Configure typescript to output imports with extensions, ex: `from './file.js`` - node.js

Using node 14.x I would like to switch my project to full ES Modules, as it's now supported.
So I enabled on package.json "type": "module"
and my tsconfig.json looks like that:
{
"compilerOptions": {
"outDir": "dist", /* Redirect output structure to the directory. */
"strict": true, /* Enable all strict type-checking options. */
"esModuleInterop": true, /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
"skipLibCheck": true, /* Skip type checking of declaration files. */
"forceConsistentCasingInFileNames": true, /* Disallow inconsistently-cased references to the same file. */
"allowSyntheticDefaultImports": true,
"lib": ["ES2020"],
"module": "ESNext",
"moduleResolution": "node",
"target": "ES2020"
}
}
But the output files have unspecified extension in imports, it's instead REQUIRED for node 14.x to specify full file ext
For example:
import { ENV, redisConfig } from './config';
should instead be:
import { ENV, redisConfig } from './config.js';

TS won't handle that for you, but you can run Node with the node --experimental-specifier-resolution=node parameter.
Source
Unfortunately it seems that TS isn't going to support adding extension to the end of the import, since apparently it's not as simple as adding .js to the end of the import.

Related

Why am I getting "parserOptions.project" has been set for #typescript-eslint/parser specifically for .test.ts files?

I have been trying to fix this error for .test.ts files for the past three days.
I have my tsconfig as follows
{
"compilerOptions": {
"target": "es6", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
"lib": ["ESNext"], /* Specify a set of bundled library declaration files that describe the target runtime environment. */
"module": "commonjs", /* Specify what module code is generated. */
"rootDir": "./src", /* Specify the root folder within your source files. */
"moduleResolution": "node", /* Specify how TypeScript looks up a file from a given module specifier. */
"baseUrl": "src", /* Specify the base directory to resolve non-relative module names. */
"types": ["jest", "node"], /* Specify type package names to be included without being referenced in a source file. */
"resolveJsonModule": true, /* Enable importing .json files */
"allowJs": true, /* Allow JavaScript files to be a part of your program. Use the `checkJS` option to get errors from these files. */
"checkJs": true, /* Enable error reporting in type-checked JavaScript files. */
"outDir": "./dist", /* Specify an output folder for all emitted files. */
"removeComments": true, /* Disable emitting comments. */
"importsNotUsedAsValues": "error", /* Specify emit/checking behavior for imports that are only used for types */
"isolatedModules": true, /* Ensure that each file can be safely transpiled without relying on other imports. */
"allowSyntheticDefaultImports": true, /* Allow 'import x from y' when a module doesn't have a default export. */
"esModuleInterop": true, /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables `allowSyntheticDefaultImports` for type compatibility. */
// "preserveSymlinks": true, /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
"forceConsistentCasingInFileNames": true, /* Ensure that casing is correct in imports. */
/* Type Checking */
"strict": true, /* Enable all strict type-checking options. */
"noImplicitAny": true, /* Enable error reporting for expressions and declarations with an implied `any` type.. */
"noUnusedLocals": true, /* Enable error reporting when a local variables aren't read. */
"noUnusedParameters": true, /* Raise an error when a function parameter isn't read */
"exactOptionalPropertyTypes": false, /* Interpret optional property types as written, rather than adding 'undefined'. */
"noImplicitReturns": true, /* Enable error reporting for codepaths that do not explicitly return in a function. */
"noFallthroughCasesInSwitch": true, /* Enable error reporting for fallthrough cases in switch statements. */
"noUncheckedIndexedAccess": true, /* Include 'undefined' in index signature results */
"noImplicitOverride": true, /* Ensure overriding members in derived classes are marked with an override modifier. */
"noPropertyAccessFromIndexSignature": true, /* Enforces using indexed accessors for keys declared using an indexed type */
"allowUnusedLabels": false, /* Disable error reporting for unused labels. */
"allowUnreachableCode": false, /* Disable error reporting for unreachable code. */
"skipLibCheck": true /* Skip type checking all .d.ts files. */
},
"include": ["src"],
"exclude": ["node_modules", "dist", "coverage", "src/__tests__", "**/*.test.ts"]
}
And my eslintrc.js has these contents
module.exports = {
env: {
es2021: true,
node: true,
jest: true,
},
extends: [
'eslint:recommended',
'airbnb-base',
'plugin:#typescript-eslint/recommended',
'plugin:#typescript-eslint/recommended-requiring-type-checking',
'plugin:prettier/recommended',
'plugin:import/typescript',
'prettier'
],
parser: '#typescript-eslint/parser',
parserOptions: {
sourceType: 'module',
project: 'tsconfig.json',
tsconfigRootDir: './',
},
plugins: ['#typescript-eslint', 'prettier', 'import'],
rules: {
}
}
In src/__tests__/sample.test.ts I get this error
Parsing error: "parserOptions.project" has been set for #typescript-eslint/parser.
The file does not match your project config: src/__tests__/sample.test.ts.
The file must be included in at least one of the projects provided.
I have noticed that it only occurs for .test.ts files rest of the typescript files with only .ts extension are working fine
What am I missing?
So, since I was excluding the test files in tsconfig,json I had to somehow add those files for eslint to lint during development and also exclude them on build time.
I ended up creating a new file tsconfig.eslint.json with the contents
{
"extends": "./tsconfig.json", <-- since the entire src folder is already included here
"exclude": ["node_modules", "dist", "coverage"] <--- override the exclude property to not have test files here
}
And in my eslintrc.js
parserOptions: {
sourceType: 'module',
project: 'tsconfig.eslint.json',
tsconfigRootDir: './',
},
This fixes the error.

Typescript declaration file for an external npm package - constructor

I am using ES6 and Typescript for my Node project, however one library is a commonjs library.
For that library, I created my own .d.ts declaration file:
module "#alpacahq/alpaca-trade-api" {
export interface AlpacaParams { ... }
// ...
export class Alpaca implements Broker {
// ...
constructor(params: AlpacaParams);
}
export default Alpaca;
}
Everything works as expected, but I'm having a problem with the constructor.
If I use that class from within my project, and I try this:
this.alpaca = new Alpaca.Alpaca({...});
I get told that Alpaca.Alpaca is not a constructor.
The only way it seems to work is if I do:
this.alpaca = new Alpaca.default({...});
I'm quite new to Typescript, so I'm sure I'm doing something wrong. Any ideas?
The latter works, so I'm not blocked in my work, but I would like to set things up properly.
Thank you!
Edited to show TS config and imports
tsconfig.json
{
"compilerOptions": {
"target": "es6",
"module": "es6",
"lib": ["es6", "es5"],
"sourceMap": true,
"outDir": "dist",
"rootDir": "src",
"strict": true,
"moduleResolution": "node",
"typeRoots": ["./types"],
"esModuleInterop": true,
"resolveJsonModule": true,
"skipLibCheck": true,
"forceConsistentCasingInFileNames": true
}
}
This is how I import it. Couldn't figure out how to make it work otherwise. If I import modules ES6 style, it breaks unless I use commonjs. If I use commonjs, I get an "export undefined" error.
import * as Alpaca from '#alpacahq/alpaca-trade-api';
The problem is that you're importing all named exports with import * meaning that Alpaca refers to the module and .default refers to the exported class. Instead you should be importing just the default member.
Change your import to look like this:
// Import default member from module
import Alpaca from '#alpacahq/alpaca-trade-api';
this.alpaca = new Alpaca({...});

Can't run my Node.js Typescript project TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for /app/src/App.ts

When I try to start my app on Heroku I got the following stack trace.
It is just a basic ts.app like you see with ts-node and nodemon.
I am really interested in what the answer is going to be.
2020-05-30T00:03:12.201106+00:00 heroku[web.1]: Starting process with command `npm start`
2020-05-30T00:03:14.405285+00:00 app[web.1]:
2020-05-30T00:03:14.405303+00:00 app[web.1]: > discordtoornamentmanager#1.0.0 start /app
2020-05-30T00:03:14.405303+00:00 app[web.1]: > ts-node src/App.ts
2020-05-30T00:03:14.405304+00:00 app[web.1]:
2020-05-30T00:03:14.833655+00:00 app[web.1]: (node:23) ExperimentalWarning: The ESM module loader is experimental.
2020-05-30T00:03:14.839311+00:00 app[web.1]: TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for /app/src/App.ts
2020-05-30T00:03:14.839312+00:00 app[web.1]: at Loader.defaultGetFormat [as _getFormat] (internal/modules/esm/get_format.js:65:15)
2020-05-30T00:03:14.839314+00:00 app[web.1]: at Loader.getFormat (internal/modules/esm/loader.js:113:42)
2020-05-30T00:03:14.839315+00:00 app[web.1]: at Loader.getModuleJob (internal/modules/esm/loader.js:244:31)
2020-05-30T00:03:14.839315+00:00 app[web.1]: at processTicksAndRejections (internal/process/task_queues.js:97:5)
2020-05-30T00:03:14.839316+00:00 app[web.1]: at Loader.import (internal/modules/esm/loader.js:178:17)
2020-05-30T00:03:14.847801+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2020-05-30T00:03:14.847998+00:00 app[web.1]: npm ERR! errno 1
2020-05-30T00:03:14.848957+00:00 app[web.1]: npm ERR! discordtoornamentmanager#1.0.0 start: `ts-node src/App.ts`
2020-05-30T00:03:14.849050+00:00 app[web.1]: npm ERR! Exit status 1
2020-05-30T00:03:14.849172+00:00 app[web.1]: npm ERR!
2020-05-30T00:03:14.849254+00:00 app[web.1]: npm ERR! Failed at the discordtoornamentmanager#1.0.0 start script.
2020-05-30T00:03:14.849337+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2020-05-30T00:03:14.854859+00:00 app[web.1]:
2020-05-30T00:03:14.854998+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2020-05-30T00:03:14.855069+00:00 app[web.1]: npm ERR! /app/.npm/_logs/2020-05-30T00_03_14_850Z-debug.log
2020-05-30T00:03:14.907689+00:00 heroku[web.1]: Process exited with status 1
2020-05-30T00:03:14.943718+00:00 heroku[web.1]: State changed from starting to crashed
This is my package.json
{
"name": "discordtoornamentmanager",
"version": "1.0.0",
"description": "",
"main": "dist/app.js",
"type": "module",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"dev": "nodemon -x ts-node src/App.ts",
"start": "ts-node src/App.ts"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"#types/node": "^14.0.5",
"axios": "^0.19.2",
"discord.js": "^12.2.0",
"pg": "^8.2.1",
"reflect-metadata": "^0.1.10",
"typeorm": "0.2.25",
"typescript": "^3.9.3",
"nodemon": "^2.0.4",
"ts-node": "8.10.1"
}
}
And this is my tsconfig
{
"compilerOptions": {
"lib": [
"es6"
],
"target": "es6",
"module": "commonjs",
"moduleResolution": "node",
"outDir": "dist",
"resolveJsonModule": true,
"emitDecoratorMetadata": true,
"esModuleInterop": true,
"experimentalDecorators": true,
"sourceMap": true
},
"include": ["src/**/*.ts"],
"exclude": ["node_modules", "**/*.spec.ts"]
}
Remove "type": "module" from package.json
https://github.com/TypeStrong/ts-node/issues/935
https://github.com/TypeStrong/ts-node/issues/1007#issuecomment-1163471306
If you don't want to remove "type": "module" (for example if you're using import statements in your .ts which allows the inference of types from modules), then you can use the following option in tsconfig.json:
{
"compilerOptions": {
"esModuleInterop": true,
}
}
And then you can start the server with the config using ts-node.
Install:
npm install -g ts-node
Run:
ts-node-esm my_server.ts
use
node --loader ts-node/esm ./my-script.ts
instead of
ts-node ./my-script.ts
MARCH 2022
USING: Node 16.6.2, ts-node v 10.7.0
What worked for me was having "type": "module" in package.json, and adding
node --experimental-specifier-resolution=node --loader ts-node/esm ./src/app.ts
tsconfig.json:
{
"compilerOptions": {
"module": "ESNext",
"esModuleInterop": true,
"target": "ESNext",
"moduleResolution": "Node",
"outDir": "dist",
"forceConsistentCasingInFileNames": true,
"noFallthroughCasesInSwitch": true,
"isolatedModules": false,
"strict": true,
"noImplicitAny": true,
"useUnknownInCatchVariables": false,
"inlineSourceMap": true
},
"ts-node": {
"esm": true
},
"lib": ["esnext"]
}
Credits to #FelipePlets for the useful answer here
EDIT
You may want to use a non-esnext option, as per the ts docs:
The special ESNext value refers to the highest version your version of TypeScript supports. This setting should be used with caution, since it doesn’t mean the same thing between different TypeScript versions and can make upgrades less predictable.
Removing "type": "module" from package.json and adding:
"compilerOptions": {
"module": "CommonJS"
},
In tsconfig.json fixed this for me.
Solution One
Remove "type": "module" from package.json if it's added
In tsconfig.json under the compilerOptions Set module property to CommonJS module: "CommonJS" and moduleResolution: "Node"
Solution Two
if the first one didn't work, or you have for some reason to keep module: "ESNext"
1- Add "type": "module" to package.json
2- Install ts-node npm i -g ts-node
3- Go to tsconfig.json and add the following:
{
"compilerOptions": {
"module": "ESNext",
"moduleResolution": "Node",
/* ... your props ... */
},
"ts-node": {
"esm": true
}
}
4- Run ts-node fileName.ts
Try adding this to your tsconfig.json
"ts-node": {
"esm": true,
"experimentalSpecifierResolution": "node",
}
I was able to fix with a tsconfig.json that looked something like:
{
"compilerOptions": {
"target": "es2022",
"lib": ["ES2022"],
"allowJs": true,
"skipLibCheck": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"strict": true,
"forceConsistentCasingInFileNames": true,
"noFallthroughCasesInSwitch": true,
"module": "ES2022",
"moduleResolution": "node",
"resolveJsonModule": true,
"isolatedModules": true,
"noEmit": true,
},
"exclude": [
"node_modules",
],
"ts-node": {
"esm": true,
"experimentalSpecifierResolution": "node",
}
}
I first came across this problem probably over a year ago, and ts-node has yet to fix it. None of the above solutions worked for me, and I have seemingly tried everything.
I just resorted to using tsc --outDir out file.ts and then running the file normally with node out/file.js, and then adding out to the .gitignore.
The thought behind ts-node is wonderful, just really sucks when it can't handle seemingly straightforward examples like this. Apologies the solution doesn't use ts-node, but I couldn't get it to work.
I made some changes on my package.json & tsconfig.json.Finally, it worked for me!
Add "type": "module" to package.json
Uncomment "moduleResolution": "node" section in your tsconfig.json
Change "module" section to "ESNEXT" in your tsconfig.json
Then Just Run the main script with this node --loader ts-node/esm .\index.ts
tsconfig.json
{
"compilerOptions": {
/* Visit https://aka.ms/tsconfig.json to read more about this file */
/* Projects */
// "incremental": true, /* Enable incremental compilation */
// "composite": true, /* Enable constraints that allow a TypeScript project to be used with project references. */
// "tsBuildInfoFile": "./", /* Specify the folder for .tsbuildinfo incremental compilation files. */
// "disableSourceOfProjectReferenceRedirect": true, /* Disable preferring source files instead of declaration files when referencing composite projects */
// "disableSolutionSearching": true, /* Opt a project out of multi-project reference checking when editing. */
// "disableReferencedProjectLoad": true, /* Reduce the number of projects loaded automatically by TypeScript. */
/* Language and Environment */
"target": "es5", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
// "lib": [], /* Specify a set of bundled library declaration files that describe the target runtime environment. */
// "jsx": "preserve", /* Specify what JSX code is generated. */
// "experimentalDecorators": true, /* Enable experimental support for TC39 stage 2 draft decorators. */
// "emitDecoratorMetadata": true, /* Emit design-type metadata for decorated declarations in source files. */
// "jsxFactory": "", /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h' */
// "jsxFragmentFactory": "", /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
// "jsxImportSource": "", /* Specify module specifier used to import the JSX factory functions when using `jsx: react-jsx*`.` */
// "reactNamespace": "", /* Specify the object invoked for `createElement`. This only applies when targeting `react` JSX emit. */
// "noLib": true, /* Disable including any library files, including the default lib.d.ts. */
// "useDefineForClassFields": true, /* Emit ECMAScript-standard-compliant class fields. */
/* Modules */
"module": "ESNEXT", // ****HERE /* Specify what module code is generated. */
// "rootDir": "./", /* Specify the root folder within your source files. */
"moduleResolution": "node", // ****HERE /* Specify how TypeScript looks up a file from a given module specifier. */
// "baseUrl": "./", /* Specify the base directory to resolve non-relative module names. */
// "paths": {}, /* Specify a set of entries that re-map imports to additional lookup locations. */
// "rootDirs": [], /* Allow multiple folders to be treated as one when resolving modules. */
// "typeRoots": [], /* Specify multiple folders that act like `./node_modules/#types`. */
// "types": [], /* Specify type package names to be included without being referenced in a source file. */
// "allowUmdGlobalAccess": true, /* Allow accessing UMD globals from modules. */
// "resolveJsonModule": true, /* Enable importing .json files */
// "noResolve": true, /* Disallow `import`s, `require`s or `<reference>`s from expanding the number of files TypeScript should add to a project. */
/* JavaScript Support */
// "allowJs": true, /* Allow JavaScript files to be a part of your program. Use the `checkJS` option to get errors from these files. */
// "checkJs": true, /* Enable error reporting in type-checked JavaScript files. */
// "maxNodeModuleJsDepth": 1, /* Specify the maximum folder depth used for checking JavaScript files from `node_modules`. Only applicable with `allowJs`. */
/* Emit */
// "declaration": true, /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
// "declarationMap": true, /* Create sourcemaps for d.ts files. */
// "emitDeclarationOnly": true, /* Only output d.ts files and not JavaScript files. */
// "sourceMap": true, /* Create source map files for emitted JavaScript files. */
// "outFile": "./", /* Specify a file that bundles all outputs into one JavaScript file. If `declaration` is true, also designates a file that bundles all .d.ts output. */
// "outDir": "./", /* Specify an output folder for all emitted files. */
// "removeComments": true, /* Disable emitting comments. */
// "noEmit": true, /* Disable emitting files from a compilation. */
// "importHelpers": true, /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
// "importsNotUsedAsValues": "remove", /* Specify emit/checking behavior for imports that are only used for types */
// "downlevelIteration": true, /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
// "sourceRoot": "", /* Specify the root path for debuggers to find the reference source code. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Include sourcemap files inside the emitted JavaScript. */
// "inlineSources": true, /* Include source code in the sourcemaps inside the emitted JavaScript. */
// "emitBOM": true, /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
// "newLine": "crlf", /* Set the newline character for emitting files. */
// "stripInternal": true, /* Disable emitting declarations that have `#internal` in their JSDoc comments. */
// "noEmitHelpers": true, /* Disable generating custom helper functions like `__extends` in compiled output. */
// "noEmitOnError": true, /* Disable emitting files if any type checking errors are reported. */
// "preserveConstEnums": true, /* Disable erasing `const enum` declarations in generated code. */
// "declarationDir": "./", /* Specify the output directory for generated declaration files. */
/* Interop Constraints */
// "isolatedModules": true, /* Ensure that each file can be safely transpiled without relying on other imports. */
// "allowSyntheticDefaultImports": true, /* Allow 'import x from y' when a module doesn't have a default export. */
"esModuleInterop": true, /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables `allowSyntheticDefaultImports` for type compatibility. */
// "preserveSymlinks": true, /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
"forceConsistentCasingInFileNames": true, /* Ensure that casing is correct in imports. */
/* Type Checking */
"strict": true, /* Enable all strict type-checking options. */
// "noImplicitAny": true, /* Enable error reporting for expressions and declarations with an implied `any` type.. */
// "strictNullChecks": true, /* When type checking, take into account `null` and `undefined`. */
// "strictFunctionTypes": true, /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
// "strictBindCallApply": true, /* Check that the arguments for `bind`, `call`, and `apply` methods match the original function. */
// "strictPropertyInitialization": true, /* Check for class properties that are declared but not set in the constructor. */
// "noImplicitThis": true, /* Enable error reporting when `this` is given the type `any`. */
// "useUnknownInCatchVariables": true, /* Type catch clause variables as 'unknown' instead of 'any'. */
// "alwaysStrict": true, /* Ensure 'use strict' is always emitted. */
// "noUnusedLocals": true, /* Enable error reporting when a local variables aren't read. */
// "noUnusedParameters": true, /* Raise an error when a function parameter isn't read */
// "exactOptionalPropertyTypes": true, /* Interpret optional property types as written, rather than adding 'undefined'. */
// "noImplicitReturns": true, /* Enable error reporting for codepaths that do not explicitly return in a function. */
// "noFallthroughCasesInSwitch": true, /* Enable error reporting for fallthrough cases in switch statements. */
// "noUncheckedIndexedAccess": true, /* Include 'undefined' in index signature results */
// "noImplicitOverride": true, /* Ensure overriding members in derived classes are marked with an override modifier. */
// "noPropertyAccessFromIndexSignature": true, /* Enforces using indexed accessors for keys declared using an indexed type */
// "allowUnusedLabels": true, /* Disable error reporting for unused labels. */
// "allowUnreachableCode": true, /* Disable error reporting for unreachable code. */
/* Completeness */
// "skipDefaultLibCheck": true, /* Skip type checking .d.ts files that are included with TypeScript. */
"skipLibCheck": true /* Skip type checking all .d.ts files. */
}}
package.json
{
"name": "async-with-ts",
"version": "1.0.0",
"main": "index.js",
"license": "MIT",
"type": "module", // ****HERE
"devDependencies": {
"#types/node-fetch": "^3.0.3",
"ts-node": "^10.2.1",
"typescript": "^4.4.2"
},
"dependencies": {
"node-fetch": "^3.0.0"
}
}
You should be aware of using this command
node --loader ts-node/esm .\index.ts
You can use ts-node-esm instead of ts-node, keeping "type":"module" in package.json, and using import './module.js' in your .ts files.
Related: https://github.com/TypeStrong/ts-node/issues/1007
UPDATE:
This answer has an even better solution as allows to import modules without .js extension:
https://stackoverflow.com/a/65163089/1482990
I tried to remove this error by following methods but FAILED :
1- Using .mts extension
2- Using type:commonjs instead of type:module in package.json (this will not let you use 'import' in your TS file, However i wanted that, therefore i consider this try to be failed).
3- Restarting the VS-Code
Then I tried the following and succeeded :
1- Using --esm flag with ts-node command. e.g => npx ts-node --esm ./src/index.ts
2 - Inside tsConfig.json, add another option after Compiler options' closing bracket named "ts-node" and set its "esm" option to "true", same as below :
{
"compilerOptions": {
"module": "ESNext",
"moduleResolution": "Node",
/* ... your props ... */
},
"ts-node": {
"esm": true
}
}
I followed advice given herein. I also had to uninstall lodash-es and install lodash instead to make it work.
After some experimentation with my ts-node/puppeteer configuration I came up with this:
package.json
{
"type": "module",
"scripts": {
"start": "npx ts-node main.ts"
},
...
}
tsconfig.json
{
"ts-node": { "esm": true, "experimentalSpecifierResolution": "node" },
"compilerOptions": {
"esModuleInterop": true,
"moduleResolution": "node",
"module": "ESNext",
...
},
...
}
Works great for running puppeteer in a TypeScript environment.
(Running NodeJS 19.0.0 with TypeScript 4.9.4 and ts-node 10.9.1)
if your tsconfig.json contains "module": "ESNext". I have used the below script in my package.json. It worked.
"start": "nodemon -e ts -w ./src -x npm run watch:serve",
"watch:serve": "node --loader ts-node/esm src/server.ts",
Running ts-node with --esm worked for me.
For example:
ts-node --esm src/App.ts
That error is caused by trying to import modules, which without the ES Modules flag, ts-node doesn't support.
Update:
Thanks to some maintainers, a working solution is now officially documented by webpack. Just take a small look at the official webpack documentation.
The second solution is similar to other answers here and works perfectly fine in my case.
For me (node version 14), for some reason, the problem was that I install the serialize-error package and when I tried to import it to threw that error.
To solve it I downgraded the version of the package from 11.0.0 to 8.0.0.
If you use PowerShell on VS Code on Windows 11 try to use this command:
ts-node-esm.cmd .\my_script.ts
after this solution: https://stackoverflow.com/a/62099904/8967481
For anyone who is running into this issue while trying run an script in an NX project.
# For apps
ts-node --project tsconfig.app.json $yourFilePath
# For libraries
ts-node --project tsconfig.lib.json $yourFilePath
# For tests
ts-node --project tsconfig.spec.json $yourFilePath
#vadimk7 wasn't far off, my solution was to change my file extension to .mts and then use ts-node-esm myfile.mts
Add this to tsconfig.json
{
/* ... your props ... */
"ts-node": {
"compilerOptions": {
"module": "CommonJS"
}
}
}
July 2022, with the use of ts-node
Node 16.14.2, ts-node 10.8.2
First install ts-node and base configuration
npm install ts-node --save-dev
npm install #tsconfig/node16 --save-dev
tsconfig.json:
{
"extends": "#tsconfig/node16/tsconfig.json",
"compilerOptions": {
"resolveJsonModule": true
},
"include": [
"main.ts"
// here you can include another directories with sources
],
"exclude": [
"node_modules"
]
}
You can remove everything related to modules/compilation from package.json.
And then you can run your program as
ts-node ./main.ts
I wanted to use ES modules instead of commonjs in my project. In addition to making some changes covered in other answers, the last need step for me was to add this to my compilerOptions in tsconfig.json:
"sourceMap": true,
before this:
node --loader ts-node/esm ./my-script.ts
I had to update ssri
npm update ssri --depth 5
Not sure if this will help anyone but I fixed it by putting this at the start:
#!/usr/bin/env node
changing my
"moduleResolution": "node",
to
"moduleResolution": "Node",
in package.json solved this for me
In your package.json {Module:commonJS}, and tsconfig.json {module:commonJS},to ts-node youname.ts
I changed my imports from:
import blah from './modules/blah'
to
import blah from './modules.blah.js'

TypeScript won't import index.js when index.d.ts is present

I'm having strange behavior in TypeScript right now. In a folder separate from my source folder I have generated JS (protobufjs) with type definitions. When I try to import the index file from that folder I get the error [foldername]/index.d.ts is not a module. This even happens if I explicitly import [folder]/index or even [folder]/index.js.
Any idea what could be causing this?
tsconfig looks like this:
{
"compilerOptions": {
"target": "es2017", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
"module": "commonjs",
"declaration": true, /* Generates corresponding '.d.ts' file. */
"declarationMap": true, /* Generates a sourcemap for each corresponding '.d.ts' file. */
"sourceMap": true, /* Generates corresponding '.map' file. */
"outDir": "./dist", /* Redirect output structure to the directory. */
"rootDir": "./src", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
"composite": true, /* Enable project compilation */information */
"removeComments": true, /* Do not emit comments to output. */
"strict": true, /* Enable all strict type-checking options. */
"noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */
"strictNullChecks": true, /* Enable strict null checks. */
"strictFunctionTypes": true, /* Enable strict checking of function types. */
"strictBindCallApply": true, /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
"strictPropertyInitialization": true, /* Enable strict checking of property initialization in classes. */
"noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */
"alwaysStrict": true, /* Parse in strict mode and emit "use strict" for each source file. */
"noUnusedLocals": true, /* Report errors on unused locals. */
"noUnusedParameters": true, /* Report errors on unused parameters. */
"noImplicitReturns": true, /* Report error when not all code paths in function return a value. */
"noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */
"esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
},
"include": [ "src" ],
"exclude": [ "test" ]
}
And possibly of note, the generated file I'm importing is under proto, in the same parent folder as src, and imported via e.g. import * as protos from "../../proto";.
I'm also fairly certain this worked until recently, so some configuration might have changed or a module version updated that I haven't caught as this is a team project. Node 13.9.0, TypeScript 3.7.2.
I just tested this... this is my folder structure
_[project root]
|_test
|_test.js
|_index.d.ts
|_index.ts
|_tsconfig.json
|_package.json
|_package.lock.json
The trick was adding the path to [project root]/test/index.d.ts to my tsconfig.json file.. After that, I no longer got the error about "not a module".. I am assuming your index.d.ts has the declare module statement in it...
// tsconfig.json
{
"compilerOptions": {
"target": "ESNEXT",
"module": "commonjs",
"outDir": "./dist",
"strict": true,
"esModuleInterop": true,
"forceConsistentCasingInFileNames": true
},
"include": [
// THIS IS WHAT FIXED IT
"test/index.d.ts"
]
}
// /test/index.d.ts
declare module 'test'
// /test/test.js
function test() {
console.log('test');
}
// Not sure if you're using `module.exports` or not
export default test;
// index.ts
import test from './test/test';
test()

TS2585: 'Promise' only refers to a type, but is being used as a value here

I'm getting the following error
node_modules/rxjs/internal/Observable.d.ts:82:59 - error TS2585: 'Promise' only refers to a type, but is being used as a value here. Do you need to change your target library? Try changing the lib compiler option to es2015 or later.
Formatted it looks like this,
node_modules/rxjs/internal/Observable.d.ts:82:59 - error TS2585: 'Promise' only refers to a type, but is being used as a value here. Do you need to change your target library? Try changing the `lib` compiler option to es2015 or later.
82 toPromise<T>(this: Observable<T>, PromiseCtor: typeof Promise): Promise<T>;
~~~~~~~
Found 1 error.
But the code I'm trying to run is right from the examples,
import { range } from 'rxjs';
import { map, filter } from 'rxjs/operators';
range(1, 200).pipe(
filter(x => x % 2 === 1),
map(x => x + x)
).subscribe(x => console.log(x));
I have in my tsconfig.json
"target": "ES2018",
"module": "es2015",
"lib": ["es2015"],
I'm running Rx.js 6.3.3, TypeScript 3.2.2 under Node v11.6.0. I've tried
npm i --save-dev #types/es6-promise
and just about every combination of changing lib and module
My ts config is exactly this,
{
"compilerOptions": {
/* Basic Options */
"target": "ES2016", /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
"module": "es2015", /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
"lib": ["es2016"], /* Specify library files to be included in the compilation. */
// "allowJs": true, /* Allow javascript files to be compiled. */
// "checkJs": true, /* Report errors in .js files. */
// "jsx": "preserve", /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
// "declaration": true, /* Generates corresponding '.d.ts' file. */
// "declarationMap": true, /* Generates a sourcemap for each corresponding '.d.ts' file. */
// "sourceMap": true, /* Generates corresponding '.map' file. */
// "outFile": "./", /* Concatenate and emit output to single file. */
// "outDir": "./", /* Redirect output structure to the directory. */
// "rootDir": "./", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
// "composite": true, /* Enable project compilation */
// "removeComments": true, /* Do not emit comments to output. */
// "noEmit": true, /* Do not emit outputs. */
// "importHelpers": true, /* Import emit helpers from 'tslib'. */
// "downlevelIteration": true, /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
// "isolatedModules": true, /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
/* Strict Type-Checking Options */
"strict": true, /* Enable all strict type-checking options. */
// "noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */
// "strictNullChecks": true, /* Enable strict null checks. */
// "strictFunctionTypes": true, /* Enable strict checking of function types. */
// "strictBindCallApply": true, /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
// "strictPropertyInitialization": true, /* Enable strict checking of property initialization in classes. */
// "noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */
// "alwaysStrict": true, /* Parse in strict mode and emit "use strict" for each source file. */
/* Additional Checks */
// "noUnusedLocals": true, /* Report errors on unused locals. */
// "noUnusedParameters": true, /* Report errors on unused parameters. */
// "noImplicitReturns": true, /* Report error when not all code paths in function return a value. */
// "noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */
/* Module Resolution Options */
"moduleResolution": "node", /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
// "baseUrl": "./", /* Base directory to resolve non-absolute module names. */
// "paths": {}, /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
// "rootDirs": [], /* List of root folders whose combined content represents the structure of the project at runtime. */
// "typeRoots": [], /* List of folders to include type definitions from. */
// "types": [], /* Type declaration files to be included in compilation. */
// "allowSyntheticDefaultImports": true, /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
"esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
// "preserveSymlinks": true, /* Do not resolve the real path of symlinks. */
/* Source Map Options */
// "sourceRoot": "", /* Specify the location where debugger should locate TypeScript files instead of source locations. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Emit a single file with source maps instead of having a separate file. */
// "inlineSources": true, /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
/* Experimental Options */
// "experimentalDecorators": true, /* Enables experimental support for ES7 decorators. */
// "emitDecoratorMetadata": true, /* Enables experimental support for emitting type metadata for decorators. */
}
}
Problem
TypeScript has two modes.
A project-builder mode (when tsc is invoked with no arguments)
A compile-mode (when tsc is invoked with any arguments) which does not read from the configuration file tsconfig.json
If that sounds confusing, it's even more confusing when you account for
the flag for the compiler-mode to accept a configuration file is called --project
inside the project-builder's configuration file there the pragma is called "compilerOptions"
the compiler-mode and the project-builder mode accept the same configuration file
Anyway, the problem here was that TypeScript was simply ignoring the configuration file in the current working directory that I was running it in.
If you want to see this changed vote here,
https://twitter.com/TheEvanCarroll/status/1080899909522477061
This is further reported here,
https://github.com/Microsoft/TypeScript/issues/29241
Just install #types/node from npm. This should solve the problem.
npm install #types/node
In my case I simply added a tsconfig.json file with the following contents where the significant part relating to the above error is "target": "es2015":
{
"compilerOptions": {
"noImplicitAny": false,
"noEmitOnError": true,
"removeComments": false,
"sourceMap": true,
"target": "es2015"
},
"include": [
"file.ts"
],
"exclude": [
"node_modules",
"wwwroot"
]
}
I've found this solution that worked for me:
Check if the tsconfig.json file has build in Properties set to "Content" rather than "None", if not right click on the tsconfig file and set the build action to Content. After this reload the project, the error should go away
Use this while compiling.
tsc async_await.ts --lib es2015

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