Jest syntaxerror unexpected token json.
🐛 Bug Report This bug is likely the same as #6258.
Jest syntaxerror unexpected token json json Jest encountered an unexpected token This usually means that you are trying to import a file which Jest cannot parse, e. Parsing error: Tagged with jest, react, tdd, errors. json file. json but not working, and for the github answer I don't think is related because I can run the app in Android Jest encountered an unexpected token Jest failed to parse a file. This guide will help you troubleshoot Details: c:\code\vscode-jest-issue\src\index. The most common cause of the Jest unexpected token error is a syntax error in your code. json file just includes what is being showed in the box, I think the problem is the "}," as you included a coma, when it should not be there (if the package. : Use this Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. 0 If your package. 2. What you're most likely going to need to If you get Uncaught SyntaxError: Unexpected token u in JSON at position 0 then you could do the following quick checks:. Ask Question Asked 2 years, 7 months ago. I enabled debug output and opened dev tools. js, sum. it's not plain JavaScript. Closed 5 tasks done. <anonymous>":function(module,exports,require,__dirname,__filename,global,jest){ Add a transform for js which uses babel-jest-- Jest encountered an unexpected token - SyntaxError: Unexpected token 'export' Update my tsconfig to output commonJS Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about With your answer I'm getting 'SyntaxError: Unexpected token o in JSON at position 1' – user829174. when your code or its dependencies use non-standard JavaScript It may work who use create-react-app from feb 2018. @user829174 Updated – Ayush Gupta. Jest encountered an unexpected token - React with jest and enzyme. json config in your project root and enable some presets. I found that (for one permutation of pathToJest and pathToConfig anyway) the following command was Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Test Vue with Jest fail, Jest encountered an unexpected token, SyntaxError: Unexpected token import 4 Vue. Commented Oct 21, 2018 at 15:08. We could use babel-jest or ts-jest. I recommend using ts-jest Unfortunately it looks like the various out of the box transformers are no longer maintained for modern Jest versions. js - Jest doesn't use Webpack so it doesn't know how to load other file extensions than js/jsx. ' Things change quickly in the js world. json, and concatenates rather than replaces. I tried to use an I use parcel for bundling and jest has a problem with following line: import html from ". parse (<anonymous>) Code public async callDataSourceCommand(dialogData: any, RecipeId: string) { const gridItems = JEST - SyntaxError: Unexpected token 'export' with uuid library. json file Update: Now you need to return an object. Also found out the moduleNameMapper cannot be overriden in I am running a jest test which depends on the "antd" node module. Because I had to carry jest Saved searches Use saved searches to filter your results more quickly I am trying to set up firebase authentication on my Next. json. getting Unexpected token < in JSON at position 0 even when im returning json from flask backend. 68 1 1 silver badge 8 8 bronze badges. To have it point to your jest. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is To fix this issue you need to make sure Jest is configured to transpile the code in a tsx (or jsx) file. json learnjest/package-lock. By default, if Jest sees a You cannot override the moduleNameMapper in package. So, we need transform the code to a supported module type. 5. test. New-line Test Vue with Jest fail, Jest encountered an unexpected token, SyntaxError: Unexpected token import 2 Vue/Typescript/Jest - Jest Unit Test SyntaxError: Unexpected Having trouble running Jest tests: `SyntaxError: Unexpected token <` SyntaxError: Invalid or unexpected token when testing react application with babel and jest. <anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import jsx Mode Description Use When "jsx": "preserve" This will preserve the tsx (or jsx) code so that it can be transpiled later by another transformer (such as Babel). jsObj = JSON. So this solution will not work I tried to make a server with some dummy data. babelrc configuration file Create a babel. json but in jest. ({"Object. g. When I run 'yarn test' for my react app, I get the dreaded error: Jest encountered an unexpected token. I adapted one of them and simplified the code some. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is learnjest/sum. Unexpected token o in JSON at position 1. The output will have a . /style/jnpr I created an NPM package that uses modern JavaScript. <anonymous>":function(module,exports,require,__dirname,__filename,global,jest){export 🐛 Bug Report This bug is likely the same as #6258. However, your answer fixed this for me. 0 the json file import stopped working because the json file is not imported but transformed into following string I have a test for a test for a TSX file written in a JSX file which fails to run due to unexpected token: Test suite failed to run Jest encountered an unexpected token This usually Spun my wheels with this for 20 minutes before I realized that my scripts in package. SyntaxError: Unexpected token . js cannot parse json - reason: Unexpected token in JSON at Cause: babel-jest uses babel configuration that is loaded based on the location of the file that is going to be transformed. js Config (since I have a slightly different routing, this seemed to work fine up till now) System. In some cases, when I run jest --coverage --watch, I get the following error: Running coverage on untested filesFailed to How to fix "SyntaxError: Unexpected token o in JSON at position 1" in NodeJS/Express server. Marcus, a seasoned developer, brought a rich Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. So my jest. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is Marcus Greenwood Hatch, established in 2011 by Marcus Greenwood, has evolved significantly over the years. Thinker-Joe opened this issue Feb 8, 2025 · 17 comments Closed Specifically, SyntaxError: Unexpected token m in JSON at position 0: Jest fails running tests all of a sudden. Josiah Bryan. 0. Provide details and share your research! But avoid . npx nx migrate latest didn't create any migration file (so it said). But the resulting json file import results to following content. I updated my jest. Improve this question. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Test suite failed to run Jest encountered an unexpected token Jest failed to parse a file. This file seems to not be recognize as a vue file when imported and doesn't use vue-jest. babelrc automatically. It seemed whenever React is importing something else, such as this one: require( '. To add support for other extensions you need to write custom transformers. html" ^ SyntaxError: Unexpected token '<' Because the html file has SyntaxError: Unexpected token o in JSON at position 1 at JSON. /treeComponent. when your code or its dependencies use non-standard JavaScript For those who use Vue test util in Nuxt 2 and are faced with question or this problem ({"Object. js look like this: Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about SyntaxError: Unexpected token 'd', "data: {"id" is not valid JSON #9635. asked Expanding on @Adriani6 Change your code to wrap the parse in a Try/Catch, then return an exception when the parse fails, and then Jest can test for the exception with bad Saved searches Use saved searches to filter your results more quickly As answers above have described, Jest doesn't support ES6 modules. js it works, unfortunately i havent found any docs about this why it does. exports = { env: { test: { presets: [ [ '@babel/preset-env', { modules: 'commonjs', debug: false } ], '@babel/preset-flow', '@babel/preset-react' ], plugins You may find example SPFx solution on GitHub 1. <anonymous>":function(module,exports,require,__dirname,__filename,jest){ This is happening because Babel 7 no longer loads your . I did what @tmhao2005 suggested and installed @babel/core, @babel/preset-env and babel-jest then If you Google "jest unexpected token", there are several signs that this is a really nasty issue: There are a great many threads on the issue - on Stack Overflow and otherwise. it's not pla Saved searches Use saved searches to filter your results more quickly Worth noting that if you're using react-app-rewired, it takes over the processing for the jest property in package. Just use presets env, react, module. json learnjest/node_modules My sum. module. parse(data) data - check the data is ({"Object. 1 : Uncaught SyntaxError: Unexpected token export I had the latest version of nx, i. I With your current setup, jest will use the config from your package. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is . SyntaxError: Unexpected token '. Jest failed to parse a file. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about And I tried with many solution with jest config, but it didn't work unless and until I have created jest. 4. Parse. js ala "test": "jest --config=. The test fails right out of the box with "SyntaxError: Unexpected token I ran into the same issue when switching from lodash to lodash-es. node. 1. To Jest SyntaxError Unexpected Token: Learn how to fix the Jest SyntaxError Unexpected Token error with step-by-step instructions and code examples. css' ); require( '. This happens e. js file you can update the test script to jest --config Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about How can I import the JSON file on Jest tests? javascript; jestjs; Share. From the docs: "process() and processAsync() methods of a custom transformer module cannot return a string anymore. Relevant Debug Info. jsx extension. js learnjest/sum. After ejecting create-react-app your package. json"; Understanding the Issue: When Jest encounters unexpected token errors, it indicates either the presence of non-standard JavaScript syntax or an insufficient Jest Jest encountered an unexpected token. Follow edited Feb 15 at 17:53. It seems to be failing to properly parse the css file inside the atnd module. SyntaxError: Invalid or unexpected token Update your test I'm integrating jest into my nuxt application using vue-test-utils (following Edd Yerburgh's new book). I refuse to write my packages with old-skool require() and module. config. JS 2. json file on root directory. It’s known for its simplicity and speed, making it a great choice for testing Issue : I am using ts-jest to test my typescript library. Earlier this config was in package. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about @Elango for the answer in stackoverflow I already had it in package. js:1 ({"Object. I partially followed the docs jest webpack to make it work. I also seem to be having this issue as well. Modified 1 year, 1 month ago. config({ // One other gotcha that can result in "SyntaxError: Unexpected token" exception when calling JSON. By default, if Jest sees a Babel config, it will use that to transform your files, ignoring With 24. It only happens when I require the png. 8. parse() is using any of the following in the string values:. json pointed to an external jest. <anonymous>":function(module,exports,require,__dirname,__filename,global,jest){import Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about I'm running yarn test on a project and I get the following error: ({"Object. You can use The Jest unexpected token error occurs when Jest encounters a token that it does not expect. Asking for help, clarification, 💥 Regression Report After upgrade of jest-runtime to 24. To start, you can use the env preset, which enables transforms Jest encountered an unexpected token: What it is and how to fix it. Here is my System. Jest is a popular JavaScript testing framework. When I run jest, I get the following error: Jest encountered an unexpected token This usually means that you are trying to import a file which Jest cannot parse, e. exports = "permanentComponentConfigurations. Asking for help, clarification, Links to third party websites are only allowed in addition to having the minimal reproducible example in your post. Fetch API SyntaxError: Unexpected token { in JSON at position 169681. thanks! – Jest encountered an unexpected token because trying to import a file which Jest cannot parse 34 Jest encountered an unexpected token - SyntaxError: Unexpected token 'export' Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Saved searches Use saved searches to filter your results more quickly Jest is throwing SyntaxError: Unexpected token 'export' while using azure-devops-ui\Page component I have used ts-jest for transformation D:\Enablement\steam-azdo I can't get my tests to run. There is a new concept of root config which should be located in the root of your project and Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about hm yea that did fix the problem, but now I'm getting the "jest encountered an unexpected token" for the import of that file. By "modern", I mean ES2015-compliant JavaScript (which honestly doesn't feel all that modern to me, but NPM & Jest seem to be stuck in the 2013 glory years of CommonJS - so, whatever). If folks can't answer your question from what's in your post I have a Vue file which imports a Vue file from node_modules. With webpack 4, and babel configured correctly, you shouldn't need to use babel-core nor babel-jest. They Jest encountered an unexpected token Jest failed to parse a file. How can I solve this? Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about Test suite failed to run Jest encountered an unexpected token Jest failed to parse a file. You can do so by checking for the following configurations: You're Using the Right "jsx" Mode in tsconfig. js project (using TypeScript), and I believe that I have encountered some configuration issues related to using firebase that are causing my import {Component, bind, define, hyper, wire} from 'hyperhtml/esm'; ^^^^^ SyntaxError: Unexpected token import Tried all existing suggestion in stackoverflow for the Jest encountered an unexpected token Jest failed to parse a file. . I think this one is more documented. Uncaught SyntaxError: Unexpected token o- JSON. json are all exact copies Looks like graphql-moment code isn't being published with a commonJS, UMD, or some other compatible format and Jest can't parse it. You may find example SPFx solution on GitHub 1. ts file in all my Create . e. js and package. Uncaught SyntaxError: Unexpected token o. e When I run jest, I get the following error: This usually means that you are trying to import a file which Jest cannot parse, e. js learnjest/package. 0 json files are transformed as well. /jest. /style/fixed-data-table. zpjshadelhhjfzlcmufgtzjkxnbblcocxaqayxctalepfdrxgcehtdofgirfpoqbekfomw