“类型错误： <class> 不是构造函数”，将其导出到npm包的index.js中

Question

I created the npm package tcx-file-class which handles tcx files the way I want to analyse the data afterwards. So it creates (among others) an Activity class.

Activity class exported from the package in the index.ts file in this way:

import TcxFile from "./dist/classes/tcxFile"
import Activity from "./dist/classes/activity"
//other imports here

export { TcxFile, Activity,
       //other classes 
       }

So when I try to import the class from the package index file like this:

import {Activity} from 'tcx-file-class'

const a = new Activity();

I get the following error:

const a = new tcx_file_class_1.Activity();
      ^

TypeError: tcx_file_class_1.Activity is not a constructor
at Object.<anonymous> (/Users/stratis/Desktop/development/production/ts/events/dist/index.js:11:11)
at Module._compile (internal/modules/cjs/loader.js:678:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:689:10)
at Module.load (internal/modules/cjs/loader.js:589:32)
at tryModuleLoad (internal/modules/cjs/loader.js:528:12)
at Function.Module._load (internal/modules/cjs/loader.js:520:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:719:10)
at startup (internal/bootstrap/node.js:228:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:575:3)

but when I import the class from the package class file, like this:

import {Activity} from '../node_modules/tcx-file-class/dist/classes/activity'

const a = new Activity();

everything work's just fine.

So, I guess that the exporting procedure is the problem but I can't spot the error. Any suggestions?

Answer 1

It looks to me (and as CertainPerformance pointed out in the comments) that You are exporting Activity as a named export like

export { Activity } and not export default Activity

You will need to change your index.ts file's imports to

import {TcxFile} from "./dist/classes/tcxFile"
import {Activity} from "./dist/classes/activity"

to be able to use named imports.