Fix for ERR_MODULE_NOT_FOUND within lambda node14.x runtime

[hicksy]

Having been working locally without issue, I've now deployed to an AWS lambda function using the node14.x runtime.

As I'm working in node14 my code uses import statements, rather than require. e.g. import {Table, Model} from 'dynamodb-onetable';

Invoking the lambda I receive an ERR_MODULE_NOT_FOUND not found error:

{
    "errorType": "Error",
    "errorMessage": "Cannot find module '/var/task/node_modules/dynamodb-onetable/dist/mjs/Expression' imported from /var/task/node_modules/dynamodb-onetable/dist/mjs/index.js",
    "code": "ERR_MODULE_NOT_FOUND",
    "stack": [
        "Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/var/task/node_modules/dynamodb-onetable/dist/mjs/Expression' imported from /var/task/node_modules/dynamodb-onetable/dist/mjs/index.js",
        "    at finalizeResolution (internal/modules/esm/resolve.js:276:11)",
        "    at moduleResolve (internal/modules/esm/resolve.js:699:10)",
        "    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:810:11)",
        "    at Loader.resolve (internal/modules/esm/loader.js:86:40)",
        "    at Loader.getModuleJob (internal/modules/esm/loader.js:230:28)",
        "    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:56:40)",
        "    at link (internal/modules/esm/module_job.js:55:36)"
    ]
}

I'm not entirely certain why this works for me locally (maybe I'm running --experimental-specifier-resolution=node flag 🤷‍♂️). But it seems the lambda node14.x runtime definitely doesn't allow ESM imports without the file extension.

Modified src/index.js to specify the file extensions which resolved my issue.

[mobsense]

Thank you. That is right.