Невозможно использовать инструкцию import вне модуля

The Uncaught SyntaxError: cannot use import statement outside a module mainly occurs when developers use the import statement on the CommonJS instead of require statement.

What is SyntaxError: cannot use import statement outside a module?

There are several reasons behind this error. First, let us look at each scenario and solution with examples.

• If you are using an older Node version < 13
• If you are using a browser or interface that doesn’t support ES6
• If you have missed the type=”module” while loading the script tag
• If you missed out on the “type”: “module” inside the package.json while working on Node projects

Many interfaces till now do not understand ES6 Javascript features. Hence we need to compile ES6 to ES5 whenever we need to use that in the project.

The other possible reason is that you are using the file that is written in the ES6 module directly inside your code. It means you are loading the src file/directory instead of referring to the dist directory, which leads to a SyntaxError.

Usually, we use a bundled or dist file that is compiled to ES5/Javascript file and then import the modules in our code.

How to fix SyntaxError: cannot use import statement outside a module?

There are 3 ways to solve this error. Let us take a look at each of these solutions.

Solution 1 – Add “type”: “module” to package.json 

If you are working on Node.js or react applications and using import statements instead of require to load the modules, then ensure your package.json has a property "type": "module" as shown below.

Adding “type”: “module” to package.json will tell Node you are using ES6 modules(es modules), which should get solve the error. 

If you would like to use the ES6 module imports in Node.js, set the type property to the module in the package.json file.

   {
        // ...
        "type": "module",
        // ...
    }

If you are using TypeScript, we need to edit the tsconfig.json file and change the module property to “commonjs“, as shown below.

ts.config file

Change the ts.config file as shown below to resolve the Uncaught SyntaxError: cannot use import statement outside a module error.

    "target": "esnext",
    "module": "esnext",

to

    "target": "esnext",
    "module": "commonjs",

If this error mainly occurs in the TypeScript project, ensure that you are using a ts-node to transpile into Javascript before running the .ts file. Node.js can throw an error if you directly run the typescript file without transpiling.

Note: If your project does not have a package.json file, initialize it by using the npm init -y command in the root directory of your project.

Solution 2 – Add type=”module” attribute to the script tag

Another reason we get this error is if we are loading the script from the src directory instead of the built file inside the dist directory. 

It can happen if the src file is written in ES6 and not compiled into an ES5 (standard js file). The dist files usually will have the bundled and compiled files, and hence it is recommended to use the dist folder instead of src.

We can solve this error by adding a simple attribute type="module" to the script, as shown below.

<script type="module" src="some_script.js"></script>

Solution 3 – Use import and require to load the modules

In some cases, we may have to use both import and require statements to load the module properly.

For Example – 

    import { parse } from 'node-html-parser';
    parse = require('node-html-parser');

Note: When using modules, if you get ReferenceError: require is not defined, you’ll need to use the import syntax instead of require.

Configuration Issue in ORM’s

Another possible issue is when you are using ORM’s such as typeORM and the configuration you have set the entities to refer to the source folder instead of the dist folder.

The src folder would be of TypeScript file and referring the entities to .ts files will lead to cannot use import statement outside a module error.

Change the ormconfig.js to refer to dist files instead of src files as shown below.

 "entities": [
      "src/db/entity/**/*.ts", // Pay attention to "src" and "ts" (this is wrong)
   ],

to

  "entities": [
      "dist/db/entity/**/*.js", // Pay attention to "dist" and "js" (this is the correct way)
   ],

Conclusion

The Uncaught SyntaxError: cannot use import statement outside a module occurs if you have forgotten to add type="module" attribute while loading the script or if you are loading the src files instead of bundled files from the dist folder.

We can resolve the issue by setting the “type”: “module” inside the package.json while working on Node projects. If we are loading the Javascript file then we need to add the attribute type="module" to the script tag.