Viewing github.com/facebook/react/dangerfile.js

```
/**
```

 * Copyright (c) Meta Platforms, Inc. and affiliates.

```
 *
```

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

```
 */
```
```
'use strict';
```

/* eslint-disable no-for-of-loops/no-for-of-loops */

// Hi, if this is your first time editing/reading a Dangerfile, here's a summary:

// It's a JS runtime which helps you provide continuous feedback inside GitHub.

```
//
```

// You can see the docs here: http://danger.systems/js/

```
//
```

// If you want to test changes Danger, I'd recommend checking out an existing PR

// and then running the `danger pr` command.

```
//
```

// You'll need a GitHub token, you can re-use this one:

```
//
```

//  0a7d5c3cad9a6dbec2d9 9a5222cf49062a4c1ef7

```
//
```
```
// (Just remove the space)
```
```
//
```
```
// So, for example:
```
```
//
```

// `DANGER_GITHUB_API_TOKEN=[ENV_ABOVE] yarn danger pr https://github.com/facebook/react/pull/11865

const {markdown, danger, warn} = require('danger');

```
const {promisify} = require('util');
```

const glob = promisify(require('glob'));

```
const gzipSize = require('gzip-size');
```

const {readFileSync, statSync} = require('fs');

```
const BASE_DIR = 'base-build';
```
```
const HEAD_DIR = 'build';
```
```
const CRITICAL_THRESHOLD = 0.02;
```
```
const SIGNIFICANCE_THRESHOLD = 0.002;
```

const CRITICAL_ARTIFACT_PATHS = new Set([

  // We always report changes to these bundles, even if the change is

```
  // insignificant or non-existent.
```

  'oss-stable/react-dom/cjs/react-dom.production.min.js',

  'oss-experimental/react-dom/cjs/react-dom.production.min.js',

  'facebook-www/ReactDOM-prod.classic.js',

  'facebook-www/ReactDOM-prod.modern.js',

```
]);
```

const kilobyteFormatter = new Intl.NumberFormat('en', {

```
  style: 'unit',
```
```
  unit: 'kilobyte',
```
```
  minimumFractionDigits: 2,
```
```
  maximumFractionDigits: 2,
```
```
});
```
```
function kbs(bytes) {
```

  return kilobyteFormatter.format(bytes / 1000);

```
}
```

const percentFormatter = new Intl.NumberFormat('en', {

```
  style: 'percent',
```
```
  signDisplay: 'exceptZero',
```
```
  minimumFractionDigits: 2,
```
```
  maximumFractionDigits: 2,
```
```
});
```
```
function change(decimal) {
```
```
  if (Number === Infinity) {
```
```
    return 'New file';
```
```
  }
```
```
  if (decimal === -1) {
```
```
    return 'Deleted';
```
```
  }
```
```
  if (decimal < 0.0001) {
```
```
    return '=';
```
```
  }
```

  return percentFormatter.format(decimal);

```
}
```
```
const header = `
```

  | Name | +/- | Base | Current | +/- gzip | Base gzip | Current gzip |

  | ---- | --- | ---- | ------- | -------- | --------- | ------------ |`;

function row(result, baseSha, headSha) {

  const diffViewUrl = `https://react-builds.vercel.app/commits/${headSha}/files/${result.path}?compare=${baseSha}`;

```
  const rowArr = [
```

    `| [${result.path}](${diffViewUrl})`,

```
    `**${change(result.change)}**`,
```
```
    `${kbs(result.baseSize)}`,
```
```
    `${kbs(result.headSize)}`,
```
```
    `${change(result.changeGzip)}`,
```
```
    `${kbs(result.baseSizeGzip)}`,
```
```
    `${kbs(result.headSizeGzip)}`,
```
```
  ];
```
```
  return rowArr.join(' | ');
```
```
}
```
```
(async function () {
```

  // Use git locally to grab the commit which represents the place

```
  // where the branches differ
```

  const upstreamRepo = danger.github.pr.base.repo.full_name;

  if (upstreamRepo !== 'facebook/react') {

    // Exit unless we're running in the main repo

```
    return;
```
```
  }
```
```
  let headSha;
```
```
  let baseSha;
```
```
  try {
```

    headSha = String(readFileSync(HEAD_DIR + '/COMMIT_SHA')).trim();

    baseSha = String(readFileSync(BASE_DIR + '/COMMIT_SHA')).trim();

```
  } catch {
```
```
    warn(
```

      "Failed to read build artifacts. It's possible a build configuration " +

        'has changed upstream. Try pulling the latest changes from the ' +

```
        'main branch.'
```
```
    );
```
```
    return;
```
```
  }
```

  // Disable sizeBot in a Devtools Pull Request. Because that doesn't affect production bundle size.

```
  const commitFiles = [
```
```
    ...danger.git.created_files,
```
```
    ...danger.git.deleted_files,
```
```
    ...danger.git.modified_files,
```
```
  ];
```
```
  if (
```

    commitFiles.every(filename => filename.includes('packages/react-devtools'))

```
  )
```
```
    return;
```
```
  const resultsMap = new Map();
```

  // Find all the head (current) artifacts paths.

  const headArtifactPaths = await glob('**/*.js', {cwd: 'build'});

  for (const artifactPath of headArtifactPaths) {

```
    try {
```

      // This will throw if there's no matching base artifact

      const baseSize = statSync(BASE_DIR + '/' + artifactPath).size;

      const baseSizeGzip = gzipSize.fileSync(BASE_DIR + '/' + artifactPath);

      const headSize = statSync(HEAD_DIR + '/' + artifactPath).size;

      const headSizeGzip = gzipSize.fileSync(HEAD_DIR + '/' + artifactPath);

```
      resultsMap.set(artifactPath, {
```
```
        path: artifactPath,
```
```
        headSize,
```
```
        headSizeGzip,
```
```
        baseSize,
```
```
        baseSizeGzip,
```

        change: (headSize - baseSize) / baseSize,

        changeGzip: (headSizeGzip - baseSizeGzip) / baseSizeGzip,

```
      });
```
```
    } catch {
```

      // There's no matching base artifact. This is a new file.

```
      const baseSize = 0;
```
```
      const baseSizeGzip = 0;
```

      const headSize = statSync(HEAD_DIR + '/' + artifactPath).size;

      const headSizeGzip = gzipSize.fileSync(HEAD_DIR + '/' + artifactPath);

```
      resultsMap.set(artifactPath, {
```
```
        path: artifactPath,
```
```
        headSize,
```
```
        headSizeGzip,
```
```
        baseSize,
```
```
        baseSizeGzip,
```
```
        change: Infinity,
```
```
        changeGzip: Infinity,
```
```
      });
```
```
    }
```
```
  }
```

  // Check for base artifacts that were deleted in the head.

  const baseArtifactPaths = await glob('**/*.js', {cwd: 'base-build'});

  for (const artifactPath of baseArtifactPaths) {

    if (!resultsMap.has(artifactPath)) {

      const baseSize = statSync(BASE_DIR + '/' + artifactPath).size;

      const baseSizeGzip = gzipSize.fileSync(BASE_DIR + '/' + artifactPath);

```
      const headSize = 0;
```
```
      const headSizeGzip = 0;
```
```
      resultsMap.set(artifactPath, {
```
```
        path: artifactPath,
```
```
        headSize,
```
```
        headSizeGzip,
```
```
        baseSize,
```
```
        baseSizeGzip,
```
```
        change: -1,
```
```
        changeGzip: -1,
```
```
      });
```
```
    }
```
```
  }
```

  const results = Array.from(resultsMap.values());

  results.sort((a, b) => b.change - a.change);

```
  let criticalResults = [];
```

  for (const artifactPath of CRITICAL_ARTIFACT_PATHS) {

    const result = resultsMap.get(artifactPath);

```
    if (result === undefined) {
```
```
      throw new Error(
```

        'Missing expected bundle. If this was an intentional change to the ' +

          'build configuration, update Dangerfile.js accordingly: ' +

```
          artifactPath
```
```
      );
```
```
    }
```

    criticalResults.push(row(result, baseSha, headSha));

```
  }
```
```
  let significantResults = [];
```
```
  for (const result of results) {
```

    // If result exceeds critical threshold, add to top section.

```
    if (
```

      (result.change > CRITICAL_THRESHOLD ||

        0 - result.change > CRITICAL_THRESHOLD ||

```
        // New file
```
```
        result.change === Infinity ||
```
```
        // Deleted file
```
```
        result.change === -1) &&
```

      // Skip critical artifacts. We added those earlier, in a fixed order.

      !CRITICAL_ARTIFACT_PATHS.has(result.path)

```
    ) {
```

      criticalResults.push(row(result, baseSha, headSha));

```
    }
```

    // Do the same for results that exceed the significant threshold. These

    // will go into the bottom, collapsed section. Intentionally including

    // critical artifacts in this section, too.

```
    if (
```

      result.change > SIGNIFICANCE_THRESHOLD ||

      0 - result.change > SIGNIFICANCE_THRESHOLD ||

```
      result.change === Infinity ||
```
```
      result.change === -1
```
```
    ) {
```

      significantResults.push(row(result, baseSha, headSha));

```
    }
```
```
  }
```
```
  markdown(`
```
```
Comparing: ${baseSha}...${headSha}
```
```
## Critical size changes
```

Includes critical production bundles, as well as any change greater than ${

```
    CRITICAL_THRESHOLD * 100
```
```
  }%:
```
```
${header}
```
```
${criticalResults.join('\n')}
```
```
## Significant size changes
```

Includes any change greater than ${SIGNIFICANCE_THRESHOLD * 100}%:

```
${
```
```
  significantResults.length > 0
```
```
    ? `
```
```
<details>
```
```
<summary>Expand to show</summary>
```
```
${header}
```
```
${significantResults.join('\n')}
```
```
</details>
```
```
`
```
```
    : '(No significant changes)'
```
```
}
```
```
`);
```
```
})();
```