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

13 files changed, 48 insertions, 100 deletions

diff --git a/tpl/collections/append_test.go b/tpl/collections/append_test.go
index 232781522..78cdcdd84 100644
--- a/tpl/collections/append_test.go
+++ b/tpl/collections/append_test.go
@@ -18,17 +18,13 @@ import (
 	"testing"
 
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/langs"
 )
 
 // Also see tests in common/collection.
 func TestAppend(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		start    any
diff --git a/tpl/collections/apply_test.go b/tpl/collections/apply_test.go
index 2c7783fd9..aa39923b7 100644
--- a/tpl/collections/apply_test.go
+++ b/tpl/collections/apply_test.go
@@ -21,10 +21,9 @@ import (
 	"testing"
 
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/langs"
+	"github.com/gohugoio/hugo/config/testconfig"
 	"github.com/gohugoio/hugo/output"
+	"github.com/gohugoio/hugo/output/layouts"
 	"github.com/gohugoio/hugo/tpl"
 )
 
@@ -46,7 +45,7 @@ func (templateFinder) LookupVariants(name string) []tpl.Template {
 	return nil
 }
 
-func (templateFinder) LookupLayout(d output.LayoutDescriptor, f output.Format) (tpl.Template, bool, error) {
+func (templateFinder) LookupLayout(d layouts.LayoutDescriptor, f output.Format) (tpl.Template, bool, error) {
 	return nil, false, nil
 }
 
@@ -69,8 +68,10 @@ func (templateFinder) GetFunc(name string) (reflect.Value, bool) {
 func TestApply(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	d := &deps.Deps{Language: langs.NewDefaultLanguage(config.New())}
-	d.SetTmpl(new(templateFinder))
+	d := testconfig.GetTestDeps(nil, nil)
+	d.SetTempl(&tpl.TemplateHandlers{
+		Tmpl: new(templateFinder),
+	})
 	ns := New(d)
 
 	strings := []any{"a\n", "b\n"}
diff --git a/tpl/collections/collections.go b/tpl/collections/collections.go
index 994d5f1b4..35a87394a 100644
--- a/tpl/collections/collections.go
+++ b/tpl/collections/collections.go
@@ -43,11 +43,11 @@ func init() {
 
 // New returns a new instance of the collections-namespaced template functions.
 func New(deps *deps.Deps) *Namespace {
-	if deps.Language == nil {
+	language := deps.Conf.Language()
+	if language == nil {
 		panic("language must be set")
 	}
-
-	loc := langs.GetLocation(deps.Language)
+	loc := langs.GetLocation(language)
 
 	return &Namespace{
 		loc:      loc,
diff --git a/tpl/collections/collections_test.go b/tpl/collections/collections_test.go
index fd78da6d4..86192c480 100644
--- a/tpl/collections/collections_test.go
+++ b/tpl/collections/collections_test.go
@@ -23,15 +23,9 @@ import (
 	"time"
 
 	"github.com/gohugoio/hugo/common/maps"
+	"github.com/gohugoio/hugo/config/testconfig"
 
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/common/loggers"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/helpers"
-	"github.com/gohugoio/hugo/hugofs"
-	"github.com/gohugoio/hugo/langs"
-	"github.com/spf13/afero"
 )
 
 type tstNoStringer struct{}
@@ -40,7 +34,7 @@ func TestAfter(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		index  any
@@ -97,7 +91,7 @@ func (g *tstGrouper2) Group(key any, items any) (any, error) {
 func TestGroup(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		key    any
@@ -133,9 +127,7 @@ func TestDelimit(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{
-		Language: langs.NewDefaultLanguage(config.New()),
-	})
+	ns := newNs()
 
 	for i, test := range []struct {
 		seq       any
@@ -187,7 +179,7 @@ func TestDelimit(t *testing.T) {
 func TestDictionary(t *testing.T) {
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		values []any
@@ -226,7 +218,7 @@ func TestDictionary(t *testing.T) {
 func TestReverse(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	s := []string{"a", "b", "c"}
 	reversed, err := ns.Reverse(s)
@@ -245,7 +237,7 @@ func TestEchoParam(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		a      any
@@ -277,7 +269,7 @@ func TestFirst(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		limit  any
@@ -314,8 +306,7 @@ func TestFirst(t *testing.T) {
 func TestIn(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		l1     any
@@ -391,7 +382,7 @@ func TestIntersect(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		l1, l2 any
@@ -481,7 +472,7 @@ func TestIntersect(t *testing.T) {
 func TestIsSet(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := newTestNs()
+	ns := newNs()
 
 	for i, test := range []struct {
 		a      any
@@ -518,7 +509,7 @@ func TestLast(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		limit  any
@@ -557,7 +548,7 @@ func TestLast(t *testing.T) {
 func TestQuerify(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		params []any
@@ -591,7 +582,7 @@ func TestQuerify(t *testing.T) {
 }
 
 func BenchmarkQuerify(b *testing.B) {
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 	params := []any{"a", "b", "c", "d", "f", " &"}
 
 	b.ResetTimer()
@@ -604,7 +595,7 @@ func BenchmarkQuerify(b *testing.B) {
 }
 
 func BenchmarkQuerifySlice(b *testing.B) {
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 	params := []string{"a", "b", "c", "d", "f", " &"}
 
 	b.ResetTimer()
@@ -619,7 +610,7 @@ func BenchmarkQuerifySlice(b *testing.B) {
 func TestSeq(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		args   []any
@@ -663,7 +654,7 @@ func TestSeq(t *testing.T) {
 func TestShuffle(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		seq     any
@@ -703,7 +694,7 @@ func TestShuffle(t *testing.T) {
 func TestShuffleRandomising(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	// Note that this test can fail with false negative result if the shuffle
 	// of the sequence happens to be the same as the original sequence. However
@@ -734,7 +725,7 @@ func TestShuffleRandomising(t *testing.T) {
 func TestSlice(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		args     []any
@@ -758,7 +749,7 @@ func TestUnion(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	for i, test := range []struct {
 		l1     any
@@ -847,7 +838,7 @@ func TestUnion(t *testing.T) {
 func TestUniq(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 	for i, test := range []struct {
 		l      any
 		expect any
@@ -971,22 +962,6 @@ func ToTstXIs(slice any) []TstXI {
 	return tis
 }
 
-func newDeps(cfg config.Provider) *deps.Deps {
-	l := langs.NewLanguage("en", cfg)
-	l.Set("i18nDir", "i18n")
-	cs, err := helpers.NewContentSpec(l, loggers.NewErrorLogger(), afero.NewMemMapFs(), nil)
-	if err != nil {
-		panic(err)
-	}
-	return &deps.Deps{
-		Language:    l,
-		Cfg:         cfg,
-		Fs:          hugofs.NewMem(l),
-		ContentSpec: cs,
-		Log:         loggers.NewErrorLogger(),
-	}
-}
-
-func newTestNs() *Namespace {
-	return New(newDeps(config.NewWithTestDefaults()))
+func newNs() *Namespace {
+	return New(testconfig.GetTestDeps(nil, nil))
 }
diff --git a/tpl/collections/complement_test.go b/tpl/collections/complement_test.go
index 6c13ab5c4..761a2451c 100644
--- a/tpl/collections/complement_test.go
+++ b/tpl/collections/complement_test.go
@@ -17,10 +17,6 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/langs"
-
 	qt "github.com/frankban/quicktest"
 )
 
@@ -36,7 +32,7 @@ func TestComplement(t *testing.T) {
 
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	s1 := []TstX{{A: "a"}, {A: "b"}, {A: "d"}, {A: "e"}}
 	s2 := []TstX{{A: "b"}, {A: "e"}}
diff --git a/tpl/collections/index.go b/tpl/collections/index.go
index e4362fdc3..df932f7c6 100644
--- a/tpl/collections/index.go
+++ b/tpl/collections/index.go
@@ -64,7 +64,7 @@ func (ns *Namespace) doIndex(item any, args ...any) (any, error) {
 
 	lowerm, ok := item.(maps.Params)
 	if ok {
-		return lowerm.Get(cast.ToStringSlice(indices)...), nil
+		return lowerm.GetNested(cast.ToStringSlice(indices)...), nil
 	}
 
 	for _, i := range indices {
diff --git a/tpl/collections/index_test.go b/tpl/collections/index_test.go
index 7c917c443..0c5a58756 100644
--- a/tpl/collections/index_test.go
+++ b/tpl/collections/index_test.go
@@ -18,17 +18,14 @@ import (
 	"testing"
 
 	"github.com/gohugoio/hugo/common/maps"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/langs"
 
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/deps"
 )
 
 func TestIndex(t *testing.T) {
 	t.Parallel()
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	var (
 		emptyInterface any
diff --git a/tpl/collections/merge_test.go b/tpl/collections/merge_test.go
index 4dbc30741..7809152d4 100644
--- a/tpl/collections/merge_test.go
+++ b/tpl/collections/merge_test.go
@@ -19,9 +19,6 @@ import (
 	"testing"
 
 	"github.com/gohugoio/hugo/common/maps"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/langs"
 	"github.com/gohugoio/hugo/parser"
 	"github.com/gohugoio/hugo/parser/metadecoders"
 
@@ -29,7 +26,7 @@ import (
 )
 
 func TestMerge(t *testing.T) {
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	simpleMap := map[string]any{"a": 1, "b": 2}
 
@@ -164,7 +161,7 @@ func TestMerge(t *testing.T) {
 
 func TestMergeDataFormats(t *testing.T) {
 	c := qt.New(t)
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	toml1 := `
 V1 = "v1_1"
diff --git a/tpl/collections/sort.go b/tpl/collections/sort.go
index 9a1928b00..83029b310 100644
--- a/tpl/collections/sort.go
+++ b/tpl/collections/sort.go
@@ -46,7 +46,7 @@ func (ns *Namespace) Sort(l any, args ...any) (any, error) {
 		return nil, errors.New("can't sort " + reflect.ValueOf(l).Type().String())
 	}
 
-	collator := langs.GetCollator(ns.deps.Language)
+	collator := langs.GetCollator(ns.deps.Conf.Language())
 
 	// Create a list of pairs that will be used to do the sort
 	p := pairList{Collator: collator, sortComp: ns.sortComp, SortAsc: true, SliceType: sliceType}
@@ -87,7 +87,7 @@ func (ns *Namespace) Sort(l any, args ...any) (any, error) {
 					}
 					// Special handling of lower cased maps.
 					if params, ok := v.Interface().(maps.Params); ok {
-						v = reflect.ValueOf(params.Get(path[i+1:]...))
+						v = reflect.ValueOf(params.GetNested(path[i+1:]...))
 						break
 					}
 				}
@@ -117,7 +117,7 @@ func (ns *Namespace) Sort(l any, args ...any) (any, error) {
 					}
 					// Special handling of lower cased maps.
 					if params, ok := v.Interface().(maps.Params); ok {
-						v = reflect.ValueOf(params.Get(path[i+1:]...))
+						v = reflect.ValueOf(params.GetNested(path[i+1:]...))
 						break
 					}
 				}
diff --git a/tpl/collections/sort_test.go b/tpl/collections/sort_test.go
index a4adccf51..da9c75d04 100644
--- a/tpl/collections/sort_test.go
+++ b/tpl/collections/sort_test.go
@@ -19,10 +19,6 @@ import (
 	"testing"
 
 	"github.com/gohugoio/hugo/common/maps"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/langs"
-
-	"github.com/gohugoio/hugo/deps"
 )
 
 type stringsSlice []string
@@ -30,9 +26,7 @@ type stringsSlice []string
 func TestSort(t *testing.T) {
 	t.Parallel()
 
-	ns := New(&deps.Deps{
-		Language: langs.NewDefaultLanguage(config.New()),
-	})
+	ns := newNs()
 
 	type ts struct {
 		MyInt    int
diff --git a/tpl/collections/symdiff_test.go b/tpl/collections/symdiff_test.go
index e5494d5a0..548f91b6c 100644
--- a/tpl/collections/symdiff_test.go
+++ b/tpl/collections/symdiff_test.go
@@ -17,10 +17,6 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/deps"
-	"github.com/gohugoio/hugo/langs"
-
 	qt "github.com/frankban/quicktest"
 )
 
@@ -29,7 +25,7 @@ func TestSymDiff(t *testing.T) {
 
 	c := qt.New(t)
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	s1 := []TstX{{A: "a"}, {A: "b"}}
 	s2 := []TstX{{A: "a"}, {A: "e"}}
diff --git a/tpl/collections/where.go b/tpl/collections/where.go
index df29baf13..b20c290fa 100644
--- a/tpl/collections/where.go
+++ b/tpl/collections/where.go
@@ -380,7 +380,7 @@ func (ns *Namespace) checkWhereArray(seqv, kv, mv reflect.Value, path []string,
 
 		if kv.Kind() == reflect.String {
 			if params, ok := rvv.Interface().(maps.Params); ok {
-				vvv = reflect.ValueOf(params.Get(path...))
+				vvv = reflect.ValueOf(params.GetNested(path...))
 			} else {
 				vvv = rvv
 				for i, elemName := range path {
@@ -394,7 +394,7 @@ func (ns *Namespace) checkWhereArray(seqv, kv, mv reflect.Value, path []string,
 					if i < len(path)-1 && vvv.IsValid() {
 						if params, ok := vvv.Interface().(maps.Params); ok {
 							// The current path element is the map itself, .Params.
-							vvv = reflect.ValueOf(params.Get(path[i+1:]...))
+							vvv = reflect.ValueOf(params.GetNested(path[i+1:]...))
 							break
 						}
 					}
diff --git a/tpl/collections/where_test.go b/tpl/collections/where_test.go
index 9a65de3d5..e5ae85e88 100644
--- a/tpl/collections/where_test.go
+++ b/tpl/collections/where_test.go
@@ -22,16 +22,12 @@ import (
 	"time"
 
 	"github.com/gohugoio/hugo/common/maps"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/langs"
-
-	"github.com/gohugoio/hugo/deps"
 )
 
 func TestWhere(t *testing.T) {
 	t.Parallel()
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	type Mid struct {
 		Tst TstX
@@ -685,7 +681,7 @@ func TestWhere(t *testing.T) {
 func TestCheckCondition(t *testing.T) {
 	t.Parallel()
 
-	ns := New(&deps.Deps{Language: langs.NewDefaultLanguage(config.New())})
+	ns := newNs()
 
 	type expect struct {
 		result  bool