traceResolution "according to earlier cached lookups" is noisy

[IanVS]

Suggestion

🔍 Search Terms

according to earlier cached lookups
traceResolution

✅ Viability Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

I've been experimenting with different forms of module resolution in preparation for an upcoming talk, and the --traceResolution flag has been amazingly helpful. However, there are some cases, particularly when using "moduleResolution": "NodeNext" when, at the end of the trace, I get a ton of duplicate cache lookup logs.

For example:

======== Module name 'exports' was successfully resolved to '/Users/ianvs/code/experiments/ts-module-resolution-examples/src/NodeNext/node_modules/exports/index.d.ts'. ========
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist.
Found 'package.json' at '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json'.
'package.json' does not have a 'typesVersions' field.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/Users/ianvs/code/experiments/ts-module-resolution-examples/node_modules/typescript/package.json' exists according to earlier cached lookups.

...except I get about 5 times as many lines as shown here.

I don't know if this indicates a problem, or it's just a normal part of the resolution process, but maybe those logs could at least be cleaned up and they could be combined with a (x24) at the end, or something?

📃 Motivating Example

I plan to use --traceResoltuion in a meetup talk, and the extra output is a bit distracting.

I've pushed up a reproduction at https://github.com/IanVS/ts-module-resolution-examples/tree/d857f0e2fa44f3b5c14d30049fe95ee47074a75f

Run npm install then npm run repro to see the behavior I'm discussing here.

💻 Use Cases

Improving the output of --traceResolution will make it more friendly for developers to use.

On the other hand, if this does indicate a possible problem, then adding visibility by having this huge block of repeating text might be a good thing, so I could see wanting to keep it if that's the case.

[sheetalkamat]

This is currently by design as package.json for each source file is looked up. But 9b4191f kind of helps with this.

[IanVS]

I see, thanks. Feel free to close the issue, I just wanted to bring it up.