My project is created using angular cli [ version - 6.1.3 ].
I installed npm module - is-reachable and used it in my code as -
const isReachable = require('is-reachable');
appDetailsFromJson.forEach(app => {
isReachable(app.server).then(reachable => {
console.log('Hey --> ',reachable);
//=> true
});
However, on running the project it throws the exception - error TS2304: Cannot find name 'require'.
What is the root cause for this & what is the correct way to import a library in angular 6 ?
From the NPM page of isReachable it says (my emphasis):
Works in Node.js and the browser (with browserify).
This means that it is unlikely to work natively in an Angular application as the Angular CLI uses webpack and the standard typescript compiler (rather than browserify) to resolve imports and package dependencies.
In general, imports in Angular are standard ES6-style 'import' statements, e.g.:
import { isReachable } from 'is-reachable';
... or ...
import * as isReachable from 'is-reachable';
If is-reachable itself does not use any further require() statements, this may work, but if it uses require within its own code to bring in its dependencies, you would be in for a lot of difficulty in getting it to work at all - and it would almost certainly be better to find a different way to meet your requirement.
Related
I am trying to follow this tutorial using nodejs and express: https://pusher.com/docs/beams/reference/web/#npm-yarn
First I did: npm install #pusher/push-notifications-web before adding the code.
But when I add this code in the index.js file:
import * as PusherPushNotifications from "#pusher/push-notifications-web";
const beamsClient = new PusherPushNotifications.Client({
instanceId: "<YOUR_INSTANCE_ID_HERE>",
});
beamsClient.start().then(() => {
// Build something beatiful 🌈
});
I get this error:
SyntaxError: Cannot use import statement outside a module
It's also not very clear to me from the tutorial if the code has to be in the frontend or the backend. I tried both but got the same result.
How can I fix this problem?
The error is caused by the fact that you're trying to use ES module specific features in a regular CommonJS file (the default behavior in Node.js). However, what you're looking at is the Web SDK for Pusher which won't help you achieve your goals.
You need the server SDK for Node.js - https://pusher.com/docs/beams/reference/server-sdk-node/.
Verify that you have the latest version of Node.js installed and you have 2 ways of fixing that
Set "type" field with a value of "module" in package.json. This will ensure that all .js and .mjs files are interpreted as ES modules.
// package.json
{
"type": "module"
}
Use .mjs as file extension instead of .js.
I try to implement e2e tests in a simple NestJS project (generate with 'nest new' command, add some dependencies and config Project here), the existing tests (not e2e ones) run properly (all modules are resolved).
But, when I execute the default app.e2e-spec.ts (generated by nest cli), I got this following error
Cannot find module 'cls-hooked' from 'src/common/http-context.ts'
The only difference between working and broke version is the test file selected (in the jest config)
testRegex: '.e2e-spec.ts$', // Doesn't work
// testRegex: '.*\\.spec\\.ts$', // Work
The module resolution with TS works well when I look for the trace of tsc --traceResolution
The project is running correctly and works well. Then, globally, Jest & TS are well configured
The error is the same when I use a relative path
// src/common/http-context.ts
// import * as cls from 'cls-hooked';
import * as cls from '../../node_modules/#types/cls-hooked';
When I explicitly set the path to module
moduleNameMapper: {
'cls-hooked': '<rootDir>/node_modules/#types/cls-hooked/index.d.ts',
},
The error suggest an interoperability issue
Jest encountered an unexpected token
This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
Here's what you can do:
• If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/en/ecmascript-modules for how to enable it.
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/en/configuration.html
Details:
C:\Users\taquet_p\Sources\nestJsGrapQLTest\test-jest-imports\node_modules\#types\cls-hooked\index.d.ts:8
import { EventEmitter } from 'events';
^^^^^^
SyntaxError: Cannot use import statement outside a module
> 1 | import * as cls from 'cls-hooked';
| ^
2 |
3 | export class HttpContext {
4 |
at Runtime.createScriptFromCode (node_modules/jest-runtime/build/index.js:1350:14)
at Object.<anonymous> (src/common/http-context.ts:1:1)
I tried to configure support for ECMAScript module and other things in tsconfig.json and jest.config.js
I check most of SOF questions about Cannot find module within Jest
I have no more ideas to googling about.
Do anyone has a solution ? A suggestion ?
The github repo provide the atomic project to reproduce the issue directly. Just pull, npm install & run test (the jest config file is a bit dirty :-) )
I'm new with configuring stuff with Rollup, I'm trying to configure a node CLI app to be bundled in a single cli.bundle.js file that would be executable with a simple node cli.bundle.js without needing to npm install anything before.
On a side note, we already have succeed in doing so with zeit/pkg, but we would rather note have all the nodejs executable bundled inside, so we are trying work with rollup instead of pkg.
The problem we encounter is that when going through the different node_modules of the application, rollup.js crash with error:
[!] Error: Identifier 'Reader' has already been declared
../../common/js-common/node_modules/fstream/lib/file-reader.js (7:4)
5: var fs = require("graceful-fs")
6: , fstream = require("../fstream.js")
7: , Reader = fstream.Reader
^
8: , inherits = require("inherits")
9: , mkdir = require("mkdirp")
Error: Identifier 'Reader' has already been declared
at error (/home/.../src/external-data/external-data-etl/node_modules/rollup/dist/shared/node-entry.js:5400:30)
at Module.error (/home/.../src/external-data/external-data-etl/node_modules/rollup/dist/shared/node-entry.js:9820:16)
at tryParse (/home/.../src/external-data/external-data-etl/node_modules/rollup/dist/shared/node-entry.js:9713:23)
at Module.setSource (/home/.../src/external-data/external-data-etl/node_modules/rollup/dist/shared/node-entry.js:10076:33)
at Promise.resolve.catch.then.then.then (/home/.../src/external-data/external-data-etl/node_modules/rollup/dist/shared/node-entry.js:12362:20)
While looking for this error with rollup, it seems people were having it more at execution time than at bundle time, so I have no clue of what I can do. This duplicated identifier is in a 3rd party code I don't control :(
Here is my rollup.config.js
Edit: I tried with the new #rollup/plugins to see if there were a fix in them, but I have still the same issue.
import commonjs from '#rollup/plugin-commonjs';
import resolve from '#rollup/plugin-node-resolve';
import json from '#rollup/plugin-json';
export default {
input: 'dist/index.js',
output: {
format: 'cjs',
file: './cli.bundle.js'
},
plugins: [
commonjs(),
resolve(),
json() // asked and added when parsing 'got' package imported by 'download' package
]
};
And our building process is :
transpile from typescript (src) to js (dist) with tsc
bundle (dist) app into single runnable file
We would rather not include babel or typescript plugin to transpile, to stay independant, and certainly the (dist) app is enough (as it was enough for zeit/pkg).
Is there something we are doing wrong ?
The Problem is your dependency it is not coded in the right way you will need to correct the code error they did.
I try to import a node module inside an Angular 8 web worker, but get an compile error 'Cannot find module'. Anyone know how to solve this?
I created a new worker inside my electron project with ng generate web-worker app, like described in the above mentioned ng documentation.
All works fine until i add some import like path or fs-extra e.g.:
/// <reference lib="webworker" />
import * as path from 'path';
addEventListener('message', ({ data }) => {
console.log(path.resolve('/'))
const response = `worker response to ${data}`;
postMessage(response);
});
This import works fine in any other ts component but inside the web worker i get a compile error with this message e.g.
Error: app/app.worker.ts:3:23 - error TS2307: Cannot find module 'path'.
How can i fix this? Maybe i need some additional parameter in the generated tsconfig.worker.json?
To reproduce the error, run:
$ git clone https://github.com/hoefling/stackoverflow-57774039
$ cd stackoverflow-57774039
$ yarn build
Or check out the project's build log on Travis.
Note:
1) I only found this as a similar problem, but the answer handles only custom modules.
2) I tested the same import with a minimal electron seed which uses web workers and it worked, but this example uses plain java script without angular.
1. TypeScript error
As you've noticed the first error is a TypeScript error. Looking at the tsconfig.worker.json I've found that it sets types to an empty array:
{
"compilerOptions": {
"types": [],
// ...
}
// ...
}
Specifying types turns off the automatic inclusion of #types packages. Which is a problem in this case because path has its type definitions in #types/node.
So let's fix that by explicitly adding node to the types array:
{
"compilerOptions": {
"types": [
"node"
],
// ...
}
// ...
}
This fixes the TypeScript error, however trying to build again we're greeted with a very similar error. This time from Webpack directly.
2. Webpack error
ERROR in ./src/app/app.worker.ts (./node_modules/worker-plugin/dist/loader.js!./src/app/app.worker.ts)
Module build failed (from ./node_modules/worker-plugin/dist/loader.js):
ModuleNotFoundError: Module not found: Error: Can't resolve 'path' in './src/app'
To figure this one out we need to dig quite a lot deeper...
Why it works everywhere else
First it's important to understand why importing path works in all the other modules. Webpack has the concept of targets (web, node, etc). Webpack uses this target to decide which default options and plugins to use.
Ordinarily the target of a Angular application using #angular-devkit/build-angular:browser would be web. However in your case, the postinstall:electron script actually patches node_modules to change that:
postinstall.js (parts omitted for brevity)
const f_angular = 'node_modules/#angular-devkit/build-angular/src/angular-cli-files/models/webpack-configs/browser.js';
fs.readFile(f_angular, 'utf8', function (err, data) {
var result = data.replace(/target: "electron-renderer",/g, '');
var result = result.replace(/target: "web",/g, '');
var result = result.replace(/return \{/g, 'return {target: "electron-renderer",');
fs.writeFile(f_angular, result, 'utf8');
});
The target electron-renderer is treated by Webpack similarily to node. Especially interesting for us: It adds the NodeTargetPlugin by default.
What does that plugin do, you wonder? It adds all known built in Node.js modules as externals. When building the application, Webpack will not attempt to bundle externals. Instead they are resolved using require at runtime. This is what makes importing path work, even though it's not installed as a module known to Webpack.
Why it doesn't work for the worker
The worker is compiled separately using the WorkerPlugin. In their documentation they state:
By default, WorkerPlugin doesn't run any of your configured Webpack plugins when bundling worker code - this avoids running things like html-webpack-plugin twice. For cases where it's necessary to apply a plugin to Worker code, use the plugins option.
Looking at the usage of WorkerPlugin deep within #angular-devkit we see the following:
#angular-devkit/src/angular-cli-files/models/webpack-configs/worker.js (simplified)
new WorkerPlugin({
globalObject: false,
plugins: [
getTypescriptWorkerPlugin(wco, workerTsConfigPath)
],
})
As we can see it uses the plugins option, but only for a single plugin which is responsible for the TypeScript compilation. This way the default plugins, configured by Webpack, including NodeTargetPlugin get lost and are not used for the worker.
Solution
To fix this we have to modify the Webpack config. And to do that we'll use #angular-builders/custom-webpack. Go ahead and install that package.
Next, open angular.json and update projects > angular-electron > architect > build:
"build": {
"builder": "#angular-builders/custom-webpack:browser",
"options": {
"customWebpackConfig": {
"path": "./extra-webpack.config.js"
}
// existing options
}
}
Repeat the same for serve.
Now, create extra-webpack.config.js in the same directory as angular.json:
const WorkerPlugin = require('worker-plugin');
const NodeTargetPlugin = require('webpack/lib/node/NodeTargetPlugin');
module.exports = (config, options) => {
let workerPlugin = config.plugins.find(p => p instanceof WorkerPlugin);
if (workerPlugin) {
workerPlugin.options.plugins.push(new NodeTargetPlugin());
}
return config;
};
The file exports a function which will be called by #angular-builders/custom-webpack with the existing Webpack config object. We can then search all plugins for an instance of the WorkerPlugin and patch its options adding the NodeTargetPlugin.
I have a typescript project which has uses one of our node modules which normally runs in our front-end. We are now looking to use this module in node on our server.
The module uses es6 import syntax import { props } from 'module/file'
When I include a ref in typescript using either of the following methods
import { props } from 'module/file';
var props = require('module/file');
I get the following error from typescript
unexpected token 'import'
(function (exports, require, module, __filename, __dirname) { import
It's a big job to re-write the module, and I've tried using babel with babel-plugin-dynamic-import-node, as well as SystemJS.
The problem with these systems is that they are all asynchronous, so I can't import the module in the standard fashion, so I would need to do a whole bunch of re-write when we get to the point that I can use import natively in node.js.
I can't be the first person to have this issue, but I can't seem to find a working solution.
--------------- update with set-up -------------
In response to #DanielKhoroshko's response. The original module I am trying to import is normally packaged by webpack in order to use on the front-end. I am now trying to use this same module both server-side and in the front-end (via webpack on the front-end) without re-writing the imports to use require and without running webpack to bundle the js to use on the server.
To be clear, the original module is written in JS, our service which is trying to use this module is written in typescript and transpiled. When the typescript tries to require the old module which uses import, it is at this point that we are running into the issue.
------------------ some progress ---------------------------
I've made some progress by creating a file in my imported module which uses babel in node.js to transpile the es6 code into commonJS modules.
I've done this via
var babel = require("babel-core")
var store = babel.transformFileSync(__dirname + '/store.js', {
plugins: ["transform-es2015-modules-commonjs"]
});
module.exports = {
store: store.code
}
I can now get the store in my new node.js project. However, the submodules within the store.js file are not included in the export.
So where in my module, it says
import activities from './reducers/activities';
I now get an error
Cannot find module './reducers/activities'
How can I get babel to do a deep traversal to include the sub-directories?
unexpected token 'import' means you are running es-modules code in environment that doesn't support import/export commands. If you are writing you code in TypeScript it's important to transpile it first before building for the browser or use ts-node to run it server-side.
If you are using webpack there are loaders ts-loader and awesome-typescript-loader
What is your setup?
To describe the module you would need to create an activities.d.ts file in the same folder where the js-version (I understood it is called activities.js and containers a reducer) resides with the following (approx.):
import { Reducer } from 'redux';
export const activities: Reducer<any>;
#Daniel Khoroshko was right in many ways, I ended up finding #std/esm which lets you import es6 modules and worked find for fetching the included imports as well.
var babel = require('babel-register')({
presets: ["env"]
});
require = require('#std/esm')(module);
var store = require('ayvri-viewer/src/store');
exports.default = {
store: store
}
I had to run babel to get a consistent build from es6 to node compatible es5