💡 RFC: Add support for autocompletion and type-checking for Content collections in MD and MDX files

[TechAurelian2]

Background & Motivation

When adding or editing a content entry (a Markdown (.md) or MDX (.mdx) file) from a content collection that has a collection schema, I would like VSCode to let me know when the frontmatter does not match the collection schema and help me fill the frontmatter based on the schema.

It should:

• suggest or autocomplete the available frontmatter properties defined in the collection schema
  (e.g., if I start typing sort I should get autocompletion for sortOrder because it is defined in the collection schema)

• show errors if I type a frontmatter property that is not defined in the collection schema
  (e.g., if I type undefinedField: true, because undefinedField is not defined in the schema)

• show errors if I type a wrong type of value for a property
  (e.g., if I type sortOrder: some text, because sortOrder should be a number)

• show any missing frontmatter properties that are required by the collection schema
  (e.g., if I forget to define the title property, and title is a required property in the schema, not optional)

Sample collection schema for the above examples:

const sampleCollection = defineCollection({
  schema: z.object({
    title: z.string(),
    sortOrder: z.number(),
    …
  }),
});

Proposed Solution

Possible solutions

Using an existing Markdown/MDX linting extension and adding the Astro content collection checks?

Alternatives considered

Switch to the browser to see any content collection schema errors in the new Error Overlay, then open the misbehaving content entry in VSCode, fix the issue, save, and repeat. But this can be a tedious process, especially after importing a large number of content entries that need fixing.

Risks, downsides, and/or tradeoffs

None that I can see

Open Questions

N/A

Detailed Design

No response

Help make it happen!

• I am willing to submit a PR to implement this change.
• I am willing to submit a PR to implement this change, but would need some guidance.
• I am not willing to submit a PR to implement this change.

[Hubro]

A code action to add all the properties to the front matter would be freaking huge