Extensionless layout in 2.0 canary 20

[flaviotordini]

Operating system

macOS

Eleventy

2.0.0-canary.20

Describe the bug

I'm using liquid layout names without extension.

    eleventyConfig.setLiquidOptions({
        extname: ".liquid"
    });

Just updated to canary 20 and got this error:

[11ty] You’re trying to use a layout that does not exist: base (undefined) (via Error)
  Eleventy:EleventyErrorHandler (error stack): Error: You’re trying to use a layout that does not exist: base (undefined)
  Eleventy:EleventyErrorHandler     at TemplateLayoutPathResolver.getFullPath (/Users/.../node_modules/@11ty/eleventy/src/TemplateLayoutPathResolver.js:102:13)

Reproduction steps

No response

Expected behavior

No response

Reproduction URL

No response

Screenshots

No response

[pdehaan]

See #2700

[zachleat]

Whew, a few more of these and I will revert the default 😅

[zachleat]

https://www.11ty.dev/docs/layouts/#omitting-the-layouts-file-extension

[flaviotordini]

Thanks! I missed that.

[reubenlillie]

Whew, a few more of these and I will revert the default 😅

@zachleat, I think there just needs to be a really clear notice, since it's a potentially breaking change. Maybe a clearer error message like "It looks like the layout file you specified is missing a file extension."

If memory serves, previous documentation made it sound like omitting the file extension was a preferable, nifty feature, to promote Eleventy's flexible templating language options. I agree that specifying an extension is a significant performance improvement. If there is a default that can forego specification, it should be *.11ty.js (though I'm obviously biased).

[pdehaan]

@zachleat What about reverting the build error and seeing if we can flag it as a noisy warning in https://github.com/11ty/eleventy-upgrade-help and possibly say we'll change the default behavior in 2.1 or 3.0.

Not sure if we need to add that eleventy-upgrade-help plugin to the https://www.11ty.dev/docs/ sidebar to increase visibility (since I knew about it, but still took some googling to find it).

[zachleat]

Restoring this in #2708! This is more popular than I thought 😅

[paulshryock]

I do like the change to require the extension, and I agree that a more clear error message explaining that the file extension is missing would make it easier. I mean that's the point of a canary/alpha release is that there will be API-breaking changes as the design is iterated on.