GraphBasedChecking can break compilation when having unused `open`

[BoundedChenn31]

Not sure if it's a real problem though.

Repro steps
Project file:

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net7.0</TargetFramework>
        <OtherFlags>$(OtherFlags) --test:GraphBasedChecking</OtherFlags>
    </PropertyGroup>

    <ItemGroup>
        <Compile Include="File1.fs" />
        <Compile Include="File2.fs" />
        <Compile Include="Program.fs"/>
    </ItemGroup>

</Project>

File1:

namespace My.Great.Namespace

File2:

namespace My.Great.Namespace

open My.Great.Namespace

type Foo = class end

Program:

printfn "Hello"

Compilation fails with error
1>File2.fs(3,6): Error FS0039 : The namespace or module 'My' is not defined.

But with commented out <OtherFlags> line compilation is successful.
NamespaceIsNotDefRepro.zip

[vzarytovskii]

@nojaf @safesparrow fyi

[vzarytovskii]

@BoundedChenn31 saw your message in the chat, thanks for the minimal repro

[nojaf]

Problematic in what SDK? Reproduceable on main?

[safesparrow]

I reproduced it now on 8.0.100-rc.2. Note that namespace names must match (as showcased in the example code).

[safesparrow]

The problem, as expected, is lack of a dependency from B.fs to A.fs.

This fails:
1.

// A.fs
namespace A

// B.fs
namespace A
open A
type Foo = class end

Graph:

flowchart RL
    0["obj\Debug\net7.0\.NETCoreApp,Version=v7.0.AssemblyAttributes.fs"]
    1["obj\Debug\net7.0\fmodule.AssemblyInfo.fs"]
    2["A.fs"]
    3["B.fs"]

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Trie:

classDiagram

class root

root <|-- ns_Microsoft
class ns_Microsoft {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

ns_Microsoft <|-- ns_BuildSettings
class ns_BuildSettings {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

root <|-- ns_FSharp
class ns_FSharp {

    fmodule.AssemblyInfo.fs(1)
}

root <|-- ns_A
class ns_A {
    B.fs[3]

    A.fs(2)
}

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These succeed:
2.

// A.fs
namespace A

// B.fs
namespace A
open A
module X = ()

Graph:

flowchart RL
    0["obj\Debug\net7.0\.NETCoreApp,Version=v7.0.AssemblyAttributes.fs"]
    1["obj\Debug\net7.0\fmodule.AssemblyInfo.fs"]
    2["A.fs"]
    3["B.fs"]
    3 --> 2

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Trie:

classDiagram

class root

root <|-- ns_Microsoft
class ns_Microsoft {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

ns_Microsoft <|-- ns_BuildSettings
class ns_BuildSettings {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

root <|-- ns_FSharp
class ns_FSharp {

    fmodule.AssemblyInfo.fs(1)
}

root <|-- ns_A
class ns_A {

    A.fs(2)
    B.fs(3)
}

ns_A <|-- mod_X
class mod_X {
    B.fs[3]
}

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// A.fs
namespace A

// B.fs
namespace B
open A
type Foo = class end

Graph:

flowchart RL
    0["obj\Debug\net7.0\.NETCoreApp,Version=v7.0.AssemblyAttributes.fs"]
    1["obj\Debug\net7.0\fmodule.AssemblyInfo.fs"]
    2["A.fs"]
    3["B.fs"]
    3 --> 2

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Trie:

classDiagram

class root

root <|-- ns_Microsoft
class ns_Microsoft {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

ns_Microsoft <|-- ns_BuildSettings
class ns_BuildSettings {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

root <|-- ns_FSharp
class ns_FSharp {

    fmodule.AssemblyInfo.fs(1)
}

root <|-- ns_A
class ns_A {

    A.fs(2)
}

root <|-- ns_B
class ns_B {
    B.fs[3]

}

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[safesparrow]

@nojaf this is reproducible on latest main.

[safesparrow]

Separately, we should consider either escaping the contents of Mermaid graphs, or at least replacing \ with / to avoid \n being presented as a newline:
This mermaid .md file:

flowchart RL
    0["obj\Debug\net7.0\.NETCoreApp,Version=v7.0.AssemblyAttributes.fs"]
    1["obj\Debug\net7.0\fmodule.AssemblyInfo.fs"]
    2["A.fs"]
    3["B.fs"]

yields the below node:

[nojaf]

I can reproduce this with RC2 but not with my local compiler.
@safesparrow could you try:

• git clean -xdf (of fsharp repo)
• dotnet build src/fsc/fscProject/fsc.fsproj /p:BUILDING_USING_DOTNET=true
• <DotnetFscCompilerPath>C:\YourProjectFolder\fsharp\artifacts\bin\fsc\Debug\net8.0\fsc.dll</DotnetFscCompilerPath>

[safesparrow]

@nojaf You're right, my test setup was wrong (I haven't used the compiler from source in a while).

Looks like this is already fixed on main as you said.

Code:

// A.fs
namespace A

// B.fs
namespace A
open A
type Foo = class end

Graph:

flowchart RL
    0["obj\Debug\net7.0\.NETCoreApp,Version=v7.0.AssemblyAttributes.fs"]
    1["obj\Debug\net7.0\fmodule.AssemblyInfo.fs"]
    2["A.fs"]
    3["B.fs"]
    3 --> 2

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Trie:

 classDiagram

class root

root <|-- ns_Microsoft
class ns_Microsoft {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

ns_Microsoft <|-- ns_BuildSettings
class ns_BuildSettings {

    .NETCoreApp,Version=v7.0.AssemblyAttributes.fs(0)
}

root <|-- ns_FSharp
class ns_FSharp {

    fmodule.AssemblyInfo.fs(1)
}

root <|-- ns_A
class ns_A {

    A.fs(2)
}

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