Add Hugo Modules

This commit implements Hugo Modules.

This is a broad subject, but some keywords include:

* A new `module` configuration section where you can import almost anything. You can configure both your own file mounts nd the file mounts of the modules you import. This is the new recommended way of configuring what you earlier put in `configDir`, `staticDir` etc. And it also allows you to mount folders in non-Hugo-projects, e.g. the `SCSS` folder in the Bootstrap GitHub project.
* A module consists of a set of mounts to the standard 7 component types in Hugo: `static`, `content`, `layouts`, `data`, `assets`, `i18n`, and `archetypes`. Yes, Theme Components can now include content, which should be very useful, especially in bigger multilingual projects.
* Modules not in your local file cache will be downloaded automatically and even "hot replaced" while the server is running.
* Hugo Modules supports and encourages semver versioned modules, and uses the minimal version selection algorithm to resolve versions.
* A new set of CLI commands are provided to manage all of this: `hugo mod init`,  `hugo mod get`,  `hugo mod graph`,  `hugo mod tidy`, and  `hugo mod vendor`.

All of the above is backed by Go Modules.

Fixes #5973
Fixes #5996
Fixes #6010
Fixes #5911
Fixes #5940
Fixes #6074
Fixes #6082
Fixes #6092

1 files changed, 188 insertions, 11 deletions

diff --git a/hugofs/rootmapping_fs_test.go b/hugofs/rootmapping_fs_test.go
index e6a0301c9..3845ad5e6 100644
--- a/hugofs/rootmapping_fs_test.go
+++ b/hugofs/rootmapping_fs_test.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The Hugo Authors. All rights reserved.
+// 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.
@@ -19,24 +19,115 @@ import (
 	"path/filepath"
 	"testing"
 
+	"github.com/spf13/viper"
+
+	"github.com/gohugoio/hugo/htesting"
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/require"
 )
 
-func TestRootMappingFsRealName(t *testing.T) {
+func TestLanguageRootMapping(t *testing.T) {
 	assert := require.New(t)
-	fs := afero.NewMemMapFs()
+	v := viper.New()
+	v.Set("contentDir", "content")
+
+	fs := NewBaseFileDecorator(afero.NewMemMapFs())
+
+	assert.NoError(afero.WriteFile(fs, filepath.Join("content/sv/svdir", "main.txt"), []byte("main sv"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/mysvblogcontent", "sv-f.txt"), []byte("some sv blog content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/myenblogcontent", "en-f.txt"), []byte("some en blog content in a"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/myotherenblogcontent", "en-f2.txt"), []byte("some en content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/mysvdocs", "sv-docs.txt"), []byte("some sv docs content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/b/myenblogcontent", "en-b-f.txt"), []byte("some en content"), 0755))
+
+	rfs, err := NewRootMappingFs(fs,
+		RootMapping{
+			From: "content/blog",             // Virtual path, first element is one of content, static, layouts etc.
+			To:   "themes/a/mysvblogcontent", // Real path
+			Meta: FileMeta{"lang": "sv"},
+		},
+		RootMapping{
+			From: "content/blog",
+			To:   "themes/a/myenblogcontent",
+			Meta: FileMeta{"lang": "en"},
+		},
+		RootMapping{
+			From: "content/blog",
+			To:   "content/sv",
+			Meta: FileMeta{"lang": "sv"},
+		},
+		RootMapping{
+			From: "content/blog",
+			To:   "themes/a/myotherenblogcontent",
+			Meta: FileMeta{"lang": "en"},
+		},
+		RootMapping{
+			From: "content/docs",
+			To:   "themes/a/mysvdocs",
+			Meta: FileMeta{"lang": "sv"},
+		},
+	)
 
-	rfs, err := NewRootMappingFs(fs, "f1", "f1t", "f2", "f2t")
 	assert.NoError(err)
 
-	assert.Equal(filepath.FromSlash("f1t/foo/file.txt"), rfs.realName(filepath.Join("f1", "foo", "file.txt")))
+	collected, err := collectFilenames(rfs, "content", "content")
+	assert.NoError(err)
+	assert.Equal([]string{"blog/en-f.txt", "blog/en-f2.txt", "blog/sv-f.txt", "blog/svdir/main.txt", "docs/sv-docs.txt"}, collected)
+
+	bfs := afero.NewBasePathFs(rfs, "content")
+	collected, err = collectFilenames(bfs, "", "")
+	assert.NoError(err)
+	assert.Equal([]string{"blog/en-f.txt", "blog/en-f2.txt", "blog/sv-f.txt", "blog/svdir/main.txt", "docs/sv-docs.txt"}, collected)
+
+	dirs, err := rfs.Dirs(filepath.FromSlash("content/blog"))
+	assert.NoError(err)
+
+	assert.Equal(4, len(dirs))
+
+	getDirnames := func(name string, rfs *RootMappingFs) []string {
+		filename := filepath.FromSlash(name)
+		f, err := rfs.Open(filename)
+		assert.NoError(err)
+		names, err := f.Readdirnames(-1)
+
+		f.Close()
+		assert.NoError(err)
+
+		info, err := rfs.Stat(filename)
+		assert.NoError(err)
+		f2, err := info.(FileMetaInfo).Meta().Open()
+		assert.NoError(err)
+		names2, err := f2.Readdirnames(-1)
+		assert.NoError(err)
+		assert.Equal(names, names2)
+		f2.Close()
+
+		return names
+	}
+
+	rfsEn := rfs.Filter(func(rm RootMapping) bool {
+		return rm.Meta.Lang() == "en"
+	})
+
+	assert.Equal([]string{"en-f.txt", "en-f2.txt"}, getDirnames("content/blog", rfsEn))
+
+	rfsSv := rfs.Filter(func(rm RootMapping) bool {
+		return rm.Meta.Lang() == "sv"
+	})
+
+	assert.Equal([]string{"sv-f.txt", "svdir"}, getDirnames("content/blog", rfsSv))
+
+	// Make sure we have not messed with the original
+	assert.Equal([]string{"sv-f.txt", "en-f.txt", "svdir", "en-f2.txt"}, getDirnames("content/blog", rfs))
+
+	assert.Equal([]string{"blog", "docs"}, getDirnames("content", rfsSv))
+	assert.Equal([]string{"blog", "docs"}, getDirnames("content", rfs))
 
 }
 
 func TestRootMappingFsDirnames(t *testing.T) {
 	assert := require.New(t)
-	fs := afero.NewMemMapFs()
+	fs := NewBaseFileDecorator(afero.NewMemMapFs())
 
 	testfile := "myfile.txt"
 	assert.NoError(fs.Mkdir("f1t", 0755))
@@ -44,13 +135,14 @@ func TestRootMappingFsDirnames(t *testing.T) {
 	assert.NoError(fs.Mkdir("f3t", 0755))
 	assert.NoError(afero.WriteFile(fs, filepath.Join("f2t", testfile), []byte("some content"), 0755))
 
-	rfs, err := NewRootMappingFs(fs, "bf1", "f1t", "cf2", "f2t", "af3", "f3t")
+	rfs, err := NewRootMappingFsFromFromTo(fs, "static/bf1", "f1t", "static/cf2", "f2t", "static/af3", "f3t")
 	assert.NoError(err)
 
-	fif, err := rfs.Stat(filepath.Join("cf2", testfile))
+	fif, err := rfs.Stat(filepath.Join("static/cf2", testfile))
 	assert.NoError(err)
 	assert.Equal("myfile.txt", fif.Name())
-	assert.Equal(filepath.FromSlash("f2t/myfile.txt"), fif.(RealFilenameInfo).RealFilename())
+	fifm := fif.(FileMetaInfo).Meta()
+	assert.Equal(filepath.FromSlash("f2t/myfile.txt"), fifm.Filename())
 
 	root, err := rfs.Open(filepathSeparator)
 	assert.NoError(err)
@@ -61,6 +153,91 @@ func TestRootMappingFsDirnames(t *testing.T) {
 
 }
 
+func TestRootMappingFsFilename(t *testing.T) {
+	assert := require.New(t)
+	workDir, clean, err := htesting.CreateTempDir(Os, "hugo-root-filename")
+	assert.NoError(err)
+	defer clean()
+	fs := NewBaseFileDecorator(Os)
+
+	testfilename := filepath.Join(workDir, "f1t/foo/file.txt")
+
+	assert.NoError(fs.MkdirAll(filepath.Join(workDir, "f1t/foo"), 0777))
+	assert.NoError(afero.WriteFile(fs, testfilename, []byte("content"), 0666))
+
+	rfs, err := NewRootMappingFsFromFromTo(fs, "static/f1", filepath.Join(workDir, "f1t"), "static/f2", filepath.Join(workDir, "f2t"))
+	assert.NoError(err)
+
+	fi, err := rfs.Stat(filepath.FromSlash("static/f1/foo/file.txt"))
+	assert.NoError(err)
+	fim := fi.(FileMetaInfo)
+	assert.Equal(testfilename, fim.Meta().Filename())
+	_, err = rfs.Stat(filepath.FromSlash("static/f1"))
+	assert.NoError(err)
+}
+
+func TestRootMappingFsMount(t *testing.T) {
+	assert := require.New(t)
+	fs := NewBaseFileDecorator(afero.NewMemMapFs())
+
+	testfile := "test.txt"
+
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/mynoblogcontent", testfile), []byte("some no content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/myenblogcontent", testfile), []byte("some en content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/mysvblogcontent", testfile), []byte("some sv content"), 0755))
+	assert.NoError(afero.WriteFile(fs, filepath.Join("themes/a/mysvblogcontent", "other.txt"), []byte("some sv content"), 0755))
+
+	bfs := afero.NewBasePathFs(fs, "themes/a").(*afero.BasePathFs)
+	rm := []RootMapping{
+		RootMapping{From: "content/blog",
+			To:   "mynoblogcontent",
+			Meta: FileMeta{"lang": "no"},
+		},
+		RootMapping{From: "content/blog",
+			To:   "myenblogcontent",
+			Meta: FileMeta{"lang": "en"},
+		},
+		RootMapping{From: "content/blog",
+			To:   "mysvblogcontent",
+			Meta: FileMeta{"lang": "sv"},
+		},
+	}
+
+	rfs, err := NewRootMappingFs(bfs, rm...)
+	assert.NoError(err)
+
+	blog, err := rfs.Stat(filepath.FromSlash("content/blog"))
+	assert.NoError(err)
+	blogm := blog.(FileMetaInfo).Meta()
+	assert.Equal("sv", blogm.Lang()) // Last match
+
+	f, err := blogm.Open()
+	assert.NoError(err)
+	defer f.Close()
+	dirs1, err := f.Readdirnames(-1)
+	assert.NoError(err)
+	// Union with duplicate dir names filtered.
+	assert.Equal([]string{"test.txt", "test.txt", "other.txt", "test.txt"}, dirs1)
+
+	files, err := afero.ReadDir(rfs, filepath.FromSlash("content/blog"))
+	assert.NoError(err)
+	assert.Equal(4, len(files))
+
+	testfilefi := files[1]
+	assert.Equal(testfile, testfilefi.Name())
+
+	testfilem := testfilefi.(FileMetaInfo).Meta()
+	assert.Equal(filepath.FromSlash("themes/a/mynoblogcontent/test.txt"), testfilem.Filename())
+
+	tf, err := testfilem.Open()
+	assert.NoError(err)
+	defer tf.Close()
+	c, err := ioutil.ReadAll(tf)
+	assert.NoError(err)
+	assert.Equal("some no content", string(c))
+
+}
+
 func TestRootMappingFsOs(t *testing.T) {
 	assert := require.New(t)
 	fs := afero.NewOsFs()
@@ -77,10 +254,10 @@ func TestRootMappingFsOs(t *testing.T) {
 	assert.NoError(fs.Mkdir(filepath.Join(d, "f3t"), 0755))
 	assert.NoError(afero.WriteFile(fs, filepath.Join(d, "f2t", testfile), []byte("some content"), 0755))
 
-	rfs, err := NewRootMappingFs(fs, "bf1", filepath.Join(d, "f1t"), "cf2", filepath.Join(d, "f2t"), "af3", filepath.Join(d, "f3t"))
+	rfs, err := NewRootMappingFsFromFromTo(fs, "static/bf1", filepath.Join(d, "f1t"), "static/cf2", filepath.Join(d, "f2t"), "static/af3", filepath.Join(d, "f3t"))
 	assert.NoError(err)
 
-	fif, err := rfs.Stat(filepath.Join("cf2", testfile))
+	fif, err := rfs.Stat(filepath.Join("static/cf2", testfile))
 	assert.NoError(err)
 	assert.Equal("myfile.txt", fif.Name())