cmd/golangorg: document screentest in README
Change-Id: I4e5dee5e8da28e7dd4d209b27a9febb13ef42105
Reviewed-on: https://go-review.googlesource.com/c/website/+/377354
Trust: Jamal Carvalho <jamalcarvalho@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/cmd/golangorg/README.md b/cmd/golangorg/README.md
index 6ecab93..38fd55f 100644
--- a/cmd/golangorg/README.md
+++ b/cmd/golangorg/README.md
@@ -24,6 +24,16 @@
and used only when testing a live server, because its test cases depend
on production resources.
+## Screentest
+
+The go.dev web site has a suite of visual checks that can be run with:
+
+ go run ./cmd/screentest
+
+These checks can be run locally and will generate visual diffs of web pages
+from the set of testcases in `cmd/screentest/godev.txt`, comparing screenshots
+of the live server and a locally running instance of cmd/golangorg.
+
## Deploying to go.dev and golang.org
Each time a CL is reviewed and submitted, the site is automatically deployed to App Engine.
