Remove the File not found or not accessible tracing warning and declare runtime only modules

[DarkHarlock]

I'm submitting a feature request

• Library Version:
  0.32.0

Please tell us about your environment:

• Operating System:
  All

• Node Version:
  7.10.0

• NPM Version:
  4.2.0

• Browser:
  all

• Language:
  all

• Loader/bundler:
  all

Current behavior:

When a module is only available at deploy/run time the builder reports something like:

Tracing app...
 ------- File not found or not accessible ------
| Location: D:/vscode/cli-test/src/my-awesome-module.js
| Requested by: D:/vscode/cli-test/src/app.js
| Is this a package? Make sure that it is configured in aurelia.json and that it is not a Node.js package
 -----------------------------------------------

• What is the expected behavior?

This report is very useful to detect missing files or dependencies, but in some cases, for known dependencies, this behavior requires a way to be overridden.

On my side what I need is an entrypoint inside the aurelia.json where I can specify a list of modules to stub with some related dependencies.

It could be something like:

{
  "name": "cli-test",
  "build": {
    "loader": {
      "externalModules": {
        "my-awesome-module": ["infrastructure/service1", "other"]
      }

where my-awesome-module is the missing file reported by the build and infrastructure/service1 and other are some dependencies of the declared module that must exists inside this build.
So, if the previous configuration is applied and the following report is displayed, I can regard it as a build issue.

Tracing app...
 ------- File not found or not accessible ------
| Location: D:/vscode/cli-test/src/other.js
| Requested by: D:/vscode/cli-test/src/app.js
| Is this a package? Make sure that it is configured in aurelia.json and that it is not a Node.js package
 -----------------------------------------------

After some investigation on your code I found that this can be solved intercepting the amodro-trace dependency tracking using the readFile function parameter passed to the trace call. Here you can inject some custom content for my-awesome-module like define(['infrastructure/service1', 'other'], function() {}).

The hook, adapted from the Non-file inputs section of the amodro-trace documentation example, can be something like:

fileRead: function(defaultRead, id, filePath) {
  if (id in loaderOptions.externalModules) {
    let externalContent = makeModuleContent(loaderOptions.externalModules[id]); // return "define(['infrastructure/service1', 'other'], function() {})"
    return externalContent;
  }
  //...

If you are interested on this and the possible solution listed above is acceptable I can provide a PR in the next days.

• What is the motivation / use case for changing the behavior?

There are mostly 2 use cases that needs this, and are:

• modules defined at runtime using a call to the define method
• modules available only at deploy time eg. plugins, for customer customization, bundles from other projects, etc ...

[JeroenVinke]

Yes!! I am definitely interested, as this could also play a role in adding electron support. Thank you for looking into it