1 files changed, 174 insertions, 0 deletions
diff --git a/modules/module.go b/modules/module.go
new file mode 100644
index 000000000..a5f707635
--- /dev/null
+++ b/modules/module.go
@@ -0,0 +1,174 @@
+// 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 modules provides a client that can be used to manage Hugo Components,
+// what's referred to as Hugo Modules. Hugo Modules is built on top of Go Modules,
+// but also supports vendoring and components stored directly in the themes dir.
+package modules
+
+import (
+	"github.com/gohugoio/hugo/config"
+)
+
+var _ Module = (*moduleAdapter)(nil)
+
+type Module interface {
+
+	// Optional config read from the configFilename above.
+	Cfg() config.Provider
+
+	// The decoded module config and mounts.
+	Config() Config
+
+	// Optional configuration filename (e.g. "/themes/mytheme/config.json").
+	// This will be added to the special configuration watch list when in
+	// server mode.
+	ConfigFilename() string
+
+	// Directory holding files for this module.
+	Dir() string
+
+	// This module is disabled.
+	Disabled() bool
+
+	// Returns whether this is a Go Module.
+	IsGoMod() bool
+
+	// Any directory remappings.
+	Mounts() []Mount
+
+	// In the dependency tree, this is the first module that defines this module
+	// as a dependency.
+	Owner() Module
+
+	// Returns the path to this module.
+	// This will either be the module path, e.g. "github.com/gohugoio/myshortcodes",
+	// or the path below your /theme folder, e.g. "mytheme".
+	Path() string
+
+	// Replaced by this module.
+	Replace() Module
+
+	// Returns whether Dir points below the _vendor dir.
+	Vendor() bool
+
+	// The module version.
+	Version() string
+
+	// Whether this module's dir is a watch candidate.
+	Watch() bool
+}
+
+type Modules []Module
+
+type moduleAdapter struct {
+	path       string
+	dir        string
+	version    string
+	vendor     bool
+	disabled   bool
+	projectMod bool
+	owner      Module
+
+	mounts []Mount
+
+	configFilename string
+	cfg            config.Provider
+	config         Config
+
+	// Set if a Go module.
+	gomod *goModule
+}
+
+func (m *moduleAdapter) Cfg() config.Provider {
+	return m.cfg
+}
+
+func (m *moduleAdapter) Config() Config {
+	return m.config
+}
+
+func (m *moduleAdapter) ConfigFilename() string {
+	return m.configFilename
+}
+
+func (m *moduleAdapter) Dir() string {
+	// This may point to the _vendor dir.
+	if !m.IsGoMod() || m.dir != "" {
+		return m.dir
+	}
+	return m.gomod.Dir
+}
+
+func (m *moduleAdapter) Disabled() bool {
+	return m.disabled
+}
+
+func (m *moduleAdapter) IsGoMod() bool {
+	return m.gomod != nil
+}
+
+func (m *moduleAdapter) Mounts() []Mount {
+	return m.mounts
+}
+
+func (m *moduleAdapter) Owner() Module {
+	return m.owner
+}
+
+func (m *moduleAdapter) Path() string {
+	if !m.IsGoMod() || m.path != "" {
+		return m.path
+	}
+	return m.gomod.Path
+}
+
+func (m *moduleAdapter) Replace() Module {
+	if m.IsGoMod() && !m.Vendor() && m.gomod.Replace != nil {
+		return &moduleAdapter{
+			gomod: m.gomod.Replace,
+			owner: m.owner,
+		}
+	}
+	return nil
+}
+
+func (m *moduleAdapter) Vendor() bool {
+	return m.vendor
+}
+
+func (m *moduleAdapter) Version() string {
+	if !m.IsGoMod() || m.version != "" {
+		return m.version
+	}
+	return m.gomod.Version
+}
+
+func (m *moduleAdapter) Watch() bool {
+	if m.Owner() == nil {
+		// Main project
+		return true
+	}
+
+	if !m.IsGoMod() {
+		// Module inside /themes
+		return true
+	}
+
+	if m.Replace() != nil {
+		// Version is not set when replaced by a local folder.
+		return m.Replace().Version() == ""
+	}
+
+	return false
+}