fix #5 due to no esmodule

[parisholley]

No description provided.

[james-yeoman]

I've tried your fork, but you only have the fix for ESM. I'm using esbuild to bundle for serverless, which ends up being a CJS environment (node 18).

So I'm trying to bundle ESM to CJS, while importing a module that has a CJS file, which has a Zod import, which as we know, breaks instanceof checks.

Maybe it's worth adding an exports map? That might cause ESBuild to use the ESM version when importing, and compile it to CJS so that it shares the CJS Zod import?

Something like

"exports": {
	"types": {
		"import": "dist/esm/index.d.ts",
		"require": "dist/cjs/index.d.ts"
	}
	"import": "dist/esm/index.js",
	"require": "dist/cjs/index.js"
}

Alternatively, maybe Zod needs to be externalised? That would also solve the problem, because then ESBuild would be able to define Zod for this package, rather than this package having it's own Zod import.

I had a look at the build artifacts and Zod is already externalised.

So the problem stems from the fact that when targeting CJS (which is necessary when using the Serverless framework for deploying to AWS Lambda), the CJS version is being resolved.

So the only way I can see this problem being resolved is with the Exports map. The JS ecosystem has struck again ☹️

[james-yeoman]

Additionally, the ESBuild docs state the following

When the platform is set to node

The main fields setting is set to main,module. This means tree shaking will likely not happen for packages that provide both module and main since tree shaking works with ECMAScript modules but not with CommonJS

Unfortunately some packages incorrectly treat module as meaning "browser code" instead of "ECMAScript module code" so this default behavior is required for compatibility. You can manually configure the main fields setting to module,main if you want to enable tree shaking and know it is safe to do so.

Unfortunately for me, I'm unable to set the main fields setting to module, main. When I do so, some other package breaks, and my GraphQL Schema becomes invalid. Still not sure what's breaking, but it's not as simple as it seems

[james-yeoman]

I used yarn patch to try the exports map, and can confirm that it solves the ESBuild problem.

Suggested change

	"types": "dist/cjs/index.d.ts",
	"types": "dist/cjs/index.d.ts",
	"exports": {
	"types": {
	"import": "./dist/esm/index.d.ts",
	"default": "./dist/cjs/index.d.ts"
	},
	"import": "./dist/esm/index.js",
	"default": "./dist/cjs/index.js"
	},

[james-yeoman]

@parisholley I don't suppose you've got notifications disabled for this PR, have you? I can confirm that the exports map works perfectly