Suggestion: Add a --verbose flag to dart fix --dry-run

[erf]

If you type dart-fix --dry-run now you will get info on which files will be changed, what type of fixes and how many, but not how the actual code will be changed.

I suggest adding a --verbose -v flag to dart fix --dry-run to show the code changes / diffs that will take place with dart fix --apply per fix.

E.g.
dart fix --dry-run -v

Could print:

dart fix --dry-run
Computing fixes in XXX (dry run)... 13.0s

7 proposed fixes in 2 files.

lib/api/somefile.dart
  prefer_const_declarations • 1 fix

Diff:
-            SizedBox(width: 16),
+            const SizedBox(width: 16),

I suggested this in reply to a Tweet from @mit-mit which asked me to file an issue.

• Dart SDK version: 2.17.1
• MacOSX

[mit-mit]

I like this idea; cc @bwilkerson

[bwilkerson]

I like the idea too. @pq and I talked about it when we were first writing dart fix. I believe that the command-line tool has all the information it needs from the server, but we haven't yet investigated to see how hard it would be to produce the diff output. Nor do I know what the priority of this work would be.

[pq]

💯 @Hixie was looking for something similar too (#44728).