Function resolveId

packages/vite/src/node/plugins/preAlias.ts:34–86

(id, importer, options)

      return !isDepOptimizationDisabled(environment.config.optimizeDeps)
    },
    async resolveId(id, importer, options) {
      const environment = this.environment as DevEnvironment
      const ssr = environment.config.consumer === 'server'
      const depsOptimizer = environment.depsOptimizer
      if (
        importer &&
        depsOptimizer &&
        bareImportRE.test(id) &&
        !options.scan &&
        id !== '@vite/client' &&
        id !== '@vite/env'
      ) {
        if (findPatterns.find((pattern) => matches(pattern, id))) {
          const optimizedId = await tryOptimizedResolve(
            depsOptimizer,
            id,
            importer,
            config.resolve.preserveSymlinks,
            config.packageCache,
          )
          if (optimizedId) {
            return optimizedId // aliased dep already optimized
          }
          if (depsOptimizer.options.noDiscovery) {
            return
          }
          const resolved = await this.resolve(id, importer, options)
          if (resolved && !depsOptimizer.isOptimizedDepFile(resolved.id)) {
            const optimizeDeps = depsOptimizer.options
            const resolvedId = cleanUrl(resolved.id)
            const isVirtual = resolvedId === id || resolvedId.includes('\0')
            if (
              !isVirtual &&
              fs.existsSync(resolvedId) &&
              !moduleListContains(optimizeDeps.exclude, id) &&
              path.isAbsolute(resolvedId) &&
              (isInNodeModules(resolvedId) ||
                optimizeDeps.include?.includes(id)) &&
              isOptimizable(resolvedId, optimizeDeps) &&
              (!ssr || optimizeAliasReplacementForSSR(resolvedId, optimizeDeps))
            ) {
              // aliased dep has not yet been optimized
              const optimizedInfo = depsOptimizer!.registerMissingImport(
                id,
                resolvedId,
              )
              return { id: depsOptimizer!.getOptimizedDepId(optimizedInfo) }
            }
          }
          return resolved
        }
      }
    },
  }
}