Updating rntuple test.js with new Unit tests Checking first and last entries

[Krmjn09]

Created 4 fields with these entry values

for (int i = 0; i < 10; ++i) {
*intField = i;
*floatField = static_cast(i * i);
*doubleField = i * 0.5;
*stringField = "entry_" + std::to_string(i);
writer->Fill();
}

and then checked the rntuple_test.root file in rntuple_test.js
Its working successfully fine as you can see in the below result

[silverweed]

Pay attention when comparing floating point numbers with ===: due to floating point errors you might get some false negatives where two numbers that should be the same are not identical. So usually instead of x === y you want to use Math.abs(x - y) < EPSILON, where EPSILON is a small number (like 1e-10).
And I believe this is also true for "integers" in javascript, as all numbers are floating points unless you specifically use special types.

[silverweed]

Since you have few entries and you constructed them in a way that's easy to programmatically reproduce, you can also loop over all the entries and calculate the expected values in the loop, rather than hardcoding it in expected

[silverweed]

lgtm, thanks.
Please fix the eslint warning before we merge