fix(plugin-content-docs): fix error message context (error cause) when doc processing fails

[shanpriyan]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

await the promise from doProcessDocMetadata and throw error if it fails

Test links

Deploy preview: https://deploy-preview-8234--docusaurus-2.netlify.app/

Related issues/PRs

Resolves #8230
Suggested fix #8230 (comment)

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 76	🟢 97	🟢 100	🟢 100	🟢 90	Report
/docs/installation	🟠 82	🟢 100	🟢 100	🟢 100	🟢 90	Report

[slorber]

good start thanks 👍

Can you also please add a unit test somewhere so that we be sure it works and never stops working again?

[shanpriyan]

Can you also please add a unit test somewhere so that we be sure it works and never stops working again?

Actually I'm not very familiar with writing tests 😅, If you could guide me I'll add it. Any links to similar tests would be appreciated

[slorber]

You can get inspiration from: https://github.com/facebook/docusaurus/blob/main/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts#L684

Create a md file with the bad frontmatter that should get rejected, then run the fn in a test and assert that the correct error message was thrown.

Run yarn test docs.test.ts --watch to run this specific test file. Jest provides it.only( and describe.only( to focus on a specific test case.

Actually I think some existing tests might cover the error message already, and will start failing with your fix because the message is now updated to something better: you may have to change the assertions/snapshots to reflect the change.

I'm not sure how Jest plays well with Error Cause, may have to look into it myself later. Let me know if you don't find a solution. If you want to contribute to open-source it will be important to be able to write tests so it's worth you give it a try ;)

[shanpriyan]

You can get inspiration from: https://github.com/facebook/docusaurus/blob/main/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts#L684

Create a md file with the bad frontmatter that should get rejected, then run the fn in a test and assert that the correct error message was thrown.

Run yarn test docs.test.ts --watch to run this specific test file. Jest provides it.only( and describe.only( to focus on a specific test case.

This would be helpful to get started, thanks

If you want to contribute to open-source it will be important to be able to write tests so it's worth you give it a try ;)

😄Will definitely consider your advice and I'll give this a try 🚀

[shanpriyan]

Actually I think some existing tests might cover the error message already, and will start failing with your fix because the message is now updated to something better: you may have to change the assertions/snapshots to reflect the change.

fixed existing test case (updated snapshot with latest error message) which failed due to change in error message

Before Fix	After fix

[shanpriyan]

@slorber since the below test case covers the latest error message (a532ed0), Do I need to add a new test case?

docusaurus/packages/docusaurus-plugin-content-docs/src/__tests__/docs.test.ts

Line 684 in e411332

it('docs with invalid id', async () => {

[slorber]

Thanks 👍

Fixed the test to assert that we have the full error cause chain being tested