Move the mount duplicate filter to the modules package

Also simplify the mount validation logic. There are plenty of ways a user can create mount configs that behaves oddly.

modules/client.go

@@ -66,7 +66,6 @@ const (
 // level imports to start out.
 func NewClient(cfg ClientConfig) *Client {
 	fs := cfg.Fs
-
 	n := filepath.Join(cfg.WorkingDir, goModFilename)
 	goModEnabled, _ := afero.Exists(fs, n)
 	var goModFilename string
@@ -97,9 +96,7 @@ func NewClient(cfg ClientConfig) *Client {
 
 	return &Client{
 		fs:                fs,
-		ignoreVendor:      cfg.IgnoreVendor,
-		workingDir:        cfg.WorkingDir,
-		themesDir:         cfg.ThemesDir,
+		ccfg:              cfg,
 		logger:            logger,
 		moduleConfig:      mcfg,
 		environ:           env,
@@ -111,14 +108,7 @@ type Client struct {
 	fs     afero.Fs
 	logger *loggers.Logger
 
-	// Ignore any _vendor directory.
-	ignoreVendor bool
-
-	// Absolute path to the project dir.
-	workingDir string
-
-	// Absolute path to the project's themes dir.
-	themesDir string
+	ccfg ClientConfig
 
 	// The top level module config
 	moduleConfig Config
@@ -194,7 +184,7 @@ func (c *Client) Tidy() error {
 // meaning that if the top-level module is vendored, that will be the full
 // set of dependencies.
 func (c *Client) Vendor() error {
-	vendorDir := filepath.Join(c.workingDir, vendord)
+	vendorDir := filepath.Join(c.ccfg.WorkingDir, vendord)
 	if err := c.rmVendorDir(vendorDir); err != nil {
 		return err
 	}
@@ -284,7 +274,7 @@ func (c *Client) Init(path string) error {
 		return errors.Wrap(err, "failed to init modules")
 	}
 
-	c.GoModulesFilename = filepath.Join(c.workingDir, goModFilename)
+	c.GoModulesFilename = filepath.Join(c.ccfg.WorkingDir, goModFilename)
 
 	return nil
 }
@@ -335,7 +325,7 @@ func (c *Client) rewriteGoMod(name string, isGoMod map[string]bool) error {
 		return err
 	}
 	if data != nil {
-		if err := afero.WriteFile(c.fs, filepath.Join(c.workingDir, name), data, 0666); err != nil {
+		if err := afero.WriteFile(c.fs, filepath.Join(c.ccfg.WorkingDir, name), data, 0666); err != nil {
 			return err
 		}
 	}
@@ -352,7 +342,7 @@ func (c *Client) rewriteGoModRewrite(name string, isGoMod map[string]bool) ([]by
 	modlineSplitter := getModlineSplitter(name == goModFilename)
 
 	b := &bytes.Buffer{}
-	f, err := c.fs.Open(filepath.Join(c.workingDir, name))
+	f, err := c.fs.Open(filepath.Join(c.ccfg.WorkingDir, name))
 	if err != nil {
 		if os.IsNotExist(err) {
 			// It's been deleted.
@@ -424,7 +414,7 @@ func (c *Client) runGo(
 	cmd := exec.CommandContext(ctx, "go", args...)
 
 	cmd.Env = c.environ
-	cmd.Dir = c.workingDir
+	cmd.Dir = c.ccfg.WorkingDir
 	cmd.Stdout = stdout
 	cmd.Stderr = io.MultiWriter(stderr, os.Stderr)
 
@@ -482,11 +472,22 @@ func (c *Client) tidy(mods Modules, goModOnly bool) error {
 
 // ClientConfig configures the module Client.
 type ClientConfig struct {
-	Fs           afero.Fs
-	Logger       *loggers.Logger
+	Fs     afero.Fs
+	Logger *loggers.Logger
+
+	// If set, it will be run before we do any duplicate checks for modules
+	// etc.
+	HookBeforeFinalize func(m *ModulesConfig) error
+
+	// Ignore any _vendor directory.
 	IgnoreVendor bool
-	WorkingDir   string
-	ThemesDir    string // Absolute directory path
+
+	// Absolute path to the project dir.
+	WorkingDir string
+
+	// Absolute path to the project's themes dir.
+	ThemesDir string
+
 	CacheDir     string // Module cache
 	ModuleConfig Config
 }

modules/collect.go

@@ -20,6 +20,8 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/gohugoio/hugo/common/loggers"
+
 	"github.com/spf13/cast"
 
 	"github.com/gohugoio/hugo/common/maps"
@@ -62,8 +64,25 @@ func CreateProjectModule(cfg config.Provider) (Module, error) {
 
 func (h *Client) Collect() (ModulesConfig, error) {
 	mc, coll := h.collect(true)
-	return mc, coll.err
+	if coll.err != nil {
+		return mc, coll.err
+	}
 
+	if err := (&mc).setActiveMods(h.logger); err != nil {
+		return mc, err
+	}
+
+	if h.ccfg.HookBeforeFinalize != nil {
+		if err := h.ccfg.HookBeforeFinalize(&mc); err != nil {
+			return mc, err
+		}
+	}
+
+	if err := (&mc).finalize(h.logger); err != nil {
+		return mc, err
+	}
+
+	return mc, nil
 }
 
 func (h *Client) collect(tidy bool) (ModulesConfig, *collector) {
@@ -83,20 +102,8 @@ func (h *Client) collect(tidy bool) (ModulesConfig, *collector) {
 		}
 	}
 
-	// TODO(bep) consider --ignoreVendor vs removing from go.mod
-	var activeMods Modules
-	for _, mod := range c.modules {
-		if !mod.Config().HugoVersion.IsValid() {
-			h.logger.WARN.Printf(`Module %q is not compatible with this Hugo version; run "hugo mod graph" for more information.`, mod.Path())
-		}
-		if !mod.Disabled() {
-			activeMods = append(activeMods, mod)
-		}
-	}
-
 	return ModulesConfig{
 		AllModules:        c.modules,
-		ActiveModules:     activeMods,
 		GoModulesFilename: c.GoModulesFilename,
 	}, c
 
@@ -113,6 +120,43 @@ type ModulesConfig struct {
 	GoModulesFilename string
 }
 
+func (m *ModulesConfig) setActiveMods(logger *loggers.Logger) error {
+	var activeMods Modules
+	for _, mod := range m.AllModules {
+		if !mod.Config().HugoVersion.IsValid() {
+			logger.WARN.Printf(`Module %q is not compatible with this Hugo version; run "hugo mod graph" for more information.`, mod.Path())
+		}
+		if !mod.Disabled() {
+			activeMods = append(activeMods, mod)
+		}
+	}
+
+	m.ActiveModules = activeMods
+
+	return nil
+}
+
+func (m *ModulesConfig) finalize(logger *loggers.Logger) error {
+	for _, mod := range m.AllModules {
+		m := mod.(*moduleAdapter)
+		m.mounts = filterUnwantedMounts(m.mounts)
+	}
+	return nil
+}
+
+func filterUnwantedMounts(mounts []Mount) []Mount {
+	// Remove duplicates
+	seen := make(map[Mount]bool)
+	tmp := mounts[:0]
+	for _, m := range mounts {
+		if !seen[m] {
+			tmp = append(tmp, m)
+		}
+		seen[m] = true
+	}
+	return tmp
+}
+
 type collected struct {
 	// Pick the first and prevent circular loops.
 	seen map[string]bool
@@ -177,7 +221,7 @@ func (c *collector) add(owner *moduleAdapter, moduleImport Import, disabled bool
 	modulePath := moduleImport.Path
 	var realOwner Module = owner
 
-	if !c.ignoreVendor {
+	if !c.ccfg.IgnoreVendor {
 		if err := c.collectModulesTXT(owner); err != nil {
 			return nil, err
 		}
@@ -223,10 +267,10 @@ func (c *collector) add(owner *moduleAdapter, moduleImport Import, disabled bool
 
 			// Fall back to /themes/<mymodule>
 			if moduleDir == "" {
-				moduleDir = filepath.Join(c.themesDir, modulePath)
+				moduleDir = filepath.Join(c.ccfg.ThemesDir, modulePath)
 
 				if found, _ := afero.Exists(c.fs, moduleDir); !found {
-					c.err = c.wrapModuleNotFound(errors.Errorf(`module %q not found; either add it as a Hugo Module or store it in %q.`, modulePath, c.themesDir))
+					c.err = c.wrapModuleNotFound(errors.Errorf(`module %q not found; either add it as a Hugo Module or store it in %q.`, modulePath, c.ccfg.ThemesDir))
 					return nil, nil
 				}
 			}
@@ -427,7 +471,7 @@ func (c *collector) collect() {
 		return
 	}
 
-	projectMod := createProjectModule(c.gomods.GetMain(), c.workingDir, c.moduleConfig)
+	projectMod := createProjectModule(c.gomods.GetMain(), c.ccfg.WorkingDir, c.moduleConfig)
 
 	if err := c.addAndRecurse(projectMod, false); err != nil {
 		c.err = err

modules/collect_test.go

@@ -36,3 +36,19 @@ func TestPathKey(t *testing.T) {
 	}
 
 }
+
+func TestFilterUnwantedMounts(t *testing.T) {
+
+	mounts := []Mount{
+		Mount{Source: "a", Target: "b", Lang: "en"},
+		Mount{Source: "a", Target: "b", Lang: "en"},
+		Mount{Source: "b", Target: "c", Lang: "en"},
+	}
+
+	filtered := filterUnwantedMounts(mounts)
+
+	assert := require.New(t)
+	assert.Len(filtered, 2)
+	assert.Equal([]Mount{Mount{Source: "a", Target: "b", Lang: "en"}, Mount{Source: "b", Target: "c", Lang: "en"}}, filtered)
+
+}

modules/config.go

@@ -15,7 +15,6 @@ package modules
 
 import (
 	"fmt"
-	"path"
 	"path/filepath"
 	"strings"
 
@@ -174,18 +173,7 @@ func ApplyProjectConfigDefaults(cfg config.Provider, mod Module) error {
 	// Prepend the mounts from configuration.
 	mounts = append(moda.mounts, mounts...)
 
-	// Remove duplicates
-	seen := make(map[string]bool)
-	tmp := mounts[:0]
-	for _, m := range mounts {
-		key := path.Join(m.Lang, m.Source, m.Target)
-		if !seen[key] {
-			tmp = append(tmp, m)
-		}
-		seen[key] = true
-	}
-
-	moda.mounts = tmp
+	moda.mounts = mounts
 
 	return nil
 }