My project is suddenly having a build error. My current repo still has no problem, it only happens when I clone the repo to a new folder and install the package again then do npm run build.
So I am so scared to update the package right now...
I checked the merge history, I don't think any code merge should cause this issue..
Here is the error message I got:
$ npm run build
> container-client#2.32.0 build I:\ds\projects\new\container-service\client
> craco build
Creating an optimized production build...
Failed to compile.
I:/ds/projects/new/container-service/client/src/views/add-application/AddApplicationPage.tsx
TypeScript error in I:/ds/projects/new/container-service/client/src/views/add-application/AddApplicationPage.tsx(4,25):
Could not find a declaration file for module 'history'. 'I:/ds/projects/new/container-service/client/node_modules/history/index.js' implicitly has an 'any' type.
If the 'history' package actually exposes this module, consider sending a pull request to amend 'https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/history` TS7016
2 | import './_index.scss';
3 | import store from '../../store';
> 4 | import { History } from 'history';
| ^
This is the package.json:
{
"private": false,
"dependencies": {
"axios": "^0.19.2",
"bootstrap": "^4.6.0",
"history": "^4.10.1",
"identity-obj-proxy": "^3.0.0",
"react": "~17.0.1",
"react-app-polyfill": "~2.0.0",
"react-dom": "~17.0.1",
"react-router-dom": "~5.2.0"
},
Looks like the library "history" is causing the problem.
I tried:
delete the node_module --> npm install --> npm run build --> same error
clone the project again --> npm install --> npm run build --> same error
clone the older version of the project --> npm install --> npm run build --> same error
Nothing seems to work.
Looks like the new history needs a dependency library #types/history. I did a npm i #types/history#4.7.9 and then did a npm i again. This fixed my problem.
the problem seems to be from the history package that you are using
Could not find a declaration file for module 'history'.
try installing types for the package
npm i #types/history
if that didn't work, then change the import to require
const history = require("history")
update
the #types/history is deprecated and since version 5 of history, the type declarations are provided inside the package itself.
updating the package should fix the issue:
npm install history#latest
Assuming its as common package you would install your package and the type declarations
npm install history
npm install --save-dev #types/history
and include the types in your project within the tsconfig compilerOptions -
typeRoots for where the compiler needs to look
types - the actual library names that can be found in typeRoots
"typeRoots": [
"./node_modules/#types"
],
"types": ["history"]
I've got an ApolloServer project that's giving me trouble, so I thought I might update it and ran into issues when using the latest Babel. My "index.js" is:
require('dotenv').config()
import {startServer} from './server'
startServer()
And when I run it I get the error
SyntaxError: Cannot use import statement outside a module
First I tried doing things to convince TPTB* that this was a module (with no success). So I changed the "import" to a "require" and this worked.
But now I have about two dozen "imports" in other files giving me the same error.
*I'm sure the root of my problem is that I'm not even sure what's complaining about the issue. I sort of assumed it was Babel 7 (since I'm coming from Babel 6 and I had to change the presets) but I'm not 100% sure.
Most of what I've found for solutions don't seem to apply to straight Node. Like this one here:
ES6 module Import giving "Uncaught SyntaxError: Unexpected identifier"
Says it was resolved by adding "type=module" but this would typically go in the HTML, of which I have none. I've also tried using my project's old presets:
"presets": ["es2015", "stage-2"],
"plugins": []
But that gets me another error: "Error: Plugin/Preset files are not allowed to export objects, only functions."
Here are the dependencies I started with:
"dependencies": {
"#babel/polyfill": "^7.6.0",
"apollo-link-error": "^1.1.12",
"apollo-link-http": "^1.5.16",
"apollo-server": "^2.9.6",
"babel-preset-es2015": "^6.24.1",
Verify that you have the latest version of Node.js installed (or, at least 13.2.0+). Then do one of the following, as described in the documentation:
Option 1
In the nearest parent package.json file, add the top-level "type" field with a value of "module". This will ensure that all .js and .mjs files are interpreted as ES modules. You can interpret individual files as CommonJS by using the .cjs extension.
// package.json
{
"type": "module"
}
Option 2
Explicitly name files with the .mjs extension. All other files, such as .js will be interpreted as CommonJS, which is the default if type is not defined in package.json.
If anyone is running into this issue with TypeScript, the key to solving it for me was changing
"target": "esnext",
"module": "esnext",
to
"target": "esnext",
"module": "commonjs",
In my tsconfig.json. I was under the impression "esnext" was the "best", but that was just a mistake.
For those who were as confused as I was when reading the answers, in your package.json file, add
"type": "module"
in the upper level as show below:
{
"name": "my-app",
"version": "0.0.0",
"type": "module",
"scripts": { ...
},
...
}
According to the official documentation:
import statements are permitted only in ES modules. For similar functionality in CommonJS, see import().
To make Node.js treat your file as an ES module, you need to (Enabling):
add "type": "module" to package.json
add "--experimental-modules" flag to the Node.js call
I ran into the same issue and it's even worse: I needed both "import" and "require"
Some newer ES6 modules works only with import.
Some CommonJS works with require.
Here is what worked for me:
Turn your js file into .mjs as suggested in other answers
"require" is not defined with the ES6 module, so you can define it this way:
import { createRequire } from 'module'
const require = createRequire(import.meta.url);
Now 'require' can be used in the usual way.
Use import for ES6 modules and require for CommonJS.
Some useful links: Node.js's own documentation. difference between import and require. Mozilla has some nice documentation about import
I had the same issue and the following has fixed it (using Node.js 12.13.1):
Change .js files extension to .mjs
Add --experimental-modules flag upon running your app.
Optional: add "type": "module" in your package.json
More information: https://nodejs.org/api/esm.html
First we'll install #babel/cli, #babel/core and #babel/preset-env:
npm install --save-dev #babel/cli #babel/core #babel/preset-env
Then we'll create a .babelrc file for configuring Babel:
touch .babelrc
This will host any options we might want to configure Babel with:
{
"presets": ["#babel/preset-env"]
}
With recent changes to Babel, you will need to transpile your ES6 before Node.js can run it.
So, we'll add our first script, build, in file package.json.
"scripts": {
"build": "babel index.js -d dist"
}
Then we'll add our start script in file package.json.
"scripts": {
"build": "babel index.js -d dist", // replace index.js with your filename
"start": "npm run build && node dist/index.js"
}
Now let's start our server.
npm start
I Tried with all the methods, but nothing worked.
I got one reference from GitHub.
To use TypeScript imports with Node.js, I installed the below packages.
1. npm i typescript --save-dev
2. npm i ts-node --save-dev
Won't require type: module in package.json
For example,
{
"name": "my-app",
"version": "0.0.1",
"description": "",
"scripts": {
},
"dependencies": {
"knex": "^0.16.3",
"pg": "^7.9.0",
"ts-node": "^8.1.0",
"typescript": "^3.3.4000"
}
}
Step 1
yarn add esm
or
npm i esm --save
Step 2
package.json
"scripts": {
"start": "node -r esm src/index.js",
}
Step 3
nodemon --exec npm start
Node v14.16.0
For those who've tried .mjs and got:
Aviator#AW:/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex$ node just_js.mjs
file:///mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex/just_js.mjs:3
import fetch from "node-fetch";
^^^^^
SyntaxError: Unexpected identifier
and who've tried import fetch from "node-fetch";
and who've tried const fetch = require('node-fetch');
Aviator#AW:/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex$ node just_js.js
(node:4899) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/mnt/c/Users/Adrian/Desktop/Programming/nodejs_ex/just_js.js:3
import fetch from "node-fetch";
^^^^^^
SyntaxError: Cannot use import statement outside a module
and who've tried "type": "module" to package.json, yet continue seeing the error,
{
"name": "test",
"version": "1.0.0",
"description": "to get fetch working",
"main": "just_js.js",
"type": "module",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "MIT"
}
I was able to switch to axios without a problem.
import axios from 'axios'; <-- put at top of file.
Example:
axios.get('https://www.w3schools.com/xml/note.xml').then(resp => {
console.log(resp.data);
});
I found the 2020 update to the answer in this link helpful to answering this question as well as telling you WHY it does this:
Using Node.js require vs. ES6 import/export
Here's an excerpt:
"Update 2020
Since Node v12, support for ES modules is enabled by default, but it's still experimental at the time of writing this. Files including node modules must either end in .mjs or the nearest package.json file must contain "type": "module". The Node documentation has a ton more information, also about interop between CommonJS and ES modules."
I'm new to Node.js, and I got the same issue for the AWS Lambda function (using Node.js) while fixing it.
I found some of the differences between CommonJS and ES6 JavaScript:
ES6:
Add "type":"module" in the package.json file
Use "import" to use from lib.
Example: import jwt_decode from jwt-decode
Lambda handler method code should be define like this
"exports.handler = async (event) => { }"
CommonJS:
Don't add "type":"module" in the package.json file
Use "require" to use from lib.
Example: const jwt_decode = require("jwt-decode");
The lambda handler method code should be defines like this:
"export const handler = async (event) => { }"
In my case. I think the problem is in the standard node executable. node target.ts
I replaced it with nodemon and surprisingly it worked!
The way using the standard executable (runner):
node target.ts
The way using the nodemon executable (runner):
nodemon target.ts
Do not forget to install nodemon with npm install nodemon ;P
Note: this works amazing for development. But, for runtime, you may execute node with the compiled js file!
To use import, do one of the following.
Rename the .js file to .mjs
In package.json file, add {type:module}
If you are using ES6 JavaScript imports:
install cross-env
in package.json change "test": "jest" to "test": "cross-env NODE_OPTIONS=--experimental-vm-modules jest"
more in package.json, add these:
...,
"jest": {
"transform": {}
},
"type": "module"
Explanation:
cross-env allows to change environment variables without changing the npm command. Next, in file package.json you change your npm command to enable experimental ES6 support for Jest, and configure Jest to do it.
This error also comes when you run the command
node filename.ts
and not
node filename.js
Simply put, with the node command we will have to run the JavaScript file (filename.js) and not the TypeScript file unless we are using a package like ts-node.
If you want to use BABEL, I have a simple solution for that!
Remember this is for nodejs example: like an expressJS server!
If you are going to use react or another framework, look in the babel documentation!
First, install (do not install unnecessary things that will only trash your project!)
npm install --save-dev #babel/core #babel/node
Just 2 WAO
then config your babel file in your repo!
file name:
babel.config.json
{
"presets": ["#babel/preset-env"]
}
if you don't want to use the babel file, use:
Run in your console, and script.js is your entry point!
npx babel-node --presets #babel/preset-env -- script.js
the full information is here; https://babeljs.io/docs/en/babel-node
I had this error in my NX workspace after upgrading manually. The following change in each jest.config.js fixed it:
transform: {
'^.+\\.(ts|js|html)$': 'jest-preset-angular',
},
to
transform: {
'^.+\\.(ts|mjs|js|html)$': 'jest-preset-angular',
},
I had this issue when I was running migration
Its es5 vs es6 issue
Here is how I solved it
I run
npm install #babel/register
and add
require("#babel/register")
at the top of my .sequelizerc file my
and go ahead to run my sequelize migrate.
This is applicable to other things apart from sequelize
babel does the transpiling
Just add --presets '#babel/preset-env'.
For example,
babel-node --trace-deprecation --presets '#babel/preset-env' ./yourscript.js
Or
in babel.config.js
module.exports = {
presets: ['#babel/preset-env'],
};
To make your import work and avoid other issues, like modules not working in Node.js, just note that:
With ES6 modules you can not yet import directories. Your import should look like this:
import fs from './../node_modules/file-system/file-system.js'
For people coming to this thread due to this error in Netlify functions even after adding "type": "module" in package.json file, update your netlify.toml to use 'esbuild'. Since esbuild supports ES6, it would work.
[functions]
node_bundler = "esbuild"
Reference:
https://docs.netlify.com/functions/build-with-javascript/#automated-dependency-bundling
The documentation is confusing. I use Node.js to perform some local task in my computer.
Let's suppose my old script was test.js. Within it, if I want to use
import something from "./mylocalECMAmodule";
it will throw an error like this:
(node:16012) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
SyntaxError: Cannot use import statement outside a module
...
This is not a module error, but a Node.js error. Forbid loading anything outside a 'module'.
To fix this, just rename your old script test.js into test.mjs.
That's all.
My solution was to include babel-node path while running nodemon as follows:
nodemon node_modules/.bin/babel-node index.js
You can add in your package.json script as:
debug: nodemon node_modules/.bin/babel-node index.js
NOTE: My entry file is index.js. Replace it with your entry file (many have app.js/server.js).
I had the same problem when I started to use Babel... But later, I
had a solution... I haven't had the problem any more so far...
Currently, Node.js v12.14.1, "#babel/node": "^7.8.4", I use babel-node and nodemon to execute (Node.js is fine as well..)
package.json: "start": "nodemon --exec babel-node server.js "debug": "babel-node debug server.js"!! Note: server.js is my entry
file, and you can use yours.
launch.json. When you debug, you also need to configure your launch.json file "runtimeExecutable":
"${workspaceRoot}/node_modules/.bin/babel-node"!! Note: plus
runtimeExecutable into the configuration.
Of course, with babel-node, you also normally need and edit another file, such as the babel.config.js/.babelrc file
In case you're running nodemon for the Node.js version 12, use this command.
server.js is the "main" inside package.json file, replace it with the relevant file inside your package.json file:
nodemon --experimental-modules server.js
I recently had the issue. The fix which worked for me was to add this to file babel.config.json in the plugins section:
["#babel/plugin-transform-modules-commonjs", {
"allowTopLevelThis": true,
"loose": true,
"lazy": true
}],
I had some imported module with // and the error "cannot use import outside a module".
If you are using node, you should refer to this document. Just setup babel in your node app it will work and It worked for me.
npm install --save-dev #babel/cli #babel/core #babel/preset-env
When I used sequelize migrations with npx sequelize db:migrate, I got this error, so my solution for this was adding the line require('#babel/register'); into the .sequelizerc file as the following image shows:
Be aware you must install Babel and Babel register.
Wrong MIME-Type for JavaScript Module Files
The common source of the problem is the MIME-type for "Module" type JavaScript files is not recognized as a "module" type by the server, the client, or the ECMAScript engine that process or deliver these files.
The problem is the developers of Module JavaScript files incorrectly associated Modules with a new ".mjs" (.js) extension, but then assigned it a MIME-type server type of "text/javascript". This means both .js and .mjs types are the same. In fact the new type for .js JavaScript files has also changed to "application/javascript", further confusing the issue. So Module JavaScript files are not being recognized by any of these systems, regardless of Node.js or Babel file processing systems in development.
The main problem is this new "module" subtype of JavaScript is yet known to most servers or clients (modern HTML5 browsers). In other words, they have no way to know what a Module file type truly is apart from a JavaScript type!
So, you get the response you posted, where the JavaScript engine is saying it needs to know if the file is a Module type of JavaScript file.
The only solution, for server or client, is to change your server or browser to deliver a new Mime-type that trigger ES6 support of Module files, which have an .mjs extension. Right now, the only way to do that is to either create a HTTP content-type on the server of "module" for any file with a .mjs extension and change your file extension on module JavaScript files to ".mjs", or have an HTML script tag with type="module" added to any external <script> element you use that downloads your external .js JavaScript module file.
Once you fool the browser or JavaScript engines into accepting the new Module file type, they will start doing their scripting circus tricks in the JS engines or Node.js systems you use.
I'm trying to export a Vue component as a package, and using vue cli to build the dist. I intend to publish it on npm, but I'm currently using a symbolic link for testing purpose. However even with a simple hello-world project I can't make a valid package.
I created a project:
vue create hello-world
Then I modified the package.json:
"scripts": {
"serve": "vue-cli-service serve",
"build": "vue-cli-service build --target lib --name vue-hello-world ./src/components/HelloWorld.vue",
"lint": "vue-cli-service lint"
},
"main": "./dist/vue-hello-world.common.js",
Then I call
npm run build
and it compiles without error.
Then I make an import in a vue component in another project (I used a symbolic link in node_modules):
import HelloWorld from "hello-world";
On page render I get the following error:
[Vue warn]: Failed to resolve async component: function MediaViewerPdf() {
return Promise.all(/*! import() */[__webpack_require__.e(62), __webpack_require__.e(46)]).then(__webpack_require__.bind(null, /*! ./viewers/MediaViewerPdf.vue */ "./vuejs/components/mediaViewer/viewers/MediaViewerPdf.vue"));
}
Reason: ReferenceError: require is not defined
Any idea what's happening?
Remarks:
using vue inspect, I checked that in webpack config that:
target: "web"
I already set resolve.symlinks at false on the importing project.
EDIT: I have confirmed that it doesn't come from the symbolic link, I have exactly the same error with package directly on node_modules.
Repo with whole code: https://github.com/louis-sanna/vue-hello-world
So I asked the question on the vue-cli repo and I got the solution! https://github.com/vuejs/vue-cli/issues/4245
Turns out NODE_ENV was already set at development in my shell, so it was the mode used to make the build.
Just need to set the mode explicitly and it works:
vue-cli-service build --target lib --name vue-hello-world ./src/components/HelloWorld.vue --mode production
You may need to add it to vue.config.js:
config
.mode("production")
This happens due to the fact that Vue CLI Webpack setup by default does not import commonjs modules, as described in your "main" field in package.json. So the problem is with the project that attempts import, not with the project that exports the component.
There are two ways to attempt to solve this problem.
From the importing project side
You can remedy this by installing babel plugins for the project that imports your components and setting babel.config.js
module.exports = {
presets: [
'#vue/app'
],
plugins: [
'#babel/plugin-transform-modules-commonjs', // leave to import .common.js files
'#babel/plugin-transform-modules-umd' // leave to import .umd.js files
]
}
But doing this alone will not be sufficient: you also will need to import CSS that is generated with the library by adding this in your entry file
import 'hello-world/dist/vue-hello-world.css';
Note that I have only tested this using yarn link, but I have confidence that this will work with an imported separate npm module just fine.
From the library side
The intent (I suppose) of the original question - how do I bundle a library so my users don't have to do this little dance each time they want to use it?
Option 1: don't bundle it - provide .vue files and sources. Just include everything in 'src' directory of your module, write a readme with explanation and be done with it. Let the importing project figure the compilation and bundling out.
Option 2: use rollup with Vue plugin to roll components into bundle. There is an example on how to do that. In that example you can see that your project will be able to import .esm build
https://github.com/vuejs/rollup-plugin-vue/tree/master/cookbook/library
Not sure how you are creating the symbolic link, but you should use npm link for that. If you are still having problems (like I did myself) I would suggest you try npm-link-better:
npm install -g npm-link-better
cd vue-hello-world
npm link
cd ../hello-world
nlc -w vue-hello-world
For building component libraries, I suggest you have a look at vue-cli-plugin-component. This plugin already sets up the vue-cli project pretty well.
I want to create a plugin so that I can raw-load a certain type of file with parcel. Parcel docs states that:
Publish this package on npm using parcel-plugin- or #your-scope/parcel-plugin- prefixes, and it will be automatically detected and loaded as described below.
...
Any dependencies listed in package.json with these prefixes will automatically be loaded during initialization.
Since this is a one-time thing, I don't want to publish the code on npm as a plugin. How do I load my project-local plugin with parcel?
Thanks in advance.
Since I could not find a way to do this in a parcel way, I did this in an npm way:
I created a folder named local_modules (this can be anything you want.) Then created parcel-plugin-x inside local_modules. Inside that, I created my plugin as usual. I also created a package.json specifying the entry point main. You can specify the dependencies required for the module just like if this is a separate project (THIS IS!).
{
"name": "parcel-plugin-x",
"version": "0.1.0",
"description": "Parcel plugin x",
"main": "index.js",
"devDependencies": {
},
"dependencies": {
}
}
Directory structure:
project-folder---local_modules---parcel-plugin-x
|---package.json |
|---index.js
|---package.json
Then I ran npm i --save-dev .local_modules/parcel-plugin-x inside the project-folder. It adds the line "parcel-plugin-x": "./local_modules/parcel-plugin-x", to the root package.json. This is the standard way of loading local modules in npm. And everytime you make changes to the plugin, you have to run npm upgrade. You should also increase the version of your plugin, too. This copies the plugin to node_modules and install dependancies.
According to the parceljs docs:
Any dependencies listed in package.json with these prefixes will
automatically be loaded during initialization.
now it works! :)
I did something similar, but with npm link.
In plugin folder (parcel-plugin-x) just run: npm link.
In the project folder using the plugin:
Link to parcel-plugin-x: npm link parcel-plugin-x
In package.json file, manually add the dependency to parcel-plugin-x
package.json
"devDependencies": {
"parcel-plugin-x": "^0"
}
Each time you make changes to the plugin, you don't have to run npm upgrade, but you might have to remove .cache folder created by parcel, because parcel will skip processing cached assets.
I think you can do this with the workspaces option in package.json: https://docs.npmjs.com/cli/v7/using-npm/workspaces
This library seems to be implementing it: https://github.com/astegmaier/stackoverflow-parcel-namer