I have the following reference import { STORE } from "../data/store"; It's part of a react project and works as expected.
However I need to run some code separately over STORE and accessed it the same way as it is in the react project, but ran via ts-node. When I try to access STORE by let data = STORE[videoId].labels;, with videoId set as "home" I get TypeError: Cannot read property 'home' of undefined.
Might anyone know what I'm missing --- must be something specific to ts-node...? Thanks!
In case someone arrives on this page because of imports issue, like I did, here's what my problem was:
I had three files : index.ts, File.json and File.ts
In index.ts:
import { thing } from "./File";
was working well in VS Code: I had auto-completion for thing and everything.
But when running ts-node index.ts, thing was undefined!
When I remembered that I had the json file, I just renamed File.ts to File.module.ts and changed the import to:
import { thing } from "./File.module";
and it was sorted.
It sounds like the property STORE is undefined..
If you change import { STORE } from "../data/store"; to import * as STORE from "../data/store" does it work?
Related
trying to use passport-custom and the very first line, from pseudocode at npmjs, errors out:
import passportCustom from 'passport-custom';
The is no default import in index.js when I open it up under node_modules/passport-custom/lib
I must be missing something fundamental here, don't know what though
Try to use CommonJS const passportCustom = require("passport-custom") You probably have older version of Node.js which does not support ES6 modules.
There is no default export. So you will have to name the items you want to import (put them in curly braces).
//Example:
import { a,b,c,d} from 'youPackage';
//Your case:
import { passportCustom } from 'passport-custom';
Above are called named imports. When a package exports one item by default using: export default passportCustom ;, you could have use your code. You can access the code of the package to have a look for yourself.
Is it possible to get data from server side's config file on client by getServersideProps() in Next.js? How to put data in props? Or how to get it on client in other way?
I have tried publicRuntimeConfig in next.config.js, but it is undefined and I don't know why...
It's hard to tell exactly what's going on but I have one idea from experience: You need to make sure you're calling nextJSApp.prepare() before any modules using next/config are included.
As an example,
// SomeComponent.tsx
import { getConfig } from 'next/config'
const config = getConfig()
export interface X { ... }
// server.ts
import { X } from './SomeComponent'
app.prepare().then(...)
This fails because module are loaded first and the config hasn't been initialized until app.prepare has been completed.
The solution for this is to either use TypeScript's import(...) syntax if you just need a type or use node's require for dynamic resolution during runtime.
I'm trying to access the decode() method in the jsQR module.
I found an example that called decode() directly but that was from an HTML file, not nodejs.
In visual code I see this...
I know that the default export is defined in index.d.ts but is there anyway of importing the other classes/functions on the rest of the dist folder?
I've tried to import using require("jsqr/decoder") and require("jsqr/decoder/decode") to no avail.
EDIT
To be clear, I don't want jsQR, the default export. That deals with images. I'm trying to explicitly call the decode() method in the pic which accepts a BitMatrix
There are no limitations in what you can require from node_modules. So, with your case it should look like:
TypeScript\ESM Modules:
import { decode } from 'jsqr/dist/decoder/decoder';
CommonJS:
const { decode } = require('jsqr/dist/decoder/decoder');
UPD: If you take a look into dist folder for jsqr package, you can find that there are only d.ts files. Which means that you can not import it from there.
But, you can find an actual export of the module here:
Which means that you should able to import it from jsqr:
const { decode } = require('jsqr');
I have a simple application that is imported from webpack. The imported project exports a class like this...
export class BaseApp{...}
import { BaseApp } from "./MyClass"
import OtherThing from "./Other"
....
export { BaseApp, OtherThing }
Next I try to extend it in another node/express project...
import { BaseApp } from "#mine/util";
export class FullApp extends BaseApp{... }
I get...
class FullApp extends _mine_util__WEBPACK_IMPORTED_MODULE_0__["BaseA
pp"]{
^
TypeError: Class extends value undefined is not a constructor or null
How do I extend a class I am importing from Webpack?
Update here is an example project that demonstrates the issue...
https://github.com/jrgleason/simple-webpack-node
Impossible to say for certain when there is clearly much more to the source. If anyone else sees this error, the first thing to look for is circular dependencies: a file depends on some other file that (likely indirectly) depends on the first. JS must start somewhere, will not be able to ensure that a file is defined at the time that another file needs it, and will not try to go back and fill in the blanks later.
If you have more than a couple import / require statements, I recommend periodically running a checker like Madge to find and optionally visualize any loops before they become hard to undo.
npm i --saveDev madge
node node_modules/madge/bin/cli.js --warning --circular --extensions js ./
I am having strange issues with Typescript when I import things from a file which exports them. Sometimes I will export a function, then import it to another file, then I use the function and it is not a function anymore. When I define the function in the same file, all of a sudden the function is a function?!?!?
Why would a function stop being a function when it is exported? I have had similar problems with classes too.
The hard part of this issue is I can't recreate a simple example because it only happens when I am using some kind of higher level package.
For example, I had a similar issue with sequelize-typescript here: my github issue with typescript-sequelize
Below is some codes showing off the basic issue I'm having with one of the decorators from InversifyJS.
container.ts
import {fluentProvide} from "inversify-binding-decorators";
export const provideSingleton = (identifier: any) => {
return fluentProvide(identifier)
.inSingletonScope()
.done(true);
};
test.service.ts
import {provideSingleton} from './container'
#provideSingleton(TYPES.TEST)
export default class TestService {}
The strangest thing is when I put the provideSingleton in the same file as the TestService, everything works!?!?!
Basically to recreate the issue, simply follow the example from here: inversify-binding-decorators - Using #provideFluent multiple times. However there is an issue with the example, so please see this issue: fluentProvide example needed. The above provideSingleton reflects the changes from that issue. Then you simply import the provideSingleton function from another file instead of defining it in the same like in the example.
Can anyone explain to me what I'm missing? Why oh why would certain exported items not bee seen as the type they are? Is there a step I'm not seeing that NodeJS takes to make the item actually exported and therefore different? Can I force the function to resolve as a function so it can be used as such?
ENV:
NodeJS: 10.9.0
Typescript: 3.0.1
Mac: 10.13.16
So it looks like you can get issues like this when NodeJS can't handle a recursive import. I'm not exactly sure how to check you are getting this error other than your symptoms are like what I stated above. Basically the recursion caused my function to not load and therefore undefined is not a function.
It would be easy to notice if you had code like so:
a.ts
import B from './b';
export default class A extends B {}
b.ts
import A from './a';
export default class B extends A {}
In my case, I think my function provideSingleton did not like the file I put it in because of some conflicting code in the file, which all I had was:
import {Container} from 'inversify';
import "reflect-metadata";
import {fluentProvide} from "inversify-binding-decorators";
const container = new Container();
function ProvideSingleton(identifier: any) {
return fluentProvide(identifier)
.inSingletonScope()
.done(true);
}
export {container, ProvideSingleton}
In the end, if this issue comes up, try another file for your function and pay good attention to how the order of the loading happens. Although NodeJS handles recursive imports most of the time, you can still trip it out.