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 #10896
Closes #10620

1 files changed, 27 insertions, 70 deletions

diff --git a/config/defaultConfigProvider.go b/config/defaultConfigProvider.go
index 822f421fa..e8a08e281 100644
--- a/config/defaultConfigProvider.go
+++ b/config/defaultConfigProvider.go
@@ -19,6 +19,8 @@ import (
 	"strings"
 	"sync"
 
+	xmaps "golang.org/x/exp/maps"
+
 	"github.com/spf13/cast"
 
 	"github.com/gohugoio/hugo/common/maps"
@@ -75,11 +77,6 @@ func NewFrom(params maps.Params) Provider {
 	}
 }
 
-// NewWithTestDefaults is used in tests only.
-func NewWithTestDefaults() Provider {
-	return SetBaseTestDefaults(New())
-}
-
 // defaultConfigProvider is a Provider backed by a map where all keys are lower case.
 // All methods are thread safe.
 type defaultConfigProvider struct {
@@ -160,9 +157,9 @@ func (c *defaultConfigProvider) Set(k string, v any) {
 	k = strings.ToLower(k)
 
 	if k == "" {
-		if p, ok := maps.ToParamsAndPrepare(v); ok {
+		if p, err := maps.ToParamsAndPrepare(v); err == nil {
 			// Set the values directly in root.
-			c.root.Set(p)
+			maps.SetParams(c.root, p)
 		} else {
 			c.root[k] = v
 		}
@@ -184,7 +181,7 @@ func (c *defaultConfigProvider) Set(k string, v any) {
 	if existing, found := m[key]; found {
 		if p1, ok := existing.(maps.Params); ok {
 			if p2, ok := v.(maps.Params); ok {
-				p1.Set(p2)
+				maps.SetParams(p1, p2)
 				return
 			}
 		}
@@ -208,12 +205,6 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 	defer c.mu.Unlock()
 	k = strings.ToLower(k)
 
-	const (
-		languagesKey = "languages"
-		paramsKey    = "params"
-		menusKey     = "menus"
-	)
-
 	if k == "" {
 		rs, f := c.root.GetMergeStrategy()
 		if f && rs == maps.ParamsMergeStrategyNone {
@@ -222,7 +213,7 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 			return
 		}
 
-		if p, ok := maps.ToParamsAndPrepare(v); ok {
+		if p, err := maps.ToParamsAndPrepare(v); err == nil {
 			// As there may be keys in p not in root, we need to handle
 			// those as a special case.
 			var keysToDelete []string
@@ -230,49 +221,14 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 				if pp, ok := vv.(maps.Params); ok {
 					if pppi, ok := c.root[kk]; ok {
 						ppp := pppi.(maps.Params)
-						if kk == languagesKey {
-							// Languages is currently a special case.
-							// We may have languages with menus or params in the
-							// right map that is not present in the left map.
-							// With the default merge strategy those items will not
-							// be passed over.
-							var hasParams, hasMenus bool
-							for _, rv := range pp {
-								if lkp, ok := rv.(maps.Params); ok {
-									_, hasMenus = lkp[menusKey]
-									_, hasParams = lkp[paramsKey]
-								}
-							}
-
-							if hasMenus || hasParams {
-								for _, lv := range ppp {
-									if lkp, ok := lv.(maps.Params); ok {
-										if hasMenus {
-											if _, ok := lkp[menusKey]; !ok {
-												p := maps.Params{}
-												p.SetDefaultMergeStrategy(maps.ParamsMergeStrategyShallow)
-												lkp[menusKey] = p
-											}
-										}
-										if hasParams {
-											if _, ok := lkp[paramsKey]; !ok {
-												p := maps.Params{}
-												p.SetDefaultMergeStrategy(maps.ParamsMergeStrategyShallow)
-												lkp[paramsKey] = p
-											}
-										}
-									}
-								}
-							}
-						}
-						ppp.Merge(pp)
+						maps.MergeParamsWithStrategy("", ppp, pp)
 					} else {
 						// We need to use the default merge strategy for
 						// this key.
 						np := make(maps.Params)
-						strategy := c.determineMergeStrategy(KeyParams{Key: "", Params: c.root}, KeyParams{Key: kk, Params: np})
-						np.SetDefaultMergeStrategy(strategy)
-						np.Merge(pp)
+						strategy := c.determineMergeStrategy(maps.KeyParams{Key: "", Params: c.root}, maps.KeyParams{Key: kk, Params: np})
+						np.SetMergeStrategy(strategy)
+						maps.MergeParamsWithStrategy("", np, pp)
 						c.root[kk] = np
 						if np.IsZero() {
 							// Just keep it until merge is done.
@@ -282,7 +238,7 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 				}
 			}
 			// Merge the rest.
-			c.root.MergeRoot(p)
+			maps.MergeParams(c.root, p)
 			for _, k := range keysToDelete {
 				delete(c.root, k)
 			}
@@ -307,7 +263,7 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 	if existing, found := m[key]; found {
 		if p1, ok := existing.(maps.Params); ok {
 			if p2, ok := v.(maps.Params); ok {
-				p1.Merge(p2)
+				maps.MergeParamsWithStrategy("", p1, p2)
 			}
 		}
 	} else {
@@ -315,9 +271,15 @@ func (c *defaultConfigProvider) Merge(k string, v any) {
 	}
 }
 
-func (c *defaultConfigProvider) WalkParams(walkFn func(params ...KeyParams) bool) {
-	var walk func(params ...KeyParams)
-	walk = func(params ...KeyParams) {
+func (c *defaultConfigProvider) Keys() []string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return xmaps.Keys(c.root)
+}
+
+func (c *defaultConfigProvider) WalkParams(walkFn func(params ...maps.KeyParams) bool) {
+	var walk func(params ...maps.KeyParams)
+	walk = func(params ...maps.KeyParams) {
 		if walkFn(params...) {
 			return
 		}
@@ -325,17 +287,17 @@ func (c *defaultConfigProvider) WalkParams(walkFn func(params ...KeyParams) bool
 		i := len(params)
 		for k, v := range p1.Params {
 			if p2, ok := v.(maps.Params); ok {
-				paramsplus1 := make([]KeyParams, i+1)
+				paramsplus1 := make([]maps.KeyParams, i+1)
 				copy(paramsplus1, params)
-				paramsplus1[i] = KeyParams{Key: k, Params: p2}
+				paramsplus1[i] = maps.KeyParams{Key: k, Params: p2}
 				walk(paramsplus1...)
 			}
 		}
 	}
-	walk(KeyParams{Key: "", Params: c.root})
+	walk(maps.KeyParams{Key: "", Params: c.root})
 }
 
-func (c *defaultConfigProvider) determineMergeStrategy(params ...KeyParams) maps.ParamsMergeStrategy {
+func (c *defaultConfigProvider) determineMergeStrategy(params ...maps.KeyParams) maps.ParamsMergeStrategy {
 	if len(params) == 0 {
 		return maps.ParamsMergeStrategyNone
 	}
@@ -391,13 +353,8 @@ func (c *defaultConfigProvider) determineMergeStrategy(params ...KeyParams) maps
 	return strategy
 }
 
-type KeyParams struct {
-	Key    string
-	Params maps.Params
-}
-
 func (c *defaultConfigProvider) SetDefaultMergeStrategy() {
-	c.WalkParams(func(params ...KeyParams) bool {
+	c.WalkParams(func(params ...maps.KeyParams) bool {
 		if len(params) == 0 {
 			return false
 		}
@@ -409,7 +366,7 @@ func (c *defaultConfigProvider) SetDefaultMergeStrategy() {
 		}
 		strategy := c.determineMergeStrategy(params...)
 		if strategy != "" {
-			p.SetDefaultMergeStrategy(strategy)
+			p.SetMergeStrategy(strategy)
 		}
 		return false
 	})