ES Modules broken on npm@7

[richardsimko]

Environment

Knex version: 0.21.17
Database + version: N/A
OS: N/A

Bug

1. Explain what kind of behaviour you are getting and how you think it should do

When setting type: 'module' in package.json knex fails to use ESM to load the migration files on npm >= 7.0.0. This works on lower versions. The reason being that npm has removed the environment variable which knex uses to determine if it should use ESM or CommonJS (

knex/lib/migrations/util/import-file.js

Line 2 in b20a31f

const isTypeModule = process.env.npm_package_type === 'module';

). See this NPM RFC for more details https://github.com/npm/rfcs/blob/a044b355af60310b05ad1995fdc1cf672243a4e0/implemented/0021-reduce-lifecycle-script-environment.md. If the file is named knexfile.mjs it works as expected since the filename check triggers the usage of ESM.

2. Error message

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /project-root/config/knexfile.js
require() of ES modules is not supported.
require() of /project-root/node_modules/knex/lib/util/import-file.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename knexfile.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from /project-root/package.json.

    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1080:13)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at importFile (/project-root/node_modules/knex/lib/util/import-file.js:13:7)
    at openKnexfile (/project-root/node_modules/knex/bin/cli.js:26:22)
    at initKnex (/project-root/node_modules/knex/bin/cli.js:47:13)
    at Command.<anonymous> (/project-root/node_modules/knex/bin/cli.js:170:32)
    at Command.listener [as _actionHandler] (/project-root/node_modules/commander/index.js:426:31)

3. Reduced test code, for example in https://npm.runkit.com/knex or if it needs real
   database connection to MySQL or PostgreSQL, then single file example which initializes
   needed data and demonstrates the problem.

All that's needed is a project with type: 'module' in the package.json and a knexfile ending in .js.

npm's recommended migration route is to use the variable npm_package_json which points to the package.json, load the JSON and then read values from there.

[kibertoad]

@richardsimko Uh-oh, thank you for pointing out the issue! Would you consider sending a PR with a fix?

[richardsimko]

Sure, I can probably put something together. Just in case anyone else stumbles on this before a fix is released, a workaround is to change the knexfile to end with .mjs.

[richardsimko]

@kibertoad I opened #4296

[kibertoad]

Released in 0.95.0-next2

[kibertoad]

Released in 0.21.18