Visual Studio 2017 Compile on Save only compiles the current file

Windows 10 Version 1607

Microsoft Visual Studio Enterprise 2017
Version 15.3.3

TypeScript Version: 2.4.1 Release

Using the exact same solution (see example below) under VS2015 and VS2017, which uses "compileOnSave", VS2017 is not building any of the files listed under the "include" folders, when saving the single file listed in the "files" section. The only output is for that one file, when the file is saved. It is now also only outputting the single file being saved that is a part of the "include" section, Previously, it was building all of the files in that folder.

Can we get back the normal functionality of TSC.exe (watch), which was available in VS2015? This currently functionality is basically useless. Also, if the output files are checked-in to source control, VS2017 is not automatically checking them out like VS2015 does, which is another piece that has been broken.

Sample Project: https://developercommunity.visualstudio.com/storage/attachments/10591-typescriptbug.zip

Steps to reproduce the issue:

1. Open the solution in VS2015.
2. Open ~/Scripts/_apps/tsTest/tsTest.ts for edit.
3. Save the file (CTRL-S).
4. Look on your file system for the ~/Scripts/.tsbuild folder.
5. You will see that all files were built.
6. Close VS2015.
7. Delete the ~/Scripts/.tsbuild folder.
8. Open the solution in VS2017.
9. Open ~/Scripts/_apps/tsTest/tsTest.ts for edit.
10. Save the file (CTRL-S)
11. Look on your file system for the ~/Scripts/.tsbuild folder.
12. You will immediately see that there is no _modules folder.

VS2017 is not using TypeScript correctly.

[mhegazy]

looks like another report of #18130

I created #17355, but it was marked closed as fixed, even though the problem still exists. This is not a duplicate of #18130, and covers source control issues as well.

[minestarks]

There's currently a more detailed discussion about this issue here: https://developercommunity.visualstudio.com/content/problem/97205/broken-typescript-compileonsave-build-tooling-for.html

Essentially, VS 2017 should probably do a full build of the project when save is invoked for the first time, and incremental builds on saves thereafter. I'm not 100% sure of the ramifications of doing so, we might have rejected it for perf reasons in the past.

The fix could be in tsserver or VS depending on how you look at it.

Here is a summary of the answers to questions that @minestarks asked:

Our solution has several individual applications that transpile many TypeScript files into single JavaScript files, and the ES5 JavaScript output files are stored in TFS (multiple tsconfig.json files). However, we also have 2 large applications (with their own tsconfig.json files) that consist of over 30 TypeScript files each. They need to be transpiled into transient output files, fed into WebPack, and the ES5 JavaScript output from WebPack is stored in TFS. The transient output files are not stored in TFS. Also, unlike VS2015, VS2017 is failing to check-out the output file prior to attempting to write to it, causing the output to silently fail.

We have disabled the TypeScript compile-on-build ability via .csproj entries, as we never want any TypeScript code to build during a solution/project build. Only developers who are actually making changes to the TypeScript code will update the JavaScript output files. The developers that don't change the TypeScript files, use the previously transpiled JavaScript files that are in TFS, which later get deployed and published to production.

I'm not sure if this is related to my problem or not. If not, I will raise a separate issue.

We have a number of TypeScript files inside C# projects, and use the "Compile Files Not Part of a Project" setting to compile them into AMD modules (ECMAScript 5 level). In the latest Visual Studio 2017 some files are not being compiled on save (can't see any pattern in this).

The files that are being compiled are generating wildly different code from VS2015 which is not valid JavaScript (or at least, cannot be loaded by require.js).

import ko = require('knockout');
import log = require('loglevel');
import options = require('options');

var titleSource: KnockoutObservable<KnockoutObservable<string>> = ko.observable(null);

var title = ko.pureComputed(() => {
    var source = titleSource();

    if (ko.isObservable(source))
        return source();

    return options.resources['bwf_explorer'];
})

var titleViewModel = {
    pageTitle: title
};

ko.applyBindings(titleViewModel, document.getElementsByTagName("head")[0])

class Title {
    setTitle(title: KnockoutObservable<string> | string) {
        if (ko.isObservable(title))
            titleSource(title);
        else if (title != null)
            titleSource(ko.observable(title));
        else
            titleSource(null);
    }

    clearTitle() {
        titleSource(null);
    }
}

var titleFacade = new Title();
export = titleFacade;

becomes

"use strict";
var ko = require("knockout");
var options = require("options");
var titleSource = ko.observable(null);
var title = ko.pureComputed(function () {
    var source = titleSource();
    if (ko.isObservable(source))
        return source();
    return options.resources['bwf_explorer'];
});
var titleViewModel = {
    pageTitle: title
};
ko.applyBindings(titleViewModel, document.getElementsByTagName("head")[0]);
var Title = (function () {
    function Title() {
    }
    Title.prototype.setTitle = function (title) {
        if (ko.isObservable(title))
            titleSource(title);
        else if (title != null)
            titleSource(ko.observable(title));
        else
            titleSource(null);
    };
    Title.prototype.clearTitle = function () {
        titleSource(null);
    };
    return Title;
}());
var titleFacade = new Title();
module.exports = titleFacade;
//# sourceMappingURL=bwf-title.js.map

which fails to load at runtime (via requirejs 2.1.8) since module is undefined.

[minestarks]

@john-cullen this sounds like an unrelated issue.

We have a number of TypeScript files inside C# projects, and use the "Compile Files Not Part of a Project" setting to compile them into AMD modules (ECMAScript 5 level).

So if I understand you correctly, the TypeScript files are part of the project? In that case, the "compile files not part of a project" setting may not apply. You may want to go into project properties -> TypeScript Build and select AMD as the module kind. Alternatively, if you're using a tsconfig.json, make sure the module kind is specified there, or if you're using MSBuild, you can use the TypeScriptModuleKind property.

The generated code in your example is valid JavaScript, it's just generating CommonJS modules, not AMD.

In the latest Visual Studio 2017 some files are not being compiled on save (can't see any pattern in this).

If this persists, please file a feedback item through Visual Studio -> Help -> Report a Problem.

Thanks for reporting!

@minestarks hi, sorry I was unclear.

The typescript files we have are not part of a typescript project, they are in class library projects so there is no TypeScript Build settings in the Project itself. We aren't using a tsconfig either.

The project works as expected without modification in VS 2015.

@minestarks Is there any update on the status of this? I see that 15.4 was released today, and that it is not in the release. Thanks