Use eleventyDataSchema in Data Cascade to validate data

[pdehaan]

https://www.11ty.dev/docs/config/#linters are super cool, but I was hoping to have a linter for the raw input files so I could do a front-matter linter which would throw errors or otherwise report if a file was missing a "required" field in a file's front-matter.

Is something like that possible, or should I try and do that while defining a custom collection?
Or should it be something that I write separately using glob and grey-matter as a separate script?

[zachleat]

You could do this with the new #1206 access to rawInput and that might be the best option for now. Filing this as an enhancement request!

Marginally related to #867!

This repository is now using lodash style issue management for enhancements. This means enhancement issues will now be closed instead of leaving them open.

View the enhancement backlog here. Don’t forget to upvote the top comment with 👍!

[zachleat]

Seems related to #3251 too

[zachleat]

This is shipping in 3.0.0-alpha.7 as the eleventyDataSchema property (function callback, async-friendly) in the data cascade. Here’s an example using zod in a directory data file (e.g. blog.11tydata.js) that checks to make sure a draft property is boolean:

import { z } from "zod";
import { fromZodError } from 'zod-validation-error';

export default {
	eleventyDataSchema: function(data) {
		let result = z.object({
			draft: z.boolean().or(z.undefined()),
		}).safeParse(data);

		if(result.error) {
			throw fromZodError(result.error);
		}
	}
};

[zachleat]

Shout out to https://github.com/uncenter/eleventy-plugin-validate by @uncenter

[uncenter]

Shout out to uncenter/eleventy-plugin-validate by @uncenter

Thanks! While we are on this topic... is there an easier way to narrow down the source of data? I'm using item.template._frontMatter?.data at the moment to just look at front matter and I can't tell if this new feature lets me do that or not.

[uncenter]

is shipping in 3.0.0-alpha.7 as the eleventyDataSchema property (function callback, async-friendly) in the data cascade. Here’s an example using zod in a directory data file (e.g. blog.11tydata.js) that checks to make sure a draft property is boolean:

Looks like my little hack to access specifically front matter data got removed... 70df967#r141478000. It would be nice to be able to still, maybe with an unprefixed property?

[kfranqueiro]

Adding a comment here RE https://fosstodon.org/@eleventy/112446508013942858

Piggybacking on the Zod example above: Zod supports a couple of data-massaging features such as coercion and transforms, which result in the output differing from the input.

It would be great to be able to take advantage of these features via elventyDataSchema as well - for example, this could be used to coerce computed template strings in front matter to other types. However, IIUC eleventyDataSchema currently treats the validation as a read-only operation, incapable of overriding the original data?

(It's potentially worth noting for this use case that Zod's parse functions strip keys not found in the schema by default, but they can be kept using passthrough())

[zachleat]

@uncenter I think you want this comment here:

eleventy/src/TemplateContent.js

Line 155 in d30b952

"Unfortunately you’re using code that monkey patched some Eleventy internals and it isn’t async-friendly. Change your code to use the async `read()` method on the template instead!",

let {data} = await item.template.read();

(it should reuse the cached read promise, if any exists)

[uncenter]

@uncenter I think you want this comment here:

eleventy/src/TemplateContent.js

Line 155 in d30b952

"Unfortunately you’re using code that monkey patched some Eleventy internals and it isn’t async-friendly. Change your code to use the async `read()` method on the template instead!",

let {data} = await item.template.read();

(it should reuse the cached read promise, if any exists)

Thank you! Updated the plugin and now it works with the latest canary! 🤩

[zachleat]

Preview docs building here: https://11ty-website-git-v3-11ty.vercel.app/docs/data-validate/