<p dir="auto">If I create a TypeScript project with, say, the following properties directly in the .csproj file</p>
<div class="highlight highlight-text-xml notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&lt;PropertyGroup&gt;
  &lt;TypeScriptOutFile&gt;..\Output\combined.js&lt;/TypeScriptOutFile&gt;
  &lt;TypeScriptOutDir&gt;&lt;/TypeScriptOutDir&gt;
&lt;/PropertyGroup&gt;"><pre class="notranslate">&lt;<span class="pl-ent">PropertyGroup</span>&gt;
  &lt;<span class="pl-ent">TypeScriptOutFile</span>&gt;..\Output\combined.js&lt;/<span class="pl-ent">TypeScriptOutFile</span>&gt;
  &lt;<span class="pl-ent">TypeScriptOutDir</span>&gt;&lt;/<span class="pl-ent">TypeScriptOutDir</span>&gt;
&lt;/<span class="pl-ent">PropertyGroup</span>&gt;</pre></div>
<p dir="auto">Then both msbuild and the compilation triggered by saving a ts file both correctly update the output in the combined.js file in the output folder.</p>
<p dir="auto">However if I extract those properties into an external SharedTypeScript.props file, and instead import the props file in the .csproj file, i.e.</p>
<div class="highlight highlight-text-xml notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&lt;Import Project=&quot;SharedTypeScript.props&quot; /&gt; "><pre class="notranslate">&lt;<span class="pl-ent">Import</span> <span class="pl-e">Project</span>=<span class="pl-s"><span class="pl-pds">"</span>SharedTypeScript.props<span class="pl-pds">"</span></span> /&gt; </pre></div>
<p dir="auto">Then only msbuild will correctly build to the combined.js file in the output folder. Compilation on saving a ts file behaves as if no properties were specified and does not combine the output, instead putting individual js files next to the source ts files.</p>
<p dir="auto">This is using the latest release (<a href="https://github.com/Microsoft/TypeScript/releases/tag/v1.6.2">https://github.com/Microsoft/TypeScript/releases/tag/v1.6.2</a>) and VS2015. This is a regression from VS2013 and typescript 1.4 where this was not a problem.</p>
<p dir="auto">When project does import properties from separate MSBuild file via <code class="notranslate">&lt;Import Project="build.props" /&gt;</code>, The MSBuild is using defined properties, but on file save of TS file it is being ignored.<br>
It worked with with VS13/VS15RC and TS 1.5 beta, but after release it is broken.</p>
<p dir="auto">I can provide ZIP file with example solution, but I cannot add it to github issue.</p>