internal/frontend: add deprecated/retracted info to versions

For golang/go#43265
For golang/go#41321

Change-Id: I1c53af8cd04ec0d3d2b13874cd028a3f97b5101b
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/297509
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>

content/static/html/helpers/_versions.tmpl

@@ -4,6 +4,8 @@
   license that can be found in the LICENSE file.
 -->
 
+{{/* . is internal/frontend.VersionsDetails */}}
+
 {{define "versions"}}
   <div class="Versions">
     <table>
@@ -24,15 +26,24 @@
   </div>
 {{end}}
 
+
+{{/* . is []*internal/frontend.VersionList */}}
+
 {{define "module_list"}}
   {{range $major := .}}
      {{range $i, $v := $major.Versions}}
        <tr>
          <td>
-           {{if eq $i 0 }}<div class="Versions-major">{{$major.Major}}</div>{{end}}
+           {{if eq $i 0 }}
+             <div class="Versions-major">
+               {{$major.Major}}
+               {{if $major.Deprecated}}(Deprecated{{with $major.DeprecationComment}}: {{.}}{{end}}){{end}}
+             </div>
+           {{end}}
          </td>
          <td>
            <a href="{{$v.Link}}">{{$v.Version}}</a>
+           {{if $v.Retracted}}(Retracted{{with .RetractionRationale}}: {{.}}){{end}}{{end}}
          </td>
          <td>
            <div class="Versions-commitTime">{{$v.CommitTime}}</div>

internal/frontend/versions.go

@@ -14,6 +14,7 @@ import (
 	"golang.org/x/mod/module"
 	"golang.org/x/mod/semver"
 	"golang.org/x/pkgsite/internal"
+	"golang.org/x/pkgsite/internal/experiment"
 	"golang.org/x/pkgsite/internal/log"
 	"golang.org/x/pkgsite/internal/postgres"
 	"golang.org/x/pkgsite/internal/stdlib"
@@ -51,6 +52,11 @@ type VersionListKey struct {
 	// Incompatible indicates whether the VersionListKey represents an
 	// incompatible module version.
 	Incompatible bool
+
+	// Deprecated indicates whether the major version is deprecated.
+	Deprecated bool
+	// DeprecationComment holds the reason for deprecation, if any.
+	DeprecationComment string
 }
 
 // VersionList holds all versions corresponding to a unique (module path,
@@ -67,8 +73,10 @@ type VersionList struct {
 type VersionSummary struct {
 	CommitTime string
 	// Link to this version, for use in the anchor href.
-	Link    string
-	Version string
+	Link                string
+	Version             string
+	Retracted           bool
+	RetractionRationale string
 }
 
 func fetchVersionsDetails(ctx context.Context, ds internal.DataSource, fullPath, modulePath string) (*VersionsDetails, error) {
@@ -92,7 +100,7 @@ func fetchVersionsDetails(ctx context.Context, ds internal.DataSource, fullPath,
 		}
 		return constructUnitURL(versionPath, mi.ModulePath, linkVersion(mi.Version, mi.ModulePath))
 	}
-	return buildVersionDetails(modulePath, versions, linkify), nil
+	return buildVersionDetails(ctx, modulePath, versions, linkify), nil
 }
 
 // pathInVersion constructs the full import path of the package corresponding
@@ -119,7 +127,7 @@ func pathInVersion(v1Path string, mi *internal.ModuleInfo) string {
 // versions tab, organizing major versions into those that have the same module
 // path as the package version under consideration, and those that don't.  The
 // given versions MUST be sorted first by module path and then by semver.
-func buildVersionDetails(currentModulePath string, modInfos []*internal.ModuleInfo, linkify func(v *internal.ModuleInfo) string) *VersionsDetails {
+func buildVersionDetails(ctx context.Context, currentModulePath string, modInfos []*internal.ModuleInfo, linkify func(v *internal.ModuleInfo) string) *VersionsDetails {
 	// lists organizes versions by VersionListKey. Note that major version isn't
 	// sufficient as a key: there are packages contained in the same major
 	// version of different modules, for example github.com/hashicorp/vault/api,
@@ -165,6 +173,12 @@ func buildVersionDetails(currentModulePath string, modInfos []*internal.ModuleIn
 			CommitTime: absoluteTime(mi.CommitTime),
 			Version:    linkVersion(mi.Version, mi.ModulePath),
 		}
+		if experiment.IsActive(ctx, internal.ExperimentRetractions) {
+			key.Deprecated = mi.Deprecated
+			key.DeprecationComment = mi.DeprecationComment
+			vs.Retracted = mi.Retracted
+			vs.RetractionRationale = mi.RetractionRationale
+		}
 		if _, ok := lists[key]; !ok {
 			seenLists = append(seenLists, key)
 		}

internal/testing/integration/integration_test.go

@@ -80,6 +80,8 @@ func TestEndToEndProcessing(t *testing.T) {
 		{"example.com/single@v1.0.0/pkg", "hello"},
 		{"example.com/deprecated", "UnitHeader-deprecatedBanner"},
 		{"example.com/retractions@v1.1.0", "UnitHeader-retractedBanner"},
+		{"example.com/deprecated?tab=versions", "Deprecated: use something else"},
+		{"example.com/retractions?tab=versions", "Retracted: bad"},
 	} {
 		t.Run(strings.ReplaceAll(test.url, "/", "_"), func(t *testing.T) {
 			wantKeys = append(wantKeys, "/"+test.url)