many: allow for multiple documentations for a Unit

Change internal.Unit.Documentation from a single
internal.Documentation to a slice, so that a Unit can have doc for
multiple build contexts.

However, don't use this ability yet: fetch takes only the first
build context it finds, postgres inserts only the first, frontend
renders only the first, etc.

For golang/go#37232

Change-Id: I17fd1ff2378e0862c029c8077057c207001f6136
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/288217
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>
Reviewed-by: Jamal Carvalho <jamal@golang.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/internal/postgres/unit_test.go b/internal/postgres/unit_test.go
index 0a7ef993..9a2a73c8 100644
--- a/internal/postgres/unit_test.go
+++ b/internal/postgres/unit_test.go
@@ -626,7 +626,7 @@ func TestGetUnitFieldSet(t *testing.T) {
 	cleanFields := func(u *internal.Unit, fields internal.FieldSet) {
 		// Add/remove fields based on the FieldSet specified.
 		if fields&internal.WithMain != 0 {
-			u.Documentation = sample.Documentation
+			u.Documentation = []*internal.Documentation{sample.Documentation}
 			u.Readme = readme
 			u.NumImports = len(sample.Imports)
 			u.Subdirectories = []*internal.PackageMeta{
@@ -714,7 +714,7 @@ func unit(fullPath, modulePath, version, name string, readme *internal.Readme, s
 	if u.IsPackage() {
 		u.Imports = sample.Imports
 		u.NumImports = len(sample.Imports)
-		u.Documentation = sample.Documentation
+		u.Documentation = []*internal.Documentation{sample.Documentation}
 	}
 	return u
 }