Missing Interfaces and other elements in the Graph

[JohT]

Hi 👋,

i'm getting a lot of error messages when trying to scan react-router (as an example).
Most of them are

• Error: external module ... for re-export could not be found: Ignoring export... and
• Error: Could not resolve module:....

Details see attached log below. I'm not sure if these messages are ok or not.

Anyway, I suspect missing data in the Graph. For example, I can't find an Interface node for Location or the (re)exported type of it in the type of it in the index.ts. There is only a ExternalDeclaration where I couldn't find a way to find out if this is a type, interface or class. Overall, I only get 16 Interfaces. There should be more than 50 if I counted them right in my IDE.

Are there any additional steps I need to take care of before I start the scan? Are only specific project structures supported? Or might this be a bug?

Use case

As a software engineer that keep an eye on micro architecture I'm not only interested in dependencies between modules but also on how strong the resulting coupling might be. Calling a function or extending a class from another module leads to more coupling than for example referencing a type alias or an interface.

I want to query the number of interfaces a module uses from another one, the number of types (type aliases), the number of function calls, etc. .This will then also help to calculate a kind of "Abstractness" similar to Object Oriented Design Metrics ( Archived Example ).

Steps to reproduce

• Clone https://github.com/remix-run/react-router.git
• Run yarn install || yarn
• Run npx --yes @jqassistant/ts-lce >jqassostant-typescript-scan.log
• Result that I got: jqassostant-typescript-scan.log, ts-output.json

If I can provide any additional information or help let me know.

Thanks 🙏 very much.
Johannes

[SebastianWendorf]

I looked into this problem: It has to do with how the project is set up.
At the moment this plugin mainly focuses on mechanisms directly provided by TypeScript, largely ignoring surrounding technologies like Node.js. React-Router has a project setup that would require parsing the different package.json files and connect their information to the individual TypeScript projects to correctly resolve the package names in the imports/re-exports.
In its current state the plugin doesn't support this, as only tsconfig.json files are considered for resolving declarations.

Nevertheless I think this would represent a sensible addition to the plugin.

[SebastianWendorf]

Another part of error messages is caused by the fact that there are exports of declarations that are located in local modules that are not included in the TypeScript program via the tsconfig.json. As such they are treated as external declarations, which leads to the error messages.
An example of this can be seen in packages/router/index.ts where there are re-exports of declarations from the history.ts module. In the tsconfig.json, however, only the index.ts file is directly included in the program.

EDIT: I think the problem is, that currently indirect inclusions that are added to the program automatically are not considered as internal sources by the plugin. I'm looking into this.