Webpack cant resolve TypeScript modules
JavascriptTypescriptWebpackTs LoaderJavascript Problem Overview
I build a relay small webpack and typescript demo to play with. If i run webpack with the webpack.config.js i get this error:
ERROR in ./js/app.ts
Module not found: Error: Can't resolve './MyModule' in '/Users/timo/Documents/Dev/Web/02_Tests/webpack_test/js'
@ ./js/app.ts 3:17-38
I have no clue what the problem could be. The module export should be correct.
webpack.config.js
const path = require('path');
module.exports = {
entry: './js/app.ts',
output: {
path: path.resolve(__dirname, 'dist'),
filename: 'bundle.js'
},
module: {
rules: [
{test: /\.ts$/, use: 'ts-loader'}
]
}
};
tsconfig.json
{
"compilerOptions": {
"target": "es5",
"suppressImplicitAnyIndexErrors": true,
"strictNullChecks": false,
"lib": [
"es5", "es2015.core", "dom"
],
"module": "commonjs",
"moduleResolution": "node",
"outDir": "dist"
},
"include": [
"js/**/*"
]
}
src/app.js
import { MyModule } from './MyModule';
let mym = new MyModule();
console.log('Demo');
mym.createTool();
console.log(mym.demoTool(3,4));
src/MyModule.ts
export class MyModule {
createTool() {
console.log("Test 123");
}
demoTool(x:number ,y:number) {
return x+y;
}
};
src/index.html
<html>
<head>
<title>Demo</title>
<base href="/">
</head>
<body>
<script src="dist/bundle.js"></script>
</body>
</html>
Javascript Solutions
Solution 1 - Javascript
Webpack does not look for .ts files by default. You can configure resolve.extensions to look for .ts. Don't forget to add the default values as well, otherwise most modules will break because they rely on the fact that the .js extension is automatically used.
resolve: {
extensions: ['.ts', '.js', '.json']
}
Solution 2 - Javascript
Tried all the suggestions above and it still didn't work.
Ended up being the tiniest detail:
In webpack.js, instead of:
resolve: {
extensions: ['.tsx', '.ts', '.js']
},
The ordering should be:
resolve: {
extensions: ['.ts', '.tsx', '.js']
},
Don't know why this is necessary, and to be quite honest, I'm beyond caring at this point...
Solution 3 - Javascript
Leaving this here for posterity, but I had this exact same issue and my problem was that my entry path was not relative but absolute. I changed entry from:
entry: 'entry.ts'
to
entry: './entry.ts'
Solution 4 - Javascript
I'm a bit late to the party, but is better to use:
resolve: {
extensions: ['.jsx', '.ts', '.tsx', '...']
}
... means that we'll not overwrite the default, only add to it
Solution 5 - Javascript
I'm using tsconfig instead of webpack which also compiles the submodule to a bundle (index.js).
The issue for me was that I had forgotten to compile the submodule (ie run tsc to generate index.js) before referencing it from outside.