detectPolyfills() — vite Function Reference

Architecture documentation for the detectPolyfills() function in index.ts from the vite codebase.

Function typescript PluginSystem LegacySupport calls 1 called by 1

Entity Profile

PluginSystem→ LegacySupport→ detectPolyfills() — vite Function Reference

Dependency Diagram

graph TD
  8f96a660_631f_d882_8813_44cfe1cdb28f["detectPolyfills()"]
  9776ecb6_00c0_b3b9_b3f7_177fedabeacc["index.ts"]
  8f96a660_631f_d882_8813_44cfe1cdb28f -->|defined in| 9776ecb6_00c0_b3b9_b3f7_177fedabeacc
  cf21e8d8_cce6_30a7_7732_696ed5cdf103["viteLegacyPlugin()"]
  cf21e8d8_cce6_30a7_7732_696ed5cdf103 -->|calls| 8f96a660_631f_d882_8813_44cfe1cdb28f
  b52618ce_8781_f4f2_b33b_cd2b4ed2b715["loadBabel()"]
  8f96a660_631f_d882_8813_44cfe1cdb28f -->|calls| b52618ce_8781_f4f2_b33b_cd2b4ed2b715
  style 8f96a660_631f_d882_8813_44cfe1cdb28f fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/plugin-legacy/src/index.ts lines 788–832

export async function detectPolyfills(
  code: string,
  targets: any,
  assumptions: Record<string, boolean>,
  list: Set<string>,
): Promise<void> {
  const babel = await loadBabel()
  const result = babel.transform(code, {
    ast: true,
    code: false,
    babelrc: false,
    configFile: false,
    compact: false,
    targets,
    assumptions,
    browserslistConfigFile: false,
    plugins: [
      [
        (await import('babel-plugin-polyfill-corejs3')).default,
        {
          method: 'usage-global',
          version: _require('core-js/package.json').version,
          shippedProposals: true,
        },
      ],
      [
        (await import('babel-plugin-polyfill-regenerator')).default,
        {
          method: 'usage-global',
        },
      ],
    ],
  })
  for (const node of result!.ast!.program.body) {
    if (node.type === 'ImportDeclaration') {
      const source = node.source.value
      if (
        source.startsWith('core-js/') ||
        source.startsWith('regenerator-runtime/')
      ) {
        list.add(source)
      }
    }
  }
}