internal/postgres: add WithLicenses to GetUnit

GetUnit now supports the WithLicenses fieldset, which fetches license
contents for the unit.

For golang/go#39629

Change-Id: Ic51baf1d36e75c7ad05c59d232f400a756fb7a94
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/252318
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>

3 files changed, 26 insertions, 9 deletions

diff --git a/internal/postgres/insert_module_test.go b/internal/postgres/insert_module_test.go
index acaeaee4..fd74d67e 100644
--- a/internal/postgres/insert_module_test.go
+++ b/internal/postgres/insert_module_test.go
@@ -109,28 +109,28 @@ func checkModule(ctx context.Context, t *testing.T, want *internal.Module) {
 		}
 	}
 
-	for _, dir := range want.Units {
-		got, err := testDB.GetUnit(ctx, &dir.UnitMeta, internal.AllFields)
+	for _, wantu := range want.Units {
+		got, err := testDB.GetUnit(ctx, &wantu.UnitMeta, internal.AllFields)
 		if err != nil {
 			t.Fatal(err)
 		}
 		// TODO(golang/go#38513): remove once we start displaying
 		// READMEs for directories instead of the top-level module.
-		dir.Readme = &internal.Readme{
+		wantu.Readme = &internal.Readme{
 			Filepath: sample.ReadmeFilePath,
 			Contents: sample.ReadmeContents,
 		}
-		if dir.Package != nil {
-			dir.Name = dir.Package.Name
+		wantu.LicenseContents = sample.Licenses
+		if wantu.Package != nil {
+			wantu.Name = wantu.Package.Name
 		}
-		wantd := dir
 		opts := cmp.Options{
 			cmpopts.IgnoreFields(internal.LegacyModuleInfo{}, "LegacyReadmeFilePath"),
 			cmpopts.IgnoreFields(internal.LegacyModuleInfo{}, "LegacyReadmeContents"),
 			cmpopts.IgnoreFields(licenses.Metadata{}, "Coverage"),
 			cmp.AllowUnexported(source.Info{}, safehtml.HTML{}),
 		}
-		if diff := cmp.Diff(wantd, got, opts); diff != "" {
+		if diff := cmp.Diff(wantu, got, opts); diff != "" {
 			t.Errorf("mismatch (-want +got):\n%s", diff)
 		}
 	}
diff --git a/internal/postgres/unit.go b/internal/postgres/unit.go
index a8070541..59871efd 100644
--- a/internal/postgres/unit.go
+++ b/internal/postgres/unit.go
@@ -121,6 +121,13 @@ func (db *DB) GetUnit(ctx context.Context, um *internal.UnitMeta, fields interna
 			u.Imports = imports
 		}
 	}
+	if fields&internal.WithLicenses != 0 {
+		lics, err := db.getLicenses(ctx, u.Path, u.ModulePath, pathID)
+		if err != nil {
+			return nil, err
+		}
+		u.LicenseContents = lics
+	}
 	if fields == internal.AllFields {
 		if u.Name != "" {
 			if u.Package == nil {
diff --git a/internal/postgres/unit_test.go b/internal/postgres/unit_test.go
index a5154c8e..d2ffe817 100644
--- a/internal/postgres/unit_test.go
+++ b/internal/postgres/unit_test.go
@@ -363,6 +363,9 @@ func TestGetUnitFieldSet(t *testing.T) {
 		if fields&internal.WithImports != 0 {
 			u.Imports = sample.Imports
 		}
+		if fields&internal.WithLicenses == 0 {
+			u.LicenseContents = nil
+		}
 		if u.Package != nil {
 			u.Package.Name = u.Name
 		}
@@ -386,6 +389,12 @@ func TestGetUnitFieldSet(t *testing.T) {
 				nil, nil),
 		},
 		{
+			name:   "WithLicenses",
+			fields: internal.WithLicenses,
+			want: unit("a.com/m/dir/p", "a.com/m", "v1.2.3",
+				nil, nil),
+		},
+		{
 			name:   "WithReadme",
 			fields: internal.WithReadme,
 			want: unit("a.com/m/dir/p", "a.com/m", "v1.2.3",
@@ -431,8 +440,9 @@ func unit(path, modulePath, version string, readme *internal.Readme, pkg *intern
 			IsRedistributable: true,
 			Licenses:          sample.LicenseMetadata,
 		},
-		Readme:  readme,
-		Package: pkg,
+		LicenseContents: sample.Licenses,
+		Readme:          readme,
+		Package:         pkg,
 	}
 	if pkg != nil {
 		u.Name = pkg.Name