Duplicate identifier error for d.ts files in Visual Studio 2017

[odrozd]

TypeScript Language Version: 2.2
Visual Studio Typescript tooling Version 2.1.5

I am having trouble with typescript errors like TS2300: duplicate identifier 'export=' and TS2374: Duplicate string index signature. This errors appear in error window, but projects builds successful. This errors appear only with VS2017.

Env Details:

1. Type definitions are installed via nuget to default folder: project root/scripts/typings/

2. For build I use nuget package Microsoft.TypeScript.MSBuild" version="2.2.1

3. tsconfig is NOT used**, instead here are setting from csproj:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <TypeScriptTarget>ES5</TypeScriptTarget>
    <TypeScriptJSXEmit>None</TypeScriptJSXEmit>
    <TypeScriptCompileOnSaveEnabled>True</TypeScriptCompileOnSaveEnabled>
    <TypeScriptNoImplicitAny>False</TypeScriptNoImplicitAny>
    <TypeScriptModuleKind>AMD</TypeScriptModuleKind>
    <TypeScriptRemoveComments>False</TypeScriptRemoveComments>
    <TypeScriptOutFile>
    </TypeScriptOutFile>
    <TypeScriptOutDir />
    <TypeScriptGeneratesDeclarations>False</TypeScriptGeneratesDeclarations>
    <TypeScriptNoEmitOnError>True</TypeScriptNoEmitOnError>
    <TypeScriptSourceMap>True</TypeScriptSourceMap>
    <TypeScriptMapRoot />
    <TypeScriptSourceRoot />
    <TypeScriptStrictNullChecks>false</TypeScriptStrictNullChecks>
    <TypeScriptNoFallthroughCasesInSwitch>true</TypeScriptNoFallthroughCasesInSwitch>
    <TypeScriptLib>dom,es5,es2015.promise</TypeScriptLib>
  </PropertyGroup>

I assume I see this errors because VS2017 somehow downloaded @types to this folder: ~\AppData\Local\Microsoft\TypeScript\node_modules@types\ and there is conflict between this types definitions and those types installed via nuget, if this is the cause I am not sure how disable this feature in VS2017 and honor only nuget installed d.ts?

I would appreciate any help to this issue.

Here is screenshot:

[mhegazy]

Can you share your project file? or steps to reproduce this behavior?

[odrozd]

I can share stripped proj file with only typescript related information, not sure if it helps.
IssueVS2017csproj.zip

Regarding steps to reproduce, there isn't I just open VS and in 20-30 seconds I start see this errors in error window, please note project builds successful, VS point to this errors in d.ts files. Also my team-members also have this issue with vs2017.

Another screenshot:

Also I will try to create project from scratch with similar settings and check if this issue exist.

[Serivy]

I was just about to add a new issue but I believe this is the same issue I am having. I have managed to replicate it in a simple project (our production project is much more complicated and uses nuget but still suffers from the issue).

To reproduce:

1. git clone https://github.com/Serivy/TS5055.git
2. Open TS5055.sln with visual studio 2017.
3. Compile the project (so that the artefact file1.d.ts is created)
4. Close visual studio 2017
5. Open TS5055.sln with visual studio 2017 and open the Error List.
6. Wait 40 seconds.
7. The errors should pop up.
   

I have used each RC build of VS2017 and i can say it was fine until the very last RC (which i think was using the TS2.2 plugin) which i was hoping would be fixed in the release but can confirm i get it in the release as well. This is only for design time as compile time is always correct.

My speculation is that visual studio plugin is sourcing it's own list of files to run through the language service which includes definition files it generates. I have also had it pull .d.ts files from the gulp-typescript package inside a node_modules folder which was listed as exclude in the tsconfig.json.

Any more information required let me know as I have a few cases where this is an issue.

[stewart-r]

Affected by this too - Agree with @Serivy that it seems to be VS sourcing definition files that conflict with ones already in the solution.

Searching for (find in files) one the duplicate identifiers in my solution throws up the same identifier in the typings inside the solution AND one from ...appdata/Local/Microsoft/Typescript/node_modules/@types/...

[odrozd]

I am also can replicate this issue from scratch:

1. Add new MVC5 project,
2. Add any ts file
3. Install jQuery typing via nuget
4. open тгпуе installed jquery.d.ts file in VS editor or wait 20-30 second

Also if I am manually delete typings from folder: "~\AppData\Local\Microsoft\TypeScript\node_modules@types" errors disappear after several seconds, but when reopen VS this folder populated again causing this errors to appear again.

[UsherNet]

Same problem has existed with VS2017 since RC. It would be good to a) understand it, b) make it go away!

[ArtemAvramenko]

Steps to reproduce:

1. Create ASP.NET Web Application (C#)
2. Choose MVC template
3. Install-Package jquery.TypeScript.DefinitelyTyped
4. Open jquery.d.ts

[jurion]

Same problem with WebForms project.

[ArtemAvramenko]

Another error: Duplicate string index signature

"

[LbISS]

The same problem. Just opened solution which worked fine on VS2015 with new VS2017 - can't build, errors:
All declarations of 'iterator' must have identical modifiers.
Duplicate string index signature

[KunleSmart]

I have same problem as indicated by @LbISS. This also include Error TS2300 Duplicate identifier 'ng'.

[intoxopox]

Also triggered by cleaning and rebuilding the solution.