integrity: Add support for sha384

Fixes #5815

resources/resource_transformers/integrity/integrity_test.go

@@ -0,0 +1,48 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package integrity
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestHashFromAlgo(t *testing.T) {
+
+	for _, algo := range []struct {
+		name string
+		bits int
+	}{
+		{"md5", 128},
+		{"sha256", 256},
+		{"sha384", 384},
+		{"sha512", 512},
+		{"shaman", -1},
+	} {
+
+		t.Run(algo.name, func(t *testing.T) {
+			assert := require.New(t)
+			h, err := newHash(algo.name)
+			if algo.bits > 0 {
+				assert.NoError(err)
+				assert.Equal(algo.bits/8, h.Size())
+			} else {
+				assert.Error(err)
+				assert.Contains(err.Error(), "use either md5, sha256, sha384 or sha512")
+			}
+
+		})
+	}
+}