Function handler

packages/vite/src/node/plugins/define.ts:138–165

(code, id)

    transform: {
      handler(code, id) {
        if (this.environment.config.consumer === 'client') {
          // for dev we inject actual global defines in the vite client to
          // avoid the transform cost. see the `clientInjection` and
          // `importAnalysis` plugin.
          return
        }

        if (
          // exclude html, css and static assets for performance
          isHTMLRequest(id) ||
          isCSSRequest(id) ||
          isNonJsRequest(id) ||
          config.assetsInclude(id)
        ) {
          return
        }

        const [define, pattern] = getPattern(this.environment)
        if (!pattern) return

        // Check if our code needs any replacements before running esbuild
        pattern.lastIndex = 0
        if (!pattern.test(code)) return

        const result = replaceDefine(this.environment, code, id, define)
        return result
      },
    },
  }
}