Disable MSBuild TypeScript Compile
Add the property <TypeScriptCompileBlocked>true</TypeScriptCompileBlocked> to a PropertyGroup in your csproj file (I added it under the Configuration label). This should disable all msbuild based TS compilation.
With this setting enabled you shouldn't need the tsconfig.json settings compileOnSave/buildOnSave.
If you are on an older version of Visual Studio (I had implicitly thought about VS 2017 or xproj with 2015), the property may be <TypeScriptEnabled>false</TypeScriptEnabled>.
I had this issue, tested all the things that was posted here without success,
But after adding this, things worked:
<TypeScriptToolsVersion>3.9</TypeScriptToolsVersion>Seems like the version that I was using did compile no matter the settings.
For Visual Studio 2015, adding below line under PropertyGroup helped me.
<TypeScriptCompileBlocked>true</TypeScriptCompileBlocked>