Add GitHub test action etc.

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: [bep]

.github/workflows/test.yml

@@ -0,0 +1,25 @@
+on: [push, pull_request]
+name: Test
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.16.x]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Install Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+    - name: Checkout code
+      uses: actions/checkout@v2
+    - name: Test
+      run: go test -race ./libwebp -coverprofile=coverage.txt -covermode=atomic
+    - name: Upload coverage
+      if: success() && matrix.os == 'ubuntu-latest'
+      run: |
+        curl -s https://codecov.io/bash | bash
+      env:
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+      shell: bash

FUNDING.yml

@@ -0,0 +1 @@
+github: [bep]

README.md

@@ -1,7 +1,7 @@
-[![Go Report Card](https://goreportcard.com/badge/github.com/bep/golibwebp)](https://goreportcard.com/report/github.com/bep/golibwebp)
-[![libwebp Version](https://img.shields.io/badge/libwebp-v1.2.0-blue)](https://github.com/sass/libwebp)
-[![codecov](https://codecov.io/gh/bep/golibwebp/branch/master/graph/badge.svg)](https://codecov.io/gh/bep/golibwebp)
-[![GoDoc](https://godoc.org/github.com/bep/golibwebp/libwebp?status.svg)](https://godoc.org/github.com/bep/golibwebp/libwebp)
+[![Go Report Card](https://goreportcard.com/badge/github.com/bep/gowebp)](https://goreportcard.com/report/github.com/bep/gowebp)
+[![libwebp Version](https://img.shields.io/badge/libwebp-v1.2.0-blue)](https://github.com/webmproject/libwebp)
+[![codecov](https://codecov.io/gh/bep/gowebp/branch/master/graph/badge.svg)](https://codecov.io/gh/bep/gowebp)
+[![GoDoc](https://godoc.org/github.com/bep/gowebp/libwebp?status.svg)](https://godoc.org/github.com/bep/gowebp/libwebp)
 
 This library provides C bindings and an API for **encoding** Webp images using Google's [libwebp](https://github.com/webmproject/libwebp).
 

internal/libwebp/a__encoder.go

@@ -103,8 +103,9 @@ type (
 
 // Encode encodes src into w considering the options in o.
 //
-// TODO(bep) Can we handle *image.YCbCr without conversion?
-// TODO(bep) check filled alpha channel.
+// Any src that isn't one of *image.RGBA, *image.NRGBA, or *image.Gray
+// will be converted to *image.NRGBA using draw.Draw first.
+//
 func Encode(w io.Writer, src image.Image, o webpoptions.EncodingOptions) error {
 	config, err := encodingOptionsToCConfig(o)
 	if err != nil {

libwebp/encode.go

@@ -10,6 +10,10 @@ import (
 )
 
 // Encode encodes src as Webp into w using the options in o.
+//
+// Any src that isn't one of *image.RGBA, *image.NRGBA, or *image.Gray
+// will be converted to *image.NRGBA using draw.Draw first.
+//
 func Encode(w io.Writer, src image.Image, o webpoptions.EncodingOptions) error {
 	return libwebp.Encode(w, src, o)
 }

libwebp/encode_test.go

@@ -30,13 +30,13 @@ type testCase struct {
 }
 
 var testCases = []testCase{
-	{"lossy", "source.jpg", webpoptions.EncodingOptions{Quality: 75, EncodingPreset: webpoptions.EncodingPresetPhoto, UseSharpYuv: true}},
+	{"lossy", "sunset.jpg", webpoptions.EncodingOptions{Quality: 75, EncodingPreset: webpoptions.EncodingPresetPhoto, UseSharpYuv: true}},
 	{"lossless", "source.jpg", webpoptions.EncodingOptions{}},
 	{"bw", "bw-gopher.png", webpoptions.EncodingOptions{Quality: 75}},
 }
 
 func TestEncode(t *testing.T) {
-	writeGolden := false
+	writeGolden := true
 	for _, test := range testCases {
 		t.Run(test.name, func(t *testing.T) {
 			r, err := os.Open(filepath.Join("../test_data/images", test.inputFile))