not able to setup assetTransformer in jest 26.x

Question

This is my assetTransformer used during my jest test runs.

    const path = require('path');
    
    module.exports = {
      process(src, filename, config, options) {
        const relativePath = path.relative(config.rootDir, filename);
        return `module.exports = ${JSON.stringify({testUri: relativePath})};`;
      },
    };

And configured in jest.config.js as

    moduleNameMapper: {
        "\\.(css|less)$": "identity-obj-proxy",
        "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/assetsTransformer.js",         
    },

My jest snapshot should atleast have the image path when used. Using "jest": "26.6.3",

My test output is coming with just a "process" method instead

Object {
    -   "testUri": "../../../src/assets/images/uncheck2.png",
    +   "process": [Function process],
      }

      309 |         const imgTick = getByTestId('imgTick');
      310 |
    > 311 |         expect(imgTick.props.source).toEqual({ testUri: '../../../src/assets/images/uncheck2.png' });
          |                                      ^
      312 |     })
      313 | });
      314 |