What is node.js referring to when showing a server startup error?

Question

Node.js

I can't find on the internet what's wrong with the experimental import function. 100% error text will not be enough, so I expect questions about what else to show from the configs.

"C:\Program Files\nodejs\node.exe" --experimental-json-modules C:\git\fast-start-react\src\appExpress.js
Console output is saving to: C:\git\fast-start-react\logs\server-node-log.log
(node:12276) ExperimentalWarning: The ESM module loader is experimental.
internal/modules/esm/module_job.js:111
          const namedImports = StringPrototypeMatch(importStatement, /{.*}/)[0];
                                                                            ^

TypeError: Cannot read property '0' of null
    at ModuleJob._instantiate (internal/modules/esm/module_job.js:111:77)
    at async ModuleJob.run (internal/modules/esm/module_job.js:136:20)
    at async Loader.import (internal/modules/esm/loader.js:179:24)

Process finished with exit code 1

Answer 1

TypeError: Cannot read property '0' of null
in this case, it says that it cannot read the '0' property of null
, that is,
StringPrototypeMatch(importStatement, /{.*}/)instead of an array (or possibly instead of an object or even a string), it gives you null
in the simplest case, you need to add a check for the presence of the desired data type. like this

const match =  StringPrototypeMatch(importStatement, /{.*}/);
if( !match ) {
   return; // сопоставлений не найдено, дальшейшие действия не имеют смысла
}
const namedImports = match[0];