x/website: make it safer to make changes to templated HTML pages

[dmitshur]

Issue #37072 was about making it safer to make changes to draft release notes. But the golang.org website (and in turn, the tip copy at tip.golang.org) still has many pages that use templates.

Right now, if a change introduces an error on one of the templated pages, there isn't a test or trybot that catches that error. We should find a way to automate finding this kind of a problem, otherwise it can lead to broken pages on golang.org (when manually deployed, if the deployment regression tests don't catch it) and tip.golang.org (which is automatically deployed as soon as the CL is submitted).

See CL 217877 and CL 218217 for a recent occurrence that should ideally be caught in the future.

/cc @bcmills @golang/osp-team

[gopherbot]

Change https://golang.org/cl/229079 mentions this issue: content: convert doc/{conduct,security}.html to non-template

[gopherbot]

Change https://golang.org/cl/229081 mentions this issue: cmd/golangorg: generate release history page from structured data

[jba]

I just wrote templatecheck, a package that validates templates after they are parsed. It might help with this issue.

[gopherbot]

Change https://go.dev/cl/393357 mentions this issue: internal/history: split Release summary into bug- and security fixes

[dmitshur]

The original issue stated:

Right now, if a change introduces an error on one of the templated pages, there isn't a test or trybot that catches that error.

This is no longer the case today. As documented in golangorg's README, x/website now has tests that check various pages for expected status code and content. If a template error is introduced, those tests will fail and will be caught by TryBots, or during deployment (if TryBots were accidentally missed).

Closing as fixed. Thanks to Russ who authored the webtest package and its integration into deployment.