dotnet/roslyn

FormatAsync removes whitespace outside the requested bounds

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#50,129 opened on Dec 24, 2020

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 (13 comments) (0 reactions) (0 assignees)C# (4,257 forks)batch import
Area-IDEConcept-Continuous ImprovementIDE-Formatterhelp wanted

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Description

Version Used: 3.8.0

Steps to Reproduce:

Consider the following code:

class C
{
    public void M()
    {
        // There is a space after the ; here, and 8 spaces on the next line.
        var i = 1; 
        
    }
}

If I make a FormatAsync call, with the bounds [109..130), I get back a text change removing both the space on the end of the var line and the spaces on the line after, with a changed span of [127..138). This span is outside the bounds of what I asked for. In practice, what this means that if I have on-type formatting turned on in vscode and I have a trailing space, FormatAsync will remove the auto-indentation added in to put my cursor, when all that was asked to be formatted was the previous line.

Contributor guide

Research direction
Examine the FormatAsync implementation in Roslyn's formatter, specifically how it handles text bounds and whitespace removal. Trace the logic that causes it to modify text outside the requested range.
Tech stack
csharp
Domain
backenddeveloper experience
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C#Roslyn API basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40