_content/doc/go1.24: add release date

The month and year alone should be enough granularity for the purpose
of the introduction to Go 1.24. In this case, February 2025 refers to
when the go1.24.0 major release came out, but we released pre-release
versions even before then. Link to the dedicated release history page
where full details and exact dates can be found.

Add a test so we don't forget.

For golang/go#68545.
Fixes golang/go#54170.

Change-Id: Ia2bceee9208094b0623add6696585592f4399893
Reviewed-on: https://go-review.googlesource.com/c/website/+/654015
Reviewed-by: Ian Lance Taylor <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: dmitshur

_content/doc/go1.24.md

@@ -9,7 +9,9 @@ template: false
 
 ## Introduction to Go 1.24 {#introduction}
 
-The latest Go release, version 1.24, arrives six months after [Go 1.23](/doc/go1.23).
+The latest Go release, version 1.24,
+arrives in [February 2025](/doc/devel/release#go1.24.0),
+six months after [Go 1.23](/doc/go1.23).
 Most of its changes are in the implementation of the toolchain, runtime, and libraries.
 As always, the release maintains the Go 1 [promise of compatibility](/doc/go1compat).
 We expect almost all Go programs to continue to compile and run as before.

cmd/golangorg/server_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 	"go/build"
+	"io/fs"
 	"net/http/httptest"
 	"net/url"
 	"os"
@@ -18,6 +19,8 @@ import (
 	"testing"
 
 	"golang.org/x/net/html"
+	"golang.org/x/website"
+	"golang.org/x/website/internal/history"
 	"golang.org/x/website/internal/webtest"
 )
 
@@ -319,3 +322,30 @@ func findAttr(n *html.Node, name string) string {
 	}
 	return ""
 }
+
+// TestReleaseNotesHaveDate tests that release notes
+// include the date of the corresponding major release.
+// See go.dev/issue/54170.
+func TestReleaseNotesHaveDate(t *testing.T) {
+	for _, r := range history.Majors {
+		if r.Version.Before(history.Version{X: 1, Y: 24}) {
+			// No dates in release notes before Go 1.24.
+			break
+		}
+		maj := r.Version.MajorPrefix()
+		t.Run(maj, func(t *testing.T) {
+			name := fmt.Sprintf("doc/go%s.md", maj)
+			have, err := fs.ReadFile(website.Content(), name)
+			if err != nil {
+				t.Fatalf("Go %s release notes (_content/%s) can't be read: %v", maj, name, err)
+			}
+			want := fmt.Sprintf("[%s %d](/doc/devel/release#go%s)", r.Date.Month, r.Date.Year, r.Version)
+			if r.Future {
+				want = fmt.Sprintf("%s %d", r.Date.Month, r.Date.Year)
+			}
+			if !strings.Contains(string(have), want) {
+				t.Errorf("Go %s release notes (_content/%s) doesn't contain the release date and link to release history page %q", maj, name, want)
+			}
+		})
+	}
+}