TypeError: TesseractWorker is not a constructor

[hussainhyder23]

const Worker= new TesseractWorker();//For analyzing images
^

TypeError: TesseractWorker is not a constructor
at Object. (/Users/hyder/Desktop/OCR-PDF/app.js:6:15)
at Module._compile (internal/modules/cjs/loader.js:774:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:785:10)
at Module.load (internal/modules/cjs/loader.js:641:32)
at Function.Module._load (internal/modules/cjs/loader.js:556:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:837:10)
at internal/main/run_main_module.js:17:11
[nodemon] app crashed - waiting for file changes before starting...

Please suggest a solution

[jeromewu]

Hi, may I know the version of tesseract.js you used?

[alexmorleyfinch]

I have a similar problem. My package.json has:

    "tesseract.js": "1.0.19",
    "tesseract.js-core": "1.0.2"

and if I nuke node modules and the package-lock and do npm install, I seem to get the v2 with the updated API. This may be a problem with npm or maybe my setup. Can anybody confirm?

[jeromewu]

To install v2, you need to add "next" tag in npm install

$ npm install tesseract.js@next

In the latest version (2.0.0-beta.1), TesseractWorker has deprecated and you need to use createWorker instead. Check README.md for details.

[alexmorleyfinch]

I forgot to actually write my problem, sorry. I am expecting npm to install version 1 (given that my package.json points to version 1), but for some reason npm installs version 2, even if I nuke and try again, I always get version 2 when I expect version 1. Thanks

[jeromewu]

Have you tried deleting package-lock.json and npm install to regenerate a new one?

[alexmorleyfinch]

Yes I have tried rm package-lock.json and rm -rf node_modules and npm install and I still get the problem. I do not have it globally installed either, so not sure what's going on

[alexmorleyfinch]

If, after an install I go to the package-lock.json and get the resolved url for tesseract.js, I get https://registry.npmjs.org/tesseract.js/-/tesseract.js-1.0.19.tgz as expected. However if I download the files from that link, I appear to get the latest code. The way I checked this was going to /dist/tesseract.js and seeing what gets exported. I got the line module.exports = create(); which I believe is for the latest code yes?

[jeromewu]

For the latest code, you can check here: https://unpkg.com/tesseract.js@2.0.0-beta.1/dist/tesseract.min.js

But I have to say the issue is not related to tesseract.js, you can check npm's github repo. here: https://github.com/npm/cli

[alexmorleyfinch]

Thanks for your help. I found the solution that I needed. You can close this issue now I think as this response should fix OP's problem: I needed these specific versions in my package.json.

    "tesseract.js": "2.0.0-alpha.13",
    "tesseract.js-core": "2.0.0-beta.11"

I needed these specific versions to get the version of the API that I originally coded to. I will move over to the latest v2 when ready, but for now this worked for me. Thanks for helping.

For anyone else reading, if you are getting the error TesseractWorker is not a constructor and you don't have time right now to update to the latest API, then use the above versions. It will work until you get time to update your code.

The reason this was a problem for me was because I coded to ^2.0.0-alpha.13 which means that when the owner made a new release and changed the API, any new deployments I made using npm install would install the new API, and all my code broke (which is my fault because I had ^2 in the package.json). It took me a while to realise which version I originally coded to. Once you remove the ^ though, then npm won't automatically get the latest.

Note: You should probably update your codebase rather than linking to a specific alpha build, but until you get time to do that, this should work for you.

[jeromewu]

Glad that there is a solution, close the issue for now, @hussainhyder23 feel free to reopen with more information.

[exaland]

@alexmorleyfinch Thanks your solution works for me 👍

[ABHISHEK-AMRUTE]

@alexmorleyfinch still getting the error.

[jaskirat1313]