Repository: TypeScript
Issue: [Feature Request] Print project directory when diagnostics enabled
Labels: Suggestion,Awaiting More Feedback

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## Search Terms

<!-- List of keywords you searched for before creating this issue. Write them down here so that others can find this suggestion more easily -->

diagnostics, project directory

## Suggestion

<!-- A summary of what you'd like to see added or changed -->

I have about 40+ sub-projects in a `composite` project right now and when building, it takes about 10 minutes.

It's hard to troubleshoot which projects are the bottleneck when I don't even know which projects are being built.

Enabling diagnostics only tells me how long a project took but doesn't tell me what that project is.

So, my feature request is to print the project directory when `diagnostics` is enabled.

-----

At the moment, I've modified my own `tsc.js`,

```ts
//Find this line
reportTimeStatistic("Total time", programTime + bindTime + checkTime + emitTime);
```

```ts
//Replace with this snippet
reportTimeStatistic("Total time", programTime + bindTime + checkTime + emitTime);
if (program.getRootFileNames().length > 0) {
    const path = program.getRootFileNames()[0].replace(/\/[^/]+?\.[^.]+?$/, "");
    reportStatisticalValue("Project", (
        path.indexOf(program.getCurrentDirectory()) == 0 ?
            path.substr(program.getCurrentDirectory().length) :
            path
    ));
}
```

It works enough for me,
```
Files:                                      2944
Lines:                                    279749
Nodes:                                   1473021
Identifiers:                              417022
Symbols:                                  295304
Types:                                        73
Memory used:                             748010K
Assignability cache size:                      0
Identity cache size:                           0
Subtype cache size:                            0
I/O Read time:                             0.02s
Parse time:                                0.21s
Program time:                              0.84s
Bind time:                                 0.18s
printTime time:                            0.01s
Emit time:                                 0.01s
I/O Write time:                            0.01s
Total time:                                1.03s
Project:                  /src/app-route-handler
```

-----

I don't really know much about the TypeScript API. There's probably a proper way to get this information but with my limited knowledge, I managed to hack that together.

## Checklist

My suggestion meets these guidelines:

* [X] This wouldn't be a breaking change in existing TypeScript/JavaScript code
* [X] This wouldn't change the runtime behavior of existing JavaScript code
* [X] This could be implemented without emitting different JS based on the types of the expressions
* [X] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
* [X] This feature would agree with the rest of [TypeScript's Design Goals](https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals).