arrow functions without { } about njstrace

[retorquere]

This can be solved easily with help of putout code transformer, here is how it can look like:

Isn't there a return a missing in that codemod result? (a) => a means "return the input"

[retorquere]

No, I mean, was it published in such a way that I can npm install it as-is as a putout plugin?

[ValYouW]

Yeah, that's tricky as there is no body function where I can inject the tracing code in...

[coderaiser]

This can be solved easily with help of putout code transformer, here is how it can look like:

Also as I understand ESM not supported because it requires using loaders, right?

[ValYouW]

Hi,
Thx.
Never looked on ESM to be honest...

[coderaiser]

Hi,
Thx.
Never looked on ESM to be honest...

Just landed putout-based function tracer ESTrace for ESM.

[coderaiser]

Isn't there a return a missing in that codemod result? (a) => a means "return the input"

Yes, you right, thank you! Fixed with coderaiser/estrace@386c44c, landed in v1.1.0 🎉 .

@ValYouW you are done a really great job with njsTrace!

Instrumentation just adds calls to njstrace tracing methods at the beginning of each function, at the end of each function, and before any return statement.

I just tried a couple different ways:

• Wrap all functions with a __estrace call:

hello(__esTrace('name', 'url', function(word) {
    return `hello ${word}`;
}));

But it has problems when we have function with ExportNamedDeclaration with FunctionDeclaration:

export function hello() {
}

will be converted to:

// invalid
export __esTrace('name', 'url', function() {
});

Which has invalid syntax.

• bind __estrace with context and args:

function hello() {
    return esTrace.bind(this, 'hello', 'file://1.js', function hello() {
    });
};

Has problems with:

const a = (b) => (c) => d;

Because of recursion while building (and possible executing) instrumented code.

So your way is the best, thank you!

[retorquere]

Can I reuse this plugin in my own build (esbuild.js)? I have a private copy currently and that will grow stale.

[coderaiser]

Can I reuse this plugin in my own build (esbuild.js)? I have a private copy currently and that will grow stale.

Of course, why not :)

[coderaiser]

No, I mean, was it published in such a way that I can npm install it as-is as a putout plugin?

Yes you can, it will look like:

import putout from 'putout';
import estracePlugin from 'estrace/plugin';

const source = `
    const fn = (a) => a;
`;

const {code} = putout(source, {
    plugins: [
        ['estrace', estracePlugin],
    ],
});

console.log(code);