Function transform

packages/vite/src/node/plugins/esbuild.ts:311–335

(code, id)

      server = _server
    },
    async transform(code, id) {
      if (filter(id) || filter(cleanUrl(id))) {
        const result = await transformWithEsbuild(
          code,
          id,
          transformOptions,
          undefined,
          config,
          server?.watcher,
        )
        if (result.warnings.length) {
          result.warnings.forEach((m) => {
            this.warn(prettifyMessage(m, code))
          })
        }
        if (jsxInject && jsxExtensionsRE.test(id)) {
          result.code = jsxInject + ';' + result.code
        }
        return {
          code: result.code,
          map: result.map,
          moduleType: 'js',
        }
      }
    },
  }
}