Have this error (Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/oluwasetemi/Development/projects/contractors/groovy/groovy_backend/node_modules/remark/index.js require() of ES modules is not supported.) using remark with typescript

[Oluwasetemi]

I was trying to create an html document that can be served using an express route with remark and I ran into this error and I don't know what can be done to resolve this issue. My app is a typescript based express rest api.

this is a code snippet of what I am doing.

import { remark } from 'remark';
import remarkHtml from 'remark-html';
import recommended from 'remark-preset-lint-recommended';
import { reporter } from 'vfile-reporter';

app.get('/changelog', async (req, res) => {
    // read file
    const changeLogString = await readFileSync(path.join(__dirname, '..', 'changelog.md'), 'UTF-8');
    // parse the string of the file to html

    remark()
	.use(recommended)
        .use(remarkHtml)
	.process(changeLogString, function (err, file) {
		console.error(reporter(err || file));				
		return res.send(String(file));
    });
});

node version 14.17.0
ts-node: 10.1.0,
typescript: 4.3.5

my ts config

{
	"compilerOptions": {
		/* Visit https://aka.ms/tsconfig.json to read more about this file */
		"sourceMap": true,
		"outDir": "dist",
		"lib": ["ESNext"],

		/* Basic Options */
		// "incremental": true,                         /* Enable incremental compilation */
		"target": "es5" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', 'ES2021', or 'ESNEXT'. */,
		"module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
		// "lib": [],                                   /* 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', 'react', 'react-jsx' or 'react-jsx'. */
		// "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 */
		// "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
		// "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": false /* Enable strict null checks. */,
		// "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
		// "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
		"strictPropertyInitialization": false /* Enable strict checking of property initialization in classes. */,
		"suppressImplicitAnyIndexErrors": false,
		// "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. */
		// "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
		// "noImplicitOverride": true,                  /* Ensure overriding members in derived classes are marked with an 'override' modifier. */
		// "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */

		/* 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": [
			"./",
			"./node_modules/@types",
			"./@typings"
		] /* List of folders to include type definitions from. */,
		// "types": ["jest", "index.d.ts"] /* 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. */
		// "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */

		/* 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. */

		/* Advanced Options */
		"skipLibCheck": true /* Skip type checking of declaration files. */,
		"forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
	},
	// "./",
	"include": ["src", "index.ts", "index.d.ts", "@types"],
	"exclude": ["node_modules", "**/*.spec.ts", "**/*.test.ts"]
}

Any one with a good idea of what I am doing wrongly.

[Oluwasetemi]

if the contributors think I should create an issue is the solution please let me know as well.

[ChristianMurphy]

The issue is coming from the tsconfig.json, see https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#im-having-problems-with-esm-and-typescript

If you have decided to make your project ESM ("type": "module" in your package.json), make sure you have "module": "ES2020" in your tsconfig.json and that all your import statements to local files use the .js extension, not .ts or no extension.

[Oluwasetemi]

Does that mean that all import to local files must be changed to .js or no extension

[ChristianMurphy]

It does

[sodhisaab]

Guys, I am facing the same problem.

I tried option 1 and getting the following error

with options, 2 -> build is working but page not found

with option 3

any idea guys, I am unable to update to the latest version

Thank you

[ChristianMurphy]

@sodhisaab it looks like you are using Next.js?
The setup for Next is different than Express, see https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#im-having-problems-with-esm-and-nextjs for usage with Next.

[sodhisaab]

Thank you, I manged to fix it 😉 thank you once again