now follows the same rules as the analysis server to find
     an analysis options file, stopping when an analysis options file is found:
     * Search up the directory hierarchy looking for an analysis options file.
-    * If analyzing a project referencing the [Flutter](https://flutter.io/) 
+    * If analyzing a project referencing the [Flutter](https://flutter.io/)
       package, then use the
       [default Flutter analysis options](https://github.com/flutter/flutter/blob/master/packages/flutter/lib/analysis_options_user.yaml)
       found in `package:flutter`.
-    * If in a Bazel workspace, then use the analysis options in 
+    * If in a Bazel workspace, then use the analysis options in
       `package:dart.analysis_options/default.yaml` if it exists.
     * Use the default analysis options rules.
   * In addition, specific to `dartanalyzer`:
-    * an analysis options file can be specified on the command line via 
+    * an analysis options file can be specified on the command line via
       `--options` and that file will be used instead of searching for an
       analysis options file.
     * any analysis option specified on the command line
       (e.g. `--strong` or `--no-strong`) takes precedence over any corresponding
       value specified in the analysis options file.
 
 * Dartium, dart2js, and DDC
 
   * Imports to `dart:io` are allowed, but the imported library is not supported
     and will likely fail on most APIs at runtime. This change was made as a
@@ skipping 11 matching lines @@
     * No longer produces "UID too large" errors on OS X. All packages are now
       uploaded with the user and group names set to "pub".
     * No longer fails with a stack overflow when uploading a package that uses
       Git submodules.
   * `pub get` and `pub upgrade`
     * Produce more informative error messages if they're run directly in a
       package that uses Flutter.
     * Properly unlock SDK and path dependencies if they have a new version
       that's also valid according to the user's pubspec.
 
+* dartfmt
+  * Make the precedence of cascades more visible.
+  * Fix a couple of places where spurious newlines were inserted.
+  * Correctly report unchanged formatting when reading from stdin.
+  * Other small formatting tweaks.
+
 ## 1.22.0
 
 ### Language
 
-  * Breaking change: 
+  * Breaking change:
     ['Generalized tear-offs'](https://github.com/gbracha/generalizedTearOffs/blob/master/proposal.md)
     are no longer supported, and will cause errors. We updated the language spec
     and added warnings in 1.21, and are now taking the last step to fully
     de-support them. They were previously only supported in the VM, and there
     are almost no known uses of them in the wild.
 
   * The `assert()` statement has been expanded to support an optional second
-    `message` argument 
+    `message` argument
     (SDK issue [27342](https://github.com/dart-lang/sdk/issues/27342)).
 
     The message is displayed if the assert fails. It can be any object, and it
     is accessible as `AssertionError.message`. It can be used to provide more
     user friendly exception outputs. As an example, the following assert:
 
     ```dart
     assert(configFile != null, "Tool config missing. Please see https://goo.gl/k8iAi for details.");
     ```
 
@@ skipping 1641 matching lines @@
     they will keep the Dart process alive until they time out. This fixes the
     handling of persistent connections. Previously, the client would shut down
     immediately after a request.
 
   * **Breaking change:** `HttpServer` no longer compresses all traffic by
     default. The new `autoCompress` property can be set to `true` to re-enable
     compression.
 
 * `dart:isolate`: `Isolate.spawnUri` added the optional `packageRoot` argument,
   which controls how it resolves `package:` URIs.