all: Rework page store, add a dynacache, improve partial rebuilds, and some general spring cleaningdevelop2024

There are some breaking changes in this commit, see #11455.

Closes #11455
Closes #11549

This fixes a set of bugs (see issue list) and it is also paying some technical debt accumulated over the years. We now build with Staticcheck enabled in the CI build.

The performance should be about the same as before for regular sized Hugo sites, but it should perform and scale much better to larger data sets, as objects that uses lots of memory (e.g. rendered Markdown, big JSON files read into maps with transform.Unmarshal etc.) will now get automatically garbage collected if needed. Performance on partial rebuilds when running the server in fast render mode should be the same, but the change detection should be much more accurate.

A list of the notable new features:

* A new dependency tracker that covers (almost) all of Hugo's API and is used to do fine grained partial rebuilds when running the server.
* A new and simpler tree document store which allows fast lookups and prefix-walking in all dimensions (e.g. language) concurrently.
* You can now configure an upper memory limit allowing for much larger data sets and/or running on lower specced PCs.
We have lifted the "no resources in sub folders" restriction for branch bundles (e.g. sections).
Memory Limit
* Hugos will, by default, set aside a quarter of the total system memory, but you can set this via the OS environment variable HUGO_MEMORYLIMIT (in gigabytes). This is backed by a partitioned LRU cache used throughout Hugo. A cache that gets dynamically resized in low memory situations, allowing Go's Garbage Collector to free the memory.

New Dependency Tracker: Hugo has had a rule based coarse grained approach to server rebuilds that has worked mostly pretty well, but there have been some surprises (e.g. stale content). This is now revamped with a new dependency tracker that can quickly calculate the delta given a changed resource (e.g. a content file, template, JS file etc.). This handles transitive relations, e.g. $page -> js.Build -> JS import, or $page1.Content -> render hook -> site.GetPage -> $page2.Title, or $page1.Content -> shortcode -> partial -> site.RegularPages -> $page2.Content -> shortcode ..., and should also handle changes to aggregated values (e.g. site.Lastmod) effectively.

This covers all of Hugo's API with 2 known exceptions (a list that may not be fully exhaustive):

Changes to files loaded with template func os.ReadFile may not be handled correctly. We recommend loading resources with resources.Get
Changes to Hugo objects (e.g. Page) passed in the template context to lang.Translate may not be detected correctly. We recommend having simple i18n templates without too much data context passed in other than simple types such as strings and numbers.
Note that the cachebuster configuration (when A changes then rebuild B) works well with the above, but we recommend that you revise that configuration, as it in most situations should not be needed. One example where it is still needed is with TailwindCSS and using changes to hugo_stats.json to trigger new CSS rebuilds.

Document Store: Previously, a little simplified, we split the document store (where we store pages and resources) in a tree per language. This worked pretty well, but the structure made some operations harder than they needed to be. We have now restructured it into one Radix tree for all languages. Internally the language is considered to be a dimension of that tree, and the tree can be viewed in all dimensions concurrently. This makes some operations re. language simpler (e.g. finding translations is just a slice range), but the idea is that it should also be relatively inexpensive to add more dimensions if needed (e.g. role).

Fixes #10169
Fixes #10364
Fixes #10482
Fixes #10630
Fixes #10656
Fixes #10694
Fixes #10918
Fixes #11262
Fixes #11439
Fixes #11453
Fixes #11457
Fixes #11466
Fixes #11540
Fixes #11551
Fixes #11556
Fixes #11654
Fixes #11661
Fixes #11663
Fixes #11664
Fixes #11669
Fixes #11671
Fixes #11807
Fixes #11808
Fixes #11809
Fixes #11815
Fixes #11840
Fixes #11853
Fixes #11860
Fixes #11883
Fixes #11904
Fixes #7388
Fixes #7425
Fixes #7436
Fixes #7544
Fixes #7882
Fixes #7960
Fixes #8255
Fixes #8307
Fixes #8863
Fixes #8927
Fixes #9192
Fixes #9324

6 files changed, 88 insertions, 404 deletions

diff --git a/source/content_directory_test.go b/source/content_directory_test.go
index 7d1630529..96ee22bc7 100644
--- a/source/content_directory_test.go
+++ b/source/content_directory_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 The Hugo Authors. All rights reserved.
+// Copyright 2024 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.
diff --git a/source/fileInfo.go b/source/fileInfo.go
index 60c6e6ea8..5b24bbeb2 100644
--- a/source/fileInfo.go
+++ b/source/fileInfo.go
@@ -14,9 +14,7 @@
 package source
 
 import (
-	"fmt"
 	"path/filepath"
-	"strings"
 	"sync"
 	"time"
 
@@ -24,8 +22,6 @@ import (
 	"github.com/gohugoio/hugo/common/hugo"
 	"github.com/gohugoio/hugo/common/paths"
 
-	"github.com/gohugoio/hugo/hugofs/files"
-
 	"github.com/gohugoio/hugo/common/hugio"
 
 	"github.com/gohugoio/hugo/hugofs"
@@ -33,269 +29,121 @@ import (
 	"github.com/gohugoio/hugo/helpers"
 )
 
-// fileInfo implements the File interface.
-var (
-	_ File = (*FileInfo)(nil)
-)
-
-// File represents a source file.
-// This is a temporary construct until we resolve page.Page conflicts.
-// TODO(bep) remove this construct once we have resolved page deprecations
-type File interface {
-	fileOverlap
-	FileWithoutOverlap
-}
-
-// Temporary to solve duplicate/deprecated names in page.Page
-type fileOverlap interface {
-	// Path gets the relative path including file name and extension.
-	// The directory is relative to the content root.
-	Path() string
-
-	// Section is first directory below the content root.
-	// For page bundles in root, the Section will be empty.
-	Section() string
-
-	// Lang is the language code for this page. It will be the
-	// same as the site's language code.
-	Lang() string
-
-	IsZero() bool
-}
-
-type FileWithoutOverlap interface {
-	// Filename gets the full path and filename to the file.
-	Filename() string
-
-	// Dir gets the name of the directory that contains this file.
-	// The directory is relative to the content root.
-	Dir() string
-
-	// Extension is an alias to Ext().
-	// Deprecated: Use Ext instead.
-	Extension() string
-
-	// Ext gets the file extension, i.e "myblogpost.md" will return "md".
-	Ext() string
-
-	// LogicalName is filename and extension of the file.
-	LogicalName() string
-
-	// BaseFileName is a filename without extension.
-	BaseFileName() string
-
-	// TranslationBaseName is a filename with no extension,
-	// not even the optional language extension part.
-	TranslationBaseName() string
-
-	// ContentBaseName is a either TranslationBaseName or name of containing folder
-	// if file is a leaf bundle.
-	ContentBaseName() string
-
-	// UniqueID is the MD5 hash of the file's path and is for most practical applications,
-	// Hugo content files being one of them, considered to be unique.
-	UniqueID() string
-
-	// For internal use only.
-	FileInfo() hugofs.FileMetaInfo
-}
-
-// FileInfo describes a source file.
-type FileInfo struct {
-	// Absolute filename to the file on disk.
-	filename string
-
-	sp *SourceSpec
-
-	fi hugofs.FileMetaInfo
-
-	// Derived from filename
-	ext  string // Extension without any "."
-	lang string
-
-	name string
-
-	dir                 string
-	relDir              string
-	relPath             string
-	baseName            string
-	translationBaseName string
-	contentBaseName     string
-	section             string
-	classifier          files.ContentClass
+// File describes a source file.
+type File struct {
+	fim hugofs.FileMetaInfo
 
 	uniqueID string
-
 	lazyInit sync.Once
 }
 
 // Filename returns a file's absolute path and filename on disk.
-func (fi *FileInfo) Filename() string { return fi.filename }
+func (fi *File) Filename() string { return fi.fim.Meta().Filename }
 
 // Path gets the relative path including file name and extension.  The directory
 // is relative to the content root.
-func (fi *FileInfo) Path() string { return fi.relPath }
+func (fi *File) Path() string { return filepath.Join(fi.p().Dir()[1:], fi.p().Name()) }
 
 // Dir gets the name of the directory that contains this file.  The directory is
 // relative to the content root.
-func (fi *FileInfo) Dir() string { return fi.relDir }
+func (fi *File) Dir() string {
+	return fi.pathToDir(fi.p().Dir())
+}
 
 // Extension is an alias to Ext().
-func (fi *FileInfo) Extension() string {
+func (fi *File) Extension() string {
 	hugo.Deprecate(".File.Extension", "Use .File.Ext instead.", "v0.96.0")
 	return fi.Ext()
 }
 
-// Ext returns a file's extension without the leading period (ie. "md").
-func (fi *FileInfo) Ext() string { return fi.ext }
+// Ext returns a file's extension without the leading period (e.g. "md").
+// Deprecated: Use Extension() instead.
+func (fi *File) Ext() string { return fi.p().Ext() }
 
-// Lang returns a file's language (ie. "sv").
-func (fi *FileInfo) Lang() string { return fi.lang }
+// Lang returns a file's language (e.g. "sv").
+func (fi *File) Lang() string {
+	return fi.fim.Meta().Lang
+}
 
-// LogicalName returns a file's name and extension (ie. "page.sv.md").
-func (fi *FileInfo) LogicalName() string { return fi.name }
+// LogicalName returns a file's name and extension (e.g. "page.sv.md").
+func (fi *File) LogicalName() string {
+	return fi.p().Name()
+}
 
-// BaseFileName returns a file's name without extension (ie. "page.sv").
-func (fi *FileInfo) BaseFileName() string { return fi.baseName }
+// BaseFileName returns a file's name without extension (e.g. "page.sv").
+func (fi *File) BaseFileName() string {
+	return fi.p().NameNoExt()
+}
 
 // TranslationBaseName returns a file's translation base name without the
-// language segment (ie. "page").
-func (fi *FileInfo) TranslationBaseName() string { return fi.translationBaseName }
+// language segment (e.g. "page").
+func (fi *File) TranslationBaseName() string { return fi.p().NameNoIdentifier() }
 
 // ContentBaseName is a either TranslationBaseName or name of containing folder
-// if file is a leaf bundle.
-func (fi *FileInfo) ContentBaseName() string {
-	fi.init()
-	return fi.contentBaseName
+// if file is a bundle.
+func (fi *File) ContentBaseName() string {
+	return fi.p().BaseNameNoIdentifier()
 }
 
 // Section returns a file's section.
-func (fi *FileInfo) Section() string {
-	fi.init()
-	return fi.section
+func (fi *File) Section() string {
+	return fi.p().Section()
 }
 
 // UniqueID returns a file's unique, MD5 hash identifier.
-func (fi *FileInfo) UniqueID() string {
+func (fi *File) UniqueID() string {
 	fi.init()
 	return fi.uniqueID
 }
 
 // FileInfo returns a file's underlying os.FileInfo.
-// For internal use only.
-func (fi *FileInfo) FileInfo() hugofs.FileMetaInfo { return fi.fi }
+func (fi *File) FileInfo() hugofs.FileMetaInfo { return fi.fim }
 
-func (fi *FileInfo) String() string { return fi.BaseFileName() }
+func (fi *File) String() string { return fi.BaseFileName() }
 
 // Open implements ReadableFile.
-func (fi *FileInfo) Open() (hugio.ReadSeekCloser, error) {
-	f, err := fi.fi.Meta().Open()
+func (fi *File) Open() (hugio.ReadSeekCloser, error) {
+	f, err := fi.fim.Meta().Open()
 
 	return f, err
 }
 
-func (fi *FileInfo) IsZero() bool {
+func (fi *File) IsZero() bool {
 	return fi == nil
 }
 
 // We create a lot of these FileInfo objects, but there are parts of it used only
 // in some cases that is slightly expensive to construct.
-func (fi *FileInfo) init() {
+func (fi *File) init() {
 	fi.lazyInit.Do(func() {
-		relDir := strings.Trim(fi.relDir, helpers.FilePathSeparator)
-		parts := strings.Split(relDir, helpers.FilePathSeparator)
-		var section string
-		if (fi.classifier != files.ContentClassLeaf && len(parts) == 1) || len(parts) > 1 {
-			section = parts[0]
-		}
-		fi.section = section
-
-		if fi.classifier.IsBundle() && len(parts) > 0 {
-			fi.contentBaseName = parts[len(parts)-1]
-		} else {
-			fi.contentBaseName = fi.translationBaseName
-		}
-
-		fi.uniqueID = helpers.MD5String(filepath.ToSlash(fi.relPath))
+		fi.uniqueID = helpers.MD5String(filepath.ToSlash(fi.Path()))
 	})
 }
 
-// NewTestFile creates a partially filled File used in unit tests.
-// TODO(bep) improve this package
-func NewTestFile(filename string) *FileInfo {
-	base := filepath.Base(filepath.Dir(filename))
-	return &FileInfo{
-		filename:            filename,
-		translationBaseName: base,
+func (fi *File) pathToDir(s string) string {
+	if s == "" {
+		return s
 	}
+	return filepath.FromSlash(s[1:] + "/")
 }
 
-func (sp *SourceSpec) NewFileInfoFrom(path, filename string) (*FileInfo, error) {
+func (fi *File) p() *paths.Path {
+	return fi.fim.Meta().PathInfo
+}
+
+func NewFileInfoFrom(path, filename string) *File {
 	meta := &hugofs.FileMeta{
 		Filename: filename,
-		Path:     path,
+		PathInfo: paths.Parse("", filepath.ToSlash(path)),
 	}
 
-	return sp.NewFileInfo(hugofs.NewFileMetaInfo(nil, meta))
+	return NewFileInfo(hugofs.NewFileMetaInfo(nil, meta))
 }
 
-func (sp *SourceSpec) NewFileInfo(fi hugofs.FileMetaInfo) (*FileInfo, error) {
-	m := fi.Meta()
-
-	filename := m.Filename
-	relPath := m.Path
-
-	if relPath == "" {
-		return nil, fmt.Errorf("no Path provided by %v (%T)", m, m.Fs)
-	}
-
-	if filename == "" {
-		return nil, fmt.Errorf("no Filename provided by %v (%T)", m, m.Fs)
+func NewFileInfo(fi hugofs.FileMetaInfo) *File {
+	return &File{
+		fim: fi,
 	}
-
-	relDir := filepath.Dir(relPath)
-	if relDir == "." {
-		relDir = ""
-	}
-	if !strings.HasSuffix(relDir, helpers.FilePathSeparator) {
-		relDir = relDir + helpers.FilePathSeparator
-	}
-
-	lang := m.Lang
-	translationBaseName := m.TranslationBaseName
-
-	dir, name := filepath.Split(relPath)
-	if !strings.HasSuffix(dir, helpers.FilePathSeparator) {
-		dir = dir + helpers.FilePathSeparator
-	}
-
-	ext := strings.ToLower(strings.TrimPrefix(filepath.Ext(name), "."))
-	baseName := paths.Filename(name)
-
-	if translationBaseName == "" {
-		// This is usually provided by the filesystem. But this FileInfo is also
-		// created in a standalone context when doing "hugo new". This is
-		// an approximate implementation, which is "good enough" in that case.
-		fileLangExt := filepath.Ext(baseName)
-		translationBaseName = strings.TrimSuffix(baseName, fileLangExt)
-	}
-
-	f := &FileInfo{
-		sp:                  sp,
-		filename:            filename,
-		fi:                  fi,
-		lang:                lang,
-		ext:                 ext,
-		dir:                 dir,
-		relDir:              relDir,  // Dir()
-		relPath:             relPath, // Path()
-		name:                name,
-		baseName:            baseName, // BaseFileName()
-		translationBaseName: translationBaseName,
-		classifier:          m.Classifier,
-	}
-
-	return f, nil
 }
 
 func NewGitInfo(info gitmap.GitInfo) GitInfo {
diff --git a/source/fileInfo_test.go b/source/fileInfo_test.go
deleted file mode 100644
index e2a3edd30..000000000
--- a/source/fileInfo_test.go
+++ /dev/null
@@ -1,58 +0,0 @@
-// Copyright 2017-present 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 source_test
-
-import (
-	"path/filepath"
-	"strings"
-	"testing"
-
-	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/source"
-)
-
-func TestFileInfo(t *testing.T) {
-	c := qt.New(t)
-
-	s := newTestSourceSpec()
-
-	for _, this := range []struct {
-		base     string
-		filename string
-		assert   func(f *source.FileInfo)
-	}{
-		{filepath.FromSlash("/a/"), filepath.FromSlash("/a/b/page.md"), func(f *source.FileInfo) {
-			c.Assert(f.Filename(), qt.Equals, filepath.FromSlash("/a/b/page.md"))
-			c.Assert(f.Dir(), qt.Equals, filepath.FromSlash("b/"))
-			c.Assert(f.Path(), qt.Equals, filepath.FromSlash("b/page.md"))
-			c.Assert(f.Section(), qt.Equals, "b")
-			c.Assert(f.TranslationBaseName(), qt.Equals, filepath.FromSlash("page"))
-			c.Assert(f.BaseFileName(), qt.Equals, filepath.FromSlash("page"))
-		}},
-		{filepath.FromSlash("/a/"), filepath.FromSlash("/a/b/c/d/page.md"), func(f *source.FileInfo) {
-			c.Assert(f.Section(), qt.Equals, "b")
-		}},
-		{filepath.FromSlash("/a/"), filepath.FromSlash("/a/b/page.en.MD"), func(f *source.FileInfo) {
-			c.Assert(f.Section(), qt.Equals, "b")
-			c.Assert(f.Path(), qt.Equals, filepath.FromSlash("b/page.en.MD"))
-			c.Assert(f.TranslationBaseName(), qt.Equals, filepath.FromSlash("page"))
-			c.Assert(f.BaseFileName(), qt.Equals, filepath.FromSlash("page.en"))
-		}},
-	} {
-		path := strings.TrimPrefix(this.filename, this.base)
-		f, err := s.NewFileInfoFrom(path, this.filename)
-		c.Assert(err, qt.IsNil)
-		this.assert(f)
-	}
-}
diff --git a/source/filesystem.go b/source/filesystem.go
index 283863dbf..208f5036f 100644
--- a/source/filesystem.go
+++ b/source/filesystem.go
@@ -14,66 +14,27 @@
 package source
 
 import (
-	"fmt"
 	"path/filepath"
-	"sync"
 
 	"github.com/gohugoio/hugo/hugofs"
+	"github.com/spf13/afero"
 )
 
 // Filesystem represents a source filesystem.
 type Filesystem struct {
-	files        []File
-	filesInit    sync.Once
-	filesInitErr error
-
 	Base string
-
-	fi hugofs.FileMetaInfo
-
+	fs   afero.Fs
+	fi   hugofs.FileMetaInfo
 	SourceSpec
 }
 
-// NewFilesystem returns a new filesystem for a given source spec.
+// NewFilesystem returns a new filesytem for a given source spec.
 func (sp SourceSpec) NewFilesystem(base string) *Filesystem {
-	return &Filesystem{SourceSpec: sp, Base: base}
+	return &Filesystem{SourceSpec: sp, Base: base, fs: sp.Fs.Source}
 }
 
-func (sp SourceSpec) NewFilesystemFromFileMetaInfo(fi hugofs.FileMetaInfo) *Filesystem {
-	return &Filesystem{SourceSpec: sp, fi: fi}
-}
-
-// Files returns a slice of readable files.
-func (f *Filesystem) Files() ([]File, error) {
-	f.filesInit.Do(func() {
-		err := f.captureFiles()
-		if err != nil {
-			f.filesInitErr = fmt.Errorf("capture files: %w", err)
-		}
-	})
-	return f.files, f.filesInitErr
-}
-
-// add populates a file in the Filesystem.files
-func (f *Filesystem) add(name string, fi hugofs.FileMetaInfo) (err error) {
-	var file File
-
-	file, err = f.SourceSpec.NewFileInfo(fi)
-	if err != nil {
-		return err
-	}
-
-	f.files = append(f.files, file)
-
-	return err
-}
-
-func (f *Filesystem) captureFiles() error {
-	walker := func(path string, fi hugofs.FileMetaInfo, err error) error {
-		if err != nil {
-			return err
-		}
-
+func (f *Filesystem) Walk(addFile func(*File) error) error {
+	walker := func(path string, fi hugofs.FileMetaInfo) error {
 		if fi.IsDir() {
 			return nil
 		}
@@ -87,14 +48,16 @@ func (f *Filesystem) captureFiles() error {
 		}
 
 		if b {
-			err = f.add(filename, fi)
+			if err = addFile(NewFileInfo(fi)); err != nil {
+				return err
+			}
 		}
 
 		return err
 	}
 
 	w := hugofs.NewWalkway(hugofs.WalkwayConfig{
-		Fs:     f.SourceFs,
+		Fs:     f.fs,
 		Info:   f.fi,
 		Root:   f.Base,
 		WalkFn: walker,
diff --git a/source/filesystem_test.go b/source/filesystem_test.go
index 1067d5839..9118285da 100644
--- a/source/filesystem_test.go
+++ b/source/filesystem_test.go
@@ -1,4 +1,4 @@
-// Copyright 2023 The Hugo Authors. All rights reserved.
+// Copyright 2024 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.
@@ -14,71 +14,35 @@
 package source_test
 
 import (
-	"fmt"
-	"path/filepath"
 	"runtime"
 	"testing"
 
-	"github.com/spf13/afero"
-
 	qt "github.com/frankban/quicktest"
-	"github.com/gohugoio/hugo/config"
-	"github.com/gohugoio/hugo/config/testconfig"
-	"github.com/gohugoio/hugo/helpers"
-	"github.com/gohugoio/hugo/hugofs"
-	"github.com/gohugoio/hugo/source"
+	"github.com/gohugoio/hugo/hugolib"
+	"golang.org/x/text/unicode/norm"
 )
 
-func TestEmptySourceFilesystem(t *testing.T) {
-	c := qt.New(t)
-	ss := newTestSourceSpec()
-	src := ss.NewFilesystem("")
-	files, err := src.Files()
-	c.Assert(err, qt.IsNil)
-	if len(files) != 0 {
-		t.Errorf("new filesystem should contain 0 files.")
-	}
-}
-
 func TestUnicodeNorm(t *testing.T) {
 	if runtime.GOOS != "darwin" {
-		// Normalization code is only for Mac OS, since it is not necessary for other OSes.
-		return
-	}
-
-	c := qt.New(t)
-
-	paths := []struct {
-		NFC string
-		NFD string
-	}{
-		{NFC: "å", NFD: "\x61\xcc\x8a"},
-		{NFC: "é", NFD: "\x65\xcc\x81"},
-	}
-
-	ss := newTestSourceSpec()
-
-	for i, path := range paths {
-		base := fmt.Sprintf("base%d", i)
-		c.Assert(afero.WriteFile(ss.Fs.Source, filepath.Join(base, path.NFD), []byte("some data"), 0777), qt.IsNil)
-		src := ss.NewFilesystem(base)
-		files, err := src.Files()
-		c.Assert(err, qt.IsNil)
-		f := files[0]
-		if f.BaseFileName() != path.NFC {
-			t.Fatalf("file %q name in NFD form should be normalized (%s)", f.BaseFileName(), path.NFC)
-		}
+		t.Skip("Skipping test on non-Darwin OS")
 	}
-}
-
-func newTestSourceSpec() *source.SourceSpec {
-	v := config.New()
-	afs := hugofs.NewBaseFileDecorator(afero.NewMemMapFs())
-	conf := testconfig.GetTestConfig(afs, v)
-	fs := hugofs.NewFrom(afs, conf.BaseConfig())
-	ps, err := helpers.NewPathSpec(fs, conf, nil)
-	if err != nil {
-		panic(err)
+	t.Parallel()
+	files := `
+-- hugo.toml --
+-- content/å.md --
+-- content/é.md --
+-- content/å/å.md --
+-- content/é/é.md --
+-- layouts/_default/single.html --
+Title: {{ .Title }}|File: {{ .File.Path}}
+`
+	b := hugolib.Test(t, files, hugolib.TestOptWithNFDOnDarwin())
+
+	for _, p := range b.H.Sites[0].RegularPages() {
+		f := p.File()
+		b.Assert(norm.NFC.IsNormalString(f.Path()), qt.IsTrue)
+		b.Assert(norm.NFC.IsNormalString(f.Dir()), qt.IsTrue)
+		b.Assert(norm.NFC.IsNormalString(f.Filename()), qt.IsTrue)
+		b.Assert(norm.NFC.IsNormalString(f.BaseFileName()), qt.IsTrue)
 	}
-	return source.NewSourceSpec(ps, nil, fs.Source)
 }
diff --git a/source/sourceSpec.go b/source/sourceSpec.go
index dc44994a8..ea1b977f3 100644
--- a/source/sourceSpec.go
+++ b/source/sourceSpec.go
@@ -1,4 +1,4 @@
-// Copyright 2023 The Hugo Authors. All rights reserved.
+// Copyright 2024 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.
@@ -15,7 +15,6 @@
 package source
 
 import (
-	"os"
 	"path/filepath"
 	"runtime"
 
@@ -38,7 +37,6 @@ type SourceSpec struct {
 
 // NewSourceSpec initializes SourceSpec using languages the given filesystem and PathSpec.
 func NewSourceSpec(ps *helpers.PathSpec, inclusionFilter *glob.FilenameFilter, fs afero.Fs) *SourceSpec {
-
 	shouldInclude := func(filename string) bool {
 		if !inclusionFilter.Match(filename, false) {
 			return false
@@ -90,34 +88,3 @@ func (s *SourceSpec) IgnoreFile(filename string) bool {
 
 	return false
 }
-
-// IsRegularSourceFile returns whether filename represents a regular file in the
-// source filesystem.
-func (s *SourceSpec) IsRegularSourceFile(filename string) (bool, error) {
-	fi, err := helpers.LstatIfPossible(s.SourceFs, filename)
-	if err != nil {
-		return false, err
-	}
-
-	if fi.IsDir() {
-		return false, nil
-	}
-
-	if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
-		link, err := filepath.EvalSymlinks(filename)
-		if err != nil {
-			return false, err
-		}
-
-		fi, err = helpers.LstatIfPossible(s.SourceFs, link)
-		if err != nil {
-			return false, err
-		}
-
-		if fi.IsDir() {
-			return false, nil
-		}
-	}
-
-	return true, nil
-}