Add support for a content dir set per language

A sample config:

```toml
defaultContentLanguage = "en"
defaultContentLanguageInSubdir = true

[Languages]
[Languages.en]
weight = 10
title = "In English"
languageName = "English"
contentDir = "content/english"

[Languages.nn]
weight = 20
title = "På Norsk"
languageName = "Norsk"
contentDir = "content/norwegian"
```

The value of `contentDir` can be any valid path, even absolute path references. The only restriction is that the content dirs cannot overlap.

The content files will be assigned a language by

1. The placement: `content/norwegian/post/my-post.md` will be read as Norwegian content.
2. The filename: `content/english/post/my-post.nn.md` will be read as Norwegian even if it lives in the English content folder.

The content directories will be merged into a big virtual filesystem with one simple rule: The most specific language file will win.
This means that if both `content/norwegian/post/my-post.md` and `content/english/post/my-post.nn.md` exists, they will be considered duplicates and the version inside `content/norwegian` will win.

Note that translations will be automatically assigned by Hugo by the content file's relative placement, so `content/norwegian/post/my-post.md` will be a translation of `content/english/post/my-post.md`.

If this does not work for you, you can connect the translations together by setting a `translationKey` in the content files' front matter.

Fixes #4523
Fixes #4552
Fixes #4553

1 files changed, 33 insertions, 12 deletions

diff --git a/resource/testhelpers_test.go b/resource/testhelpers_test.go
index a9015ab2c..9b50633bd 100644
--- a/resource/testhelpers_test.go
+++ b/resource/testhelpers_test.go
@@ -4,6 +4,7 @@ import (
 	"path/filepath"
 	"testing"
 
+	"fmt"
 	"image"
 	"io"
 	"io/ioutil"
@@ -27,7 +28,8 @@ func newTestResourceSpec(assert *require.Assertions) *Spec {
 func newTestResourceSpecForBaseURL(assert *require.Assertions, baseURL string) *Spec {
 	cfg := viper.New()
 	cfg.Set("baseURL", baseURL)
-	cfg.Set("resourceDir", "/res")
+	cfg.Set("resourceDir", "resources")
+	cfg.Set("contentDir", "content")
 
 	imagingCfg := map[string]interface{}{
 		"resampleFilter": "linear",
@@ -60,9 +62,8 @@ func newTestResourceOsFs(assert *require.Assertions) *Spec {
 		workDir = "/private" + workDir
 	}
 
-	contentDir := "base"
 	cfg.Set("workingDir", workDir)
-	cfg.Set("contentDir", contentDir)
+	cfg.Set("contentDir", filepath.Join(workDir, "content"))
 	cfg.Set("resourceDir", filepath.Join(workDir, "res"))
 
 	fs := hugofs.NewFrom(hugofs.Os, cfg)
@@ -97,10 +98,8 @@ func fetchResourceForSpec(spec *Spec, assert *require.Assertions, name string) R
 	src, err := os.Open(filepath.FromSlash("testdata/" + name))
 	assert.NoError(err)
 
-	workingDir := spec.Cfg.GetString("workingDir")
-	f := filepath.Join(workingDir, name)
-
-	out, err := spec.Fs.Source.Create(f)
+	assert.NoError(spec.BaseFs.ContentFs.MkdirAll(filepath.Dir(name), 0755))
+	out, err := spec.BaseFs.ContentFs.Create(name)
 	assert.NoError(err)
 	_, err = io.Copy(out, src)
 	out.Close()
@@ -111,14 +110,17 @@ func fetchResourceForSpec(spec *Spec, assert *require.Assertions, name string) R
 		return path.Join("/a", s)
 	}
 
-	r, err := spec.NewResourceFromFilename(factory, "/public", f, name)
+	r, err := spec.NewResourceFromFilename(factory, name, name)
 	assert.NoError(err)
 
 	return r
 }
 
-func assertImageFile(assert *require.Assertions, fs *hugofs.Fs, filename string, width, height int) {
-	f, err := fs.Source.Open(filename)
+func assertImageFile(assert *require.Assertions, fs afero.Fs, filename string, width, height int) {
+	f, err := fs.Open(filename)
+	if err != nil {
+		printFs(fs, "", os.Stdout)
+	}
 	assert.NoError(err)
 	defer f.Close()
 
@@ -129,8 +131,8 @@ func assertImageFile(assert *require.Assertions, fs *hugofs.Fs, filename string,
 	assert.Equal(height, config.Height)
 }
 
-func assertFileCache(assert *require.Assertions, fs *hugofs.Fs, filename string, width, height int) {
-	assertImageFile(assert, fs, filepath.Join("/res/_gen/images", filename), width, height)
+func assertFileCache(assert *require.Assertions, fs afero.Fs, filename string, width, height int) {
+	assertImageFile(assert, fs, filepath.Join("_gen/images", filename), width, height)
 }
 
 func writeSource(t testing.TB, fs *hugofs.Fs, filename, content string) {
@@ -142,3 +144,22 @@ func writeToFs(t testing.TB, fs afero.Fs, filename, content string) {
 		t.Fatalf("Failed to write file: %s", err)
 	}
 }
+
+func printFs(fs afero.Fs, path string, w io.Writer) {
+	if fs == nil {
+		return
+	}
+	afero.Walk(fs, path, func(path string, info os.FileInfo, err error) error {
+		if info != nil && !info.IsDir() {
+			s := path
+			if lang, ok := info.(hugofs.LanguageAnnouncer); ok {
+				s = s + "\t" + lang.Lang()
+			}
+			if fp, ok := info.(hugofs.FilePather); ok {
+				s += "\tFilename: " + fp.Filename() + "\tBase: " + fp.BaseDir()
+			}
+			fmt.Fprintln(w, "    ", s)
+		}
+		return nil
+	})
+}