Allow slices in the image Filter funcs, not just varargs

[ci skip]

See #6255

resources/image.go

@@ -28,6 +28,8 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/disintegration/gift"
+
 	"github.com/gohugoio/hugo/cache/filecache"
 	"github.com/gohugoio/hugo/resources/images/exif"
 
@@ -37,7 +39,6 @@ import (
 
 	_errors "github.com/pkg/errors"
 
-	"github.com/disintegration/gift"
 	"github.com/gohugoio/hugo/helpers"
 	"github.com/gohugoio/hugo/resources/images"
 
@@ -209,12 +210,19 @@ func (i *imageResource) Fill(spec string) (resource.Image, error) {
 	})
 }
 
-func (i *imageResource) Filter(filters ...gift.Filter) (resource.Image, error) {
+func (i *imageResource) Filter(filters ...interface{}) (resource.Image, error) {
 	conf := i.Proc.GetDefaultImageConfig("filter")
-	conf.Key = internal.HashString(filters)
+
+	var gfilters []gift.Filter
+
+	for _, f := range filters {
+		gfilters = append(gfilters, images.ToFilters(f)...)
+	}
+
+	conf.Key = internal.HashString(gfilters)
 
 	return i.doWithImageConfig(conf, func(src image.Image) (image.Image, error) {
-		return i.Proc.Filter(src, filters...)
+		return i.Proc.Filter(src, gfilters...)
 	})
 }
 
@@ -331,9 +339,6 @@ func (i *imageResource) getImageMetaCacheTargetPath() string {
 
 func (i *imageResource) relTargetPathFromConfig(conf images.ImageConfig) dirFile {
 	p1, p2 := helpers.FileAndExt(i.getResourcePaths().relTargetDirFile.file)
-	if conf.Action == "trace" {
-		p2 = ".svg"
-	}
 
 	h, _ := i.hash()
 	idStr := fmt.Sprintf("_hu%s_%d", h, i.size())

resources/image_test.go

@@ -512,7 +512,7 @@ func TestImageOperationsGolden(t *testing.T) {
 			c.Assert(rel, qt.Not(qt.Equals), "")
 		}
 
-		resized, err = resized.Filter(filters[0:4]...)
+		resized, err = resized.Filter(filters[0:4])
 		c.Assert(err, qt.IsNil)
 		rel := resized.RelPermalink()
 		c.Log("filter all", rel)

resources/images/filters_test.go

@@ -0,0 +1,34 @@
+// 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 images
+
+import (
+	"testing"
+
+	"github.com/gohugoio/hugo/resources/internal"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestFilterHash(t *testing.T) {
+	c := qt.New(t)
+
+	f := &Filters{}
+
+	c.Assert(internal.HashString(f.Grayscale()), qt.Equals, internal.HashString(f.Grayscale()))
+	c.Assert(internal.HashString(f.Grayscale()), qt.Not(qt.Equals), internal.HashString(f.Invert()))
+	c.Assert(internal.HashString(f.Gamma(32)), qt.Not(qt.Equals), internal.HashString(f.Gamma(33)))
+	c.Assert(internal.HashString(f.Gamma(32)), qt.Equals, internal.HashString(f.Gamma(32)))
+
+}

resources/images/image.go

@@ -14,6 +14,7 @@
 package images
 
 import (
+	"fmt"
 	"image"
 	"image/color"
 	"image/gif"
@@ -259,3 +260,20 @@ func imageConfigFromImage(img image.Image) image.Config {
 	b := img.Bounds()
 	return image.Config{Width: b.Max.X, Height: b.Max.Y}
 }
+
+func ToFilters(in interface{}) []gift.Filter {
+	switch v := in.(type) {
+	case []gift.Filter:
+		return v
+	case []filter:
+		vv := make([]gift.Filter, len(v))
+		for i, f := range v {
+			vv[i] = f
+		}
+		return vv
+	case gift.Filter:
+		return []gift.Filter{v}
+	default:
+		panic(fmt.Sprintf("%T is not an image filter", in))
+	}
+}

resources/resource/resourcetypes.go

@@ -14,7 +14,6 @@
 package resource
 
 import (
-	"github.com/disintegration/gift"
 	"github.com/gohugoio/hugo/langs"
 	"github.com/gohugoio/hugo/media"
 	"github.com/gohugoio/hugo/resources/images/exif"
@@ -49,7 +48,7 @@ type ImageOps interface {
 	Fill(spec string) (Image, error)
 	Fit(spec string) (Image, error)
 	Resize(spec string) (Image, error)
-	Filter(filters ...gift.Filter) (Image, error)
+	Filter(filters ...interface{}) (Image, error)
 	Exif() (*exif.Exif, error)
 }
 

resources/transform.go

@@ -21,7 +21,6 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/disintegration/gift"
 	"github.com/gohugoio/hugo/resources/images/exif"
 	"github.com/spf13/afero"
 
@@ -174,7 +173,7 @@ func (r *resourceAdapter) Fit(spec string) (resource.Image, error) {
 	return r.getImageOps().Fit(spec)
 }
 
-func (r *resourceAdapter) Filter(filters ...gift.Filter) (resource.Image, error) {
+func (r *resourceAdapter) Filter(filters ...interface{}) (resource.Image, error) {
 	return r.getImageOps().Filter(filters...)
 }