test: migrate stats/base/dists/exponential/mgf to ULP-based testing

[yb175]

Resolves a part of #11352.

Description

This PR migrates the numerical fixture checks for stats/base/dists/exponential/mgf from relative-tolerance comparisons to ULP assertions in test.factory.js, test.mgf.js, and test.native.js.

The ULP thresholds were determined by sweeping the small, medium, and large fixture sets and selecting the minimum passing bounds. The native addon was built locally, and the JavaScript main export, factory, and native implementation were checked. Their maximum ULP differences matched:

• Small: 49 ULP
• Medium: 362 ULP
• Large: 212 ULP

The package tests passed twice with these bounds.

Related Issues

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

Questions

No.

Other

Only the three test files are changed.

Verification:

• make test TESTS_FILTER=".*/stats/base/dists/exponential/mgf/.*" passed twice (3015 assertions each run).

Checklist

• Read, understood, and followed the contributing guidelines

AI Assistance

• Yes
• No

[stdlib-bot]

Hello! Thank you for your contribution to stdlib.

We noticed that the contributing guidelines acknowledgment is missing from your pull request. Here's what you need to do:

1. Please read our contributing guidelines.

2. Update your pull request description to include this checked box:

   - [x] Read, understood, and followed the [contributing guidelines](https://github.com/stdlib-js/stdlib/blob/develop/CONTRIBUTING.md)

This acknowledgment confirms that you've read the guidelines, which include:

• The developer's certificate of origin
• Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!

[stdlib-bot]

👋 Hi there! 👋

And thank you for opening your first pull request! We will review it shortly. 🏃 💨

Getting Started

• Please read our contributing guidelines if you haven't already.
• For development guidance, refer to the development guide.

Next Steps

1. A project maintainer will approve GitHub Actions workflows for your PR.
2. All CI checks must pass before your submission can be fully reviewed.
3. You'll need to address any failures in linting or unit tests.

Running Tests Locally

You can use make to run any of the CI commands locally from the root directory of the stdlib repository:

# Run tests for all packages in the math namespace:
make test TESTS_FILTER=".*/@stdlib/math/.*"

# Run benchmarks for a specific package:
make benchmark BENCHMARKS_FILTER=".*/@stdlib/math/base/special/sin/.*"

If you haven't heard back from us within two weeks, please ping us by tagging the "reviewers" team in a comment on this PR.

If you have any further questions while waiting for a response, please join our Zulip community to chat with project maintainers and other community members.

We appreciate your contribution!

Documentation Links

• Contributing Guidelines
• Development Guide
• Zulip Chat
• make rules for running examples
• make rules for running unit tests
• make rules for running benchmarks

[stdlib-bot]

Hello! Thank you for your contribution to stdlib.

We noticed that the contributing guidelines acknowledgment is missing from your pull request. Here's what you need to do:

1. Please read our contributing guidelines.

2. Update your pull request description to include this checked box:

   - [x] Read, understood, and followed the [contributing guidelines](https://github.com/stdlib-js/stdlib/blob/develop/CONTRIBUTING.md)

This acknowledgment confirms that you've read the guidelines, which include:

• The developer's certificate of origin
• Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!

[stdlib-bot]

Hello! Thank you for your contribution to stdlib.

We noticed that the contributing guidelines acknowledgment is missing from your pull request. Here's what you need to do:

1. Please read our contributing guidelines.

2. Update your pull request description to include this checked box:

   - [x] Read, understood, and followed the [contributing guidelines](https://github.com/stdlib-js/stdlib/blob/develop/CONTRIBUTING.md)

This acknowledgment confirms that you've read the guidelines, which include:

• The developer's certificate of origin
• Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!

[kgryte]

LGTM

[stdlib-bot]

Coverage Report

No coverage information available.

[kgryte]

Thank you for your contribution and congratulations on your first PR!

[yb175]

thanks !
looking forward to contribute more