Issues with the handling of exports maps in package.json

[sventschui]

Describe the bug

Vite seems to have troubles to correctly resolve node modules that have exports defined in their package.json. This issue includes a repro for @urql/preact but I found the same issues with @urql/core and wonka. Dropping the exports from the package.jsons helped in all cases.

EDIT: Only applicable to node 13, works with node 12

Reproduction

Add the following import to a basic vite setup:

import { createClient } from '@urql/preact';

(See https://github.com/sventschui/vite-mjs-repro/tree/urql)

System Info

• required vite version: 0.14.2
• required Operating System: OS X
• required Node version: 13.12.0

Logs (Optional if provided reproduction)

  vite:resolve (redirect) @urql/preact -> dist/urql-preact.mjs +4ms
[vite] Error while resolving node_modules with id "@urql/preact/dist/urql-preact.mjs":
Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './dist/urql-preact.mjs' is not defined by "exports" in xxx/vite-mjs-repro/node_modules/@urql/preact/package.json
    at applyExports (internal/modules/cjs/loader.js:524:9)
    at resolveExports (internal/modules/cjs/loader.js:541:12)
    at Function.Module._findPath (internal/modules/cjs/loader.js:661:22)
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:963:27)
    at resolveFileName (xxx/vite-mjs-repro/node_modules/vite/node_modules/resolve-from/index.js:29:39)
    at resolveFrom (xxx/vite-mjs-repro/node_modules/vite/node_modules/resolve-from/index.js:43:9)
    at Object.module.exports [as default] (xxx/vite-mjs-repro/node_modules/vite/node_modules/resolve-from/index.js:46:47)
    at xxx/vite-mjs-repro/node_modules/vite/dist/server/serverPluginModuleResolve.js:79:48
    at async xxx/vite-mjs-repro/node_modules/vite/dist/server/serverPluginModuleRewrite.js:41:9 {
  code: 'ERR_PACKAGE_PATH_NOT_EXPORTED'

[yyx990803]

closed via e49742e