npmpackage.info

hermes-profile-transformer

TypeScript tool for converting Hermes Sampling Profiler output to Chrome Dev Tools format

0.0.9

MIT

TypeScript

10.44 kB

190,488,066 2.9

Installations

npm install hermes-profile-transformer

Pull Requests

Open

16

Total

33

Closed

4

Merged

13

Issues

Open

7

Total

23

Closed

16

Releases

Unable to fetch releases

Developer

react-native-community

Developer Guide

BETA

Module System

CommonJS

Min. Node Version

>=8

Typescript Support

No

Node Version

NPM Version

Statistics

86 Stars

96 Commits

9 Forks

8 Watching

15 Branches

69 Contributors

Updated on 15 Aug 2024

Bundle Size

34.96 kB

Minified

10.44 kB

Minified + Gzipped

Bundlephobia

Languages

TypeScript (100%)

Total Downloads

Cumulative downloads

Total Downloads

190,488,066

Last day

-6.1%

269,660

Compared to previous day

Last week

-0.2%

1,415,947

Compared to previous week

Last month

2.5%

6,201,687

Compared to previous month

Last year

34.1%

75,934,484

Compared to previous year

Daily Downloads

Weekly Downloads

Monthly Downloads

Yearly Downloads

Dependencies

source-map

Dev Dependencies

husky tsdx tslib typescript

Versions

Hermes Profile Transformer

Visualize Facebook's Hermes JavaScript runtime profile traces in Chrome Developer Tools.

Overview

The Hermes runtime, used by React Native for Android, is able to output Chrome Trace Events in JSON Object Format.

This TypeScript package converts Hermes CPU profiles to Chrome Developer Tools compatible JSON Array Format, and enriches it with line and column numbers and event categories from JavaScript source maps.

Usage

If you're using hermes-profile-transformer to debug React Native Android applications, you can use the React Native CLI react-native profile-hermes command, which uses this package to convert the downloaded Hermes profiles automatically.

As a standalone package

1const transformer = require('hermes-profile-transformer').default;
2const { writeFileSync } = require('fs');
3
4const hermesCpuProfilePath = './testprofile.cpuprofile';
5const sourceMapPath = './index.map';
6const sourceMapBundleFileName = 'index.bundle.js';
7
8transformer(
9  // profile path is required
10  hermesCpuProfilePath,
11  // source maps are optional
12  sourceMap,
13  sourceMapBundleFileName
14)
15  .then(events => {
16    // write converted trace to a file
17    return writeFileSync(
18      './chrome-supported.json',
19      JSON.stringify(events, null, 2),
20      'utf-8'
21    );
22  })
23  .catch(err => {
24    console.log(err);
25  });

Creating Hermes CPU Profiles

Opening converted profiles in Chrome Developer Tools

Open Developer Tools in Chrome, navigate to the Performance tab, and use the Load profile... feature.

API

transformer(profilePath: string, sourceMapPath?: string, bundleFileName?: string)

Parameters

Parameter	Type	Required	Description
profilePath	string	Yes	Path to a JSON-formatted `.cpuprofile` file created by the Hermes runtime
sourceMapPath	string	No	Path to a source-map compatible Source Map file
bundleFileName	string	No	If `sourceMapPath` is provided, you need to also provide the name of the JavaScript bundle file that the source map applies to. This file does not need to exist on disk.

Returns

Promise<DurationEvent[]>, where DurationEvent is as defined in EventInterfaces.ts.

Resources

Using Hermes with React Native.
Chrome Trace Event Format. Hermes uses the JSON Object format.
Measuring JavaScript performance in Chrome

LICENSE

MIT

No vulnerabilities found.

10

Dangerous-Workflow

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10

Binary-Artifacts

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10

License

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1

Code-Review

Determines if the project requires human code review before pull requests (aka merge requests) are merged.

0

Maintained

Determines if the project is "actively maintained".

0

Pinned-Dependencies

Determines if the project has declared and pinned the dependencies of its build process.

0

Token-Permissions

Determines if the project's workflows follow the principle of least privilege.

0

CII-Best-Practices

Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.

0

Fuzzing

Determines if the project uses fuzzing.

0

Security-Policy

Determines if the project has published a security policy.

0

SAST

Determines if the project uses static code analysis.

0

Vulnerabilities

Determines if the project has open, known unfixed vulnerabilities.

Score

2.9

/10

Last Scanned on 2024-11-18

The Open Source Security Foundation is a cross-industry collaboration to improve the security of open source software (OSS). The Scorecard provides security health metrics for open source projects.

Learn More

Other packages similar to hermes-profile-transformer

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Flow types for the Flow-ESTree spec produced by the hermes parser

babel-plugin-syntax-hermes-parser

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Babel plugin which switches Babel to use the Hermes parser.

hermes-parser

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A JavaScript parser built from the Hermes engine