media: Allow multiple file suffixes per media type

Before this commit, `Suffix` on `MediaType` was used both to set a custom file suffix and as a way to augment the mediatype definition (what you see after the "+", e.g. "image/svg+xml").

This had its limitations. For one, it was only possible with one file extension per MIME type.

Now you can specify multiple file suffixes using "suffixes", but you need to specify the full MIME type
identifier:

[mediaTypes]
[mediaTypes."image/svg+xml"]
suffixes = ["svg", "abc ]

In most cases, it will be enough to just change:

[mediaTypes]
[mediaTypes."my/custom-mediatype"]
suffix = "txt"

To:

[mediaTypes]
[mediaTypes."my/custom-mediatype"]
suffixes = ["txt"]

Hugo will still respect values set in "suffix" if no value for "suffixes" is provided, but this will be removed in a future release.

Note that you can still get the Media Type's suffix from a template: {{ $mediaType.Suffix }}. But this will now map to the MIME type filename.

Fixes #4920

4 files changed, 5 insertions, 6 deletions

diff --git a/resource/bundler/bundler.go b/resource/bundler/bundler.go
index 2f3981485..a86b39efa 100644
--- a/resource/bundler/bundler.go
+++ b/resource/bundler/bundler.go
@@ -70,7 +70,7 @@ func (c *Client) Concat(targetPath string, resources []resource.Resource) (resou
 		// The given set of resources must be of the same Media Type.
 		// We may improve on that in the future, but then we need to know more.
 		for i, r := range resources {
-			if i > 0 && r.MediaType() != resolvedm {
+			if i > 0 && r.MediaType().Type() != resolvedm.Type() {
 				return nil, errors.New("resources in Concat must be of the same Media Type")
 			}
 			resolvedm = r.MediaType()
diff --git a/resource/minifiers/minify.go b/resource/minifiers/minify.go
index 609b9a694..604ac6f8c 100644
--- a/resource/minifiers/minify.go
+++ b/resource/minifiers/minify.go
@@ -45,7 +45,7 @@ func New(rs *resource.Spec) *Client {
 	addMinifierFunc(m, mt, "text/html", "html", html.Minify)
 	addMinifierFunc(m, mt, "application/javascript", "js", js.Minify)
 	addMinifierFunc(m, mt, "application/json", "json", json.Minify)
-	addMinifierFunc(m, mt, "image/svg", "xml", svg.Minify)
+	addMinifierFunc(m, mt, "image/svg+xml", "svg", svg.Minify)
 	addMinifierFunc(m, mt, "application/xml", "xml", xml.Minify)
 	addMinifierFunc(m, mt, "application/rss", "xml", xml.Minify)
 
diff --git a/resource/resource.go b/resource/resource.go
index f0989e51e..a7a9cb878 100644
--- a/resource/resource.go
+++ b/resource/resource.go
@@ -416,16 +416,15 @@ func (r *Spec) newResource(sourceFs afero.Fs, fd ResourceSourceDescriptor) (Reso
 	mimeType, found := r.MediaTypes.GetFirstBySuffix(strings.TrimPrefix(ext, "."))
 	// TODO(bep) we need to handle these ambigous types better, but in this context
 	// we most likely want the application/xml type.
-	if mimeType.Suffix == "xml" && mimeType.SubType == "rss" {
+	if mimeType.Suffix() == "xml" && mimeType.SubType == "rss" {
 		mimeType, found = r.MediaTypes.GetByType("application/xml")
 	}
 
 	if !found {
 		mimeStr := mime.TypeByExtension(ext)
 		if mimeStr != "" {
-			mimeType, _ = media.FromString(mimeStr)
+			mimeType, _ = media.FromStringAndExt(mimeStr, ext)
 		}
-
 	}
 
 	gr := r.newGenericResourceWithBase(
diff --git a/resource/resource_test.go b/resource/resource_test.go
index 659994c36..e699e6f3f 100644
--- a/resource/resource_test.go
+++ b/resource/resource_test.go
@@ -97,7 +97,7 @@ func TestNewResourceFromFilenameSubPathInBaseURL(t *testing.T) {
 
 }
 
-var pngType, _ = media.FromString("image/png")
+var pngType, _ = media.FromStringAndExt("image/png", "png")
 
 func TestResourcesByType(t *testing.T) {
 	assert := require.New(t)