dotnet/roslyn

[MSBuildWorkspace] ProjectReferences vs. AllProjectReferences return the same count despite projects not existing in the solution.

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#46,113 opened on Jul 17, 2020

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Area-IDEConcept-Continuous ImprovementIDE-MSBuildWorkspacehelp wanted

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Description

Version Used: master, 16.6.0, etc

Steps to Reproduce:

  1. Create a project A and a project B
  2. Have A reference B
  3. Create a solution X and add only A to it
  4. Use MSBuildWorkspace and OpenSolutionAsync()
  5. Compare A's ProjectReferences to AllProjectReferences

Expected Behavior:

They should be different, because solution X only has A in it.

Actual Behavior:

They are the same because the way a solution is loaded causes project references to be loaded into it even if they're not actually in the solution. See here:

https://github.com/dotnet/roslyn/blob/2a69ac38995a07f4333158b76d2f6e780868401a/src/Workspaces/Core/MSBuild/MSBuild/MSBuildProjectLoader.Worker.cs#L138-L172

Contributor guide

Research direction
Inspect the linked code in MSBuildProjectLoader.Worker.cs around lines 138-172 to understand how project references are loaded. Then compare the ProjectReferences and AllProjectReferences properties to see why they return the same count when a project reference is not in the solution.
Tech stack
csharp
Domain
build system
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
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
GitMSBuild
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70