Create a struct with all of Hugo's config options

Primary motivation is documentation, but it will also hopefully simplify the code.

Also,

* Lower case the default output format names; this is in line with the custom ones (map keys) and how
it's treated all the places. This avoids doing `stringds.EqualFold` everywhere.

Closes gohugoio#10896
Closes gohugoio#10620

.gitignore

@@ -1,2 +1,3 @@
 
-*.test
+*.test
+imports.*

cache/docs.go

@@ -0,0 +1,2 @@
+// Package cache contains the differenct cache implementations.
+package cache

cache/filecache/filecache.go

@@ -35,7 +35,7 @@ import (
 var ErrFatal = errors.New("fatal filecache error")
 
 const (
-	filecacheRootDirname = "filecache"
+	FilecacheRootDirname = "filecache"
 )
 
 // Cache caches a set of files in a directory. This is usually a file on
@@ -301,7 +301,7 @@ func (c *Cache) isExpired(modTime time.Time) bool {
 }
 
 // For testing
-func (c *Cache) getString(id string) string {
+func (c *Cache) GetString(id string) string {
 	id = cleanID(id)
 
 	c.nlocker.Lock(id)
@@ -328,38 +328,24 @@ func (f Caches) Get(name string) *Cache {
 // NewCaches creates a new set of file caches from the given
 // configuration.
 func NewCaches(p *helpers.PathSpec) (Caches, error) {
-	var dcfg Configs
-	if c, ok := p.Cfg.Get("filecacheConfigs").(Configs); ok {
-		dcfg = c
-	} else {
-		var err error
-		dcfg, err = DecodeConfig(p.Fs.Source, p.Cfg)
-		if err != nil {
-			return nil, err
-		}
-	}
-
+	dcfg := p.Cfg.GetConfigSection("caches").(Configs)
 	fs := p.Fs.Source
 
 	m := make(Caches)
 	for k, v := range dcfg {
 		var cfs afero.Fs
 
-		if v.isResourceDir {
+		if v.IsResourceDir {
 			cfs = p.BaseFs.ResourcesCache
 		} else {
 			cfs = fs
 		}
 
 		if cfs == nil {
-			// TODO(bep) we still have some places that do not initialize the
-			// full dependencies of a site, e.g. the import Jekyll command.
-			// That command does not need these caches, so let us just continue
-			// for now.
-			continue
+			panic("nil fs")
 		}
 
-		baseDir := v.Dir
+		baseDir := v.DirCompiled
 
 		if err := cfs.MkdirAll(baseDir, 0777); err != nil && !os.IsExist(err) {
 			return nil, err
@@ -368,7 +354,7 @@ func NewCaches(p *helpers.PathSpec) (Caches, error) {
 		bfs := afero.NewBasePathFs(cfs, baseDir)
 
 		var pruneAllRootDir string
-		if k == cacheKeyModules {
+		if k == CacheKeyModules {
 			pruneAllRootDir = "pkg"
 		}
 

cache/filecache/filecache_config.go

@@ -11,6 +11,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Package filecache provides a file based cache for Hugo.
 package filecache
 
 import (
@@ -21,110 +22,111 @@ import (
 	"time"
 
 	"github.com/gohugoio/hugo/common/maps"
-
 	"github.com/gohugoio/hugo/config"
 
-	"github.com/gohugoio/hugo/helpers"
-
 	"errors"
 
 	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/afero"
 )
 
 const (
-	cachesConfigKey = "caches"
-
 	resourcesGenDir = ":resourceDir/_gen"
 	cacheDirProject = ":cacheDir/:project"
 )
 
-var defaultCacheConfig = Config{
+var defaultCacheConfig = FileCacheConfig{
 	MaxAge: -1, // Never expire
 	Dir:    cacheDirProject,
 }
 
 const (
-	cacheKeyGetJSON     = "getjson"
-	cacheKeyGetCSV      = "getcsv"
-	cacheKeyImages      = "images"
-	cacheKeyAssets      = "assets"
-	cacheKeyModules     = "modules"
-	cacheKeyGetResource = "getresource"
+	CacheKeyGetJSON     = "getjson"
+	CacheKeyGetCSV      = "getcsv"
+	CacheKeyImages      = "images"
+	CacheKeyAssets      = "assets"
+	CacheKeyModules     = "modules"
+	CacheKeyGetResource = "getresource"
 )
 
-type Configs map[string]Config
+type Configs map[string]FileCacheConfig
 
+// For internal use.
 func (c Configs) CacheDirModules() string {
-	return c[cacheKeyModules].Dir
+	return c[CacheKeyModules].DirCompiled
 }
 
 var defaultCacheConfigs = Configs{
-	cacheKeyModules: {
+	CacheKeyModules: {
 		MaxAge: -1,
 		Dir:    ":cacheDir/modules",
 	},
-	cacheKeyGetJSON: defaultCacheConfig,
-	cacheKeyGetCSV:  defaultCacheConfig,
-	cacheKeyImages: {
+	CacheKeyGetJSON: defaultCacheConfig,
+	CacheKeyGetCSV:  defaultCacheConfig,
+	CacheKeyImages: {
 		MaxAge: -1,
 		Dir:    resourcesGenDir,
 	},
-	cacheKeyAssets: {
+	CacheKeyAssets: {
 		MaxAge: -1,
 		Dir:    resourcesGenDir,
 	},
-	cacheKeyGetResource: Config{
+	CacheKeyGetResource: FileCacheConfig{
 		MaxAge: -1, // Never expire
 		Dir:    cacheDirProject,
 	},
 }
 
-type Config struct {
+type FileCacheConfig struct {
 	// Max age of cache entries in this cache. Any items older than this will
 	// be removed and not returned from the cache.
-	// a negative value means forever, 0 means cache is disabled.
+	// A negative value means forever, 0 means cache is disabled.
+	// Hugo is leninent with what types it accepts here, but we recommend using
+	// a duration string, a sequence of  decimal numbers, each with optional fraction and a unit suffix,
+	// such as "300ms", "1.5h" or "2h45m".
+	// Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
 	MaxAge time.Duration
 
 	// The directory where files are stored.
-	Dir string
+	Dir         string
+	DirCompiled string `json:"-"`
 
 	// Will resources/_gen will get its own composite filesystem that
 	// also checks any theme.
-	isResourceDir bool
+	IsResourceDir bool
 }
 
 // GetJSONCache gets the file cache for getJSON.
 func (f Caches) GetJSONCache() *Cache {
-	return f[cacheKeyGetJSON]
+	return f[CacheKeyGetJSON]
 }
 
 // GetCSVCache gets the file cache for getCSV.
 func (f Caches) GetCSVCache() *Cache {
-	return f[cacheKeyGetCSV]
+	return f[CacheKeyGetCSV]
 }
 
 // ImageCache gets the file cache for processed images.
 func (f Caches) ImageCache() *Cache {
-	return f[cacheKeyImages]
+	return f[CacheKeyImages]
 }
 
 // ModulesCache gets the file cache for Hugo Modules.
 func (f Caches) ModulesCache() *Cache {
-	return f[cacheKeyModules]
+	return f[CacheKeyModules]
 }
 
 // AssetsCache gets the file cache for assets (processed resources, SCSS etc.).
 func (f Caches) AssetsCache() *Cache {
-	return f[cacheKeyAssets]
+	return f[CacheKeyAssets]
 }
 
 // GetResourceCache gets the file cache for remote resources.
 func (f Caches) GetResourceCache() *Cache {
-	return f[cacheKeyGetResource]
+	return f[CacheKeyGetResource]
 }
 
-func DecodeConfig(fs afero.Fs, cfg config.Provider) (Configs, error) {
+func DecodeConfig(fs afero.Fs, bcfg config.BaseConfig, m map[string]any) (Configs, error) {
 	c := make(Configs)
 	valid := make(map[string]bool)
 	// Add defaults
@@ -133,8 +135,6 @@ func DecodeConfig(fs afero.Fs, cfg config.Provider) (Configs, error) {
 		valid[k] = true
 	}
 
-	m := cfg.GetStringMap(cachesConfigKey)
-
 	_, isOsFs := fs.(*afero.OsFs)
 
 	for k, v := range m {
@@ -170,22 +170,19 @@ func DecodeConfig(fs afero.Fs, cfg config.Provider) (Configs, error) {
 		c[name] = cc
 	}
 
-	// This is a very old flag in Hugo, but we need to respect it.
-	disabled := cfg.GetBool("ignoreCache")
-
 	for k, v := range c {
 		dir := filepath.ToSlash(filepath.Clean(v.Dir))
 		hadSlash := strings.HasPrefix(dir, "/")
 		parts := strings.Split(dir, "/")
 
 		for i, part := range parts {
 			if strings.HasPrefix(part, ":") {
-				resolved, isResource, err := resolveDirPlaceholder(fs, cfg, part)
+				resolved, isResource, err := resolveDirPlaceholder(fs, bcfg, part)
 				if err != nil {
 					return c, err
 				}
 				if isResource {
-					v.isResourceDir = true
+					v.IsResourceDir = true
 				}
 				parts[i] = resolved
 			}
@@ -195,33 +192,29 @@ func DecodeConfig(fs afero.Fs, cfg config.Provider) (Configs, error) {
 		if hadSlash {
 			dir = "/" + dir
 		}
-		v.Dir = filepath.Clean(filepath.FromSlash(dir))
+		v.DirCompiled = filepath.Clean(filepath.FromSlash(dir))
 
-		if !v.isResourceDir {
-			if isOsFs && !filepath.IsAbs(v.Dir) {
-				return c, fmt.Errorf("%q must resolve to an absolute directory", v.Dir)
+		if !v.IsResourceDir {
+			if isOsFs && !filepath.IsAbs(v.DirCompiled) {
+				return c, fmt.Errorf("%q must resolve to an absolute directory", v.DirCompiled)
 			}
 
 			// Avoid cache in root, e.g. / (Unix) or c:\ (Windows)
-			if len(strings.TrimPrefix(v.Dir, filepath.VolumeName(v.Dir))) == 1 {
-				return c, fmt.Errorf("%q is a root folder and not allowed as cache dir", v.Dir)
+			if len(strings.TrimPrefix(v.DirCompiled, filepath.VolumeName(v.DirCompiled))) == 1 {
+				return c, fmt.Errorf("%q is a root folder and not allowed as cache dir", v.DirCompiled)
 			}
 		}
 
-		if !strings.HasPrefix(v.Dir, "_gen") {
+		if !strings.HasPrefix(v.DirCompiled, "_gen") {
 			// We do cache eviction (file removes) and since the user can set
 			// his/hers own cache directory, we really want to make sure
 			// we do not delete any files that do not belong to this cache.
 			// We do add the cache name as the root, but this is an extra safe
 			// guard. We skip the files inside /resources/_gen/ because
 			// that would be breaking.
-			v.Dir = filepath.Join(v.Dir, filecacheRootDirname, k)
+			v.DirCompiled = filepath.Join(v.DirCompiled, FilecacheRootDirname, k)
 		} else {
-			v.Dir = filepath.Join(v.Dir, k)
-		}
-
-		if disabled {
-			v.MaxAge = 0
+			v.DirCompiled = filepath.Join(v.DirCompiled, k)
 		}
 
 		c[k] = v
@@ -231,17 +224,15 @@ func DecodeConfig(fs afero.Fs, cfg config.Provider) (Configs, error) {
 }
 
 // Resolves :resourceDir => /myproject/resources etc., :cacheDir => ...
-func resolveDirPlaceholder(fs afero.Fs, cfg config.Provider, placeholder string) (cacheDir string, isResource bool, err error) {
-	workingDir := cfg.GetString("workingDir")
+func resolveDirPlaceholder(fs afero.Fs, bcfg config.BaseConfig, placeholder string) (cacheDir string, isResource bool, err error) {
 
 	switch strings.ToLower(placeholder) {
 	case ":resourcedir":
 		return "", true, nil
 	case ":cachedir":
-		d, err := helpers.GetCacheDir(fs, cfg)
-		return d, false, err
+		return bcfg.CacheDir, false, nil
 	case ":project":
-		return filepath.Base(workingDir), false, nil
+		return filepath.Base(bcfg.WorkingDir), false, nil
 	}
 
 	return "", false, fmt.Errorf("%q is not a valid placeholder (valid values are :cacheDir or :resourceDir)", placeholder)