"Only format modified text" does not format the first line of modified text

[dcharkes]

@DanTup would it be possible to get support for VSCode feature to only format changed chunks?

https://code.visualstudio.com/updates/v1_49#_only-format-modified-text

settings.json:

    "dart.enableSdkFormatter": true,
    "editor.formatOnSave": true,
    "editor.formatOnSaveMode": "modificationsIfAvailable",

This causes nothing to be formatted for me.

[DanTup]

Do you have an example of changes not being formatted? It seems to work for me, although the first line doesn't seem to be formatted (this feels like a bug - if it's not the same thing you're seeing I'll open a new issue and fix, though if it's the same we can reuse this one).

I presume you have Git (or other scm) enabled in VS Code? It only works if they're enabled in VS Code since that's how it gets the modified ranges (they show with a green bar in the gutter).

[dcharkes]

Sorry for the slow response.

I ran into this when opening a workspace with two folders

	"folders": [
		{
			"path": "flutter/dev/bots"
		},
		{
			"path": "flutter/dev/docs"
		}
	],

https://github.com/flutter/flutter/tree/master/dev/bots
https://github.com/flutter/flutter/tree/master/dev/docs

Editing flutter/dev/bots/analyze_sample_code.dart

After hitting save nothing happens:

[dcharkes]

dacoharkes@dacoharkes-linux:~/flt/flutter/dev/bots$ flutter --version
Flutter 2.6.0-12.0.pre.173 • channel pub-global-run-workaround • git@github.com:flutter/flutter.git
Framework • revision 4b96c18650 (2 weeks ago) • 2021-10-01 13:55:50 +0000
Engine • revision 2db4319447
Tools • Dart 2.15.0 (build 2.15.0-168.0.dev)
dacoharkes@dacoharkes-linux:~/flt/flutter/dev/bots$ dart --version
Dart SDK version: 2.15.0-168.0.dev (dev) (Thu Sep 30 12:23:13 2021 -0700) on "linux_x64"

Version: 1.61.0
Commit: ee8c7def80afc00dd6e593ef12f37756d8f504ea
Date: 2021-10-07T18:11:58.853Z
Electron: 13.5.1
Chrome: 91.0.4472.164
Node.js: 14.16.0
V8: 9.1.269.39-electron.0
OS: Darwin x64 20.6.0

Using VSCode remote from MacBook to a Linux cloudtop.

Extensions, disabled all local/remote extensions except for the Dart/Flutter and VSCode Remote extensions.

[DanTup]

@dcharkes is it only the first line of the modified range that's not formatted? If you modify multiple consecutive lines and save, do the others format?

To support format range, we're diffing the formatted code from dart_style to generate smaller edits, then keeping only those within the range. This means the whitespace change that spans where the line starts is being dropped. I'll see if I can coe up with a way to handle this (though I want to be sure it's the only issue you're seeing, in case there's more).

[dcharkes]

[DanTup]

@dcharkes it's not obvious from the screenshot, but is it still doing nothing at all, or just producing incorrect formatting? Do you have Git enabled in VS Code (so the modified lines have a green mark in the gutter - perhaps that's what your green bg is)?

If you can share an exact sample file and log file, that might help me reproduce. You can capture a log with the Dart: Capture Analysis Server Logs command (best done on a small sample project - you can email logs to me at logs@dartcode.org if you don't want to attach here). Thanks!

[dcharkes]

Sorry for not being clear, it's doing nothing at all.

Yes, the green background was from a diff-view.

Repro logs:
https://gist.github.com/dcharkes/d3d7c3af5f5b8a65652931d0a7275802

I do not see any "format" in the log at all.

[DanTup]

Oh, it looks like you're not using LSP:

Analyzer type: DAS

Do you have dart.previewLsp: false in your setting? The original protocol doesn't support range-formatting, so it's only available over LSP. LSP should be enabled by default now, although I didn't remove previewLsp so those that disabled it to work around issues in the past may still have it disabled. I'll file an issue to rename that flag to something clearer, which will re-enable it for everyone unless the disable it with the new (non-preview) setting (although note that in the future, LSP will be the only option - the non-LSP code is not being maintained in the VS Code extension).

[dcharkes]

That's it! Now it's only the first line that's not being formatted.

Thanks again for your help @DanTup !

[DanTup]

Great! Let's keep this issue open to cover the first line issue then. Thanks!