textmachine/backend/internal/chunk/chunktest/epub.go

262 lines
10 KiB
Go

// Package chunktest builds the on-disk source fixtures the ingest path reads. It lives in its own
// package because two packages need the SAME epub shape: the ingest unit tests and the runner's
// end-to-end tests. Duplicating a zip/OPF builder in both would let the two drift apart, and the
// whole point of the e2e fixture is that it is the file the unit tests already pin.
//
// The CONTAINER layer (mimetype first and stored, container.xml, the entry writes) is not built here
// any more: it is internal/bookfile's, the same code the engine's book writer ships an EPUB through, so
// the fixture the reader is pinned against and the file the writer produces cannot drift apart at the
// zip level. What stays here is deliberately the TEST half — the bare OPF stub, the decoy <title>/<style>
// in every chapter head that ingest_test proves are dropped, the MType/EntryName knobs for malformed
// manifests — none of which may ever reach a reader.
package chunktest
import (
"os"
"path/filepath"
"strconv"
"strings"
"testing"
"textmachine/backend/internal/bookfile"
)
type Chapter struct {
ID string
Href string // relative to the OPF dir (OEBPS/), as the MANIFEST spells it
MType string // "" → application/xhtml+xml
Body string // inner xhtml of <body>
// EntryName is the zip entry the file is actually written to (relative to the OPF dir),
// for fixtures whose manifest href does NOT spell the entry name: a percent-encoded href
// or one carrying a #fragment. "" → the href itself, so every existing fixture is unchanged.
EntryName string
// Properties is the OPF manifest `properties` attribute — "nav" marks the navigation document.
Properties string
// Raw writes Body verbatim instead of wrapping it in the xhtml skeleton, for the nav document and
// anything else that must control its own markup.
Raw bool
// Declared writes the manifest item but NOT the file, for a book that promises a document it does not
// carry — the shape a scraped EPUB arrives in.
Declared bool
}
// SpineRef is one spine entry: the manifest id and its `linear` attribute ("" → linear, i.e. absent).
type SpineRef struct {
ID string
Linear string
}
// Nav describes an EPUB 3 navigation document: the toc targets in order and the landmark roles.
type Nav struct {
Href string // "" → "nav.xhtml"
TOC []string // hrefs, relative to the OPF dir
Landmarks map[string]string // href → epub:type ("toc", "cover", …)
// InSpine puts the navigation document in the spine, which real books do and which is exactly the case
// the service-page exclusion has to handle.
InSpine bool
// Missing declares the navigation document in the manifest and omits its bytes.
Missing bool
}
// GuideRef is one EPUB 2 `<guide><reference>`: how a book with no navigation document declares that a
// spine document is its toc or its cover.
type GuideRef struct{ Type, Href string }
// EPUB is a fixture book. The zero value plus Chapters/Spine reproduces what BuildEPUB has always built;
// Nav, NCX and Guide add the structure layers the format work reads.
type EPUB struct {
Chapters []Chapter
Spine []SpineRef
Nav *Nav
NCX []string // EPUB 2 navPoint hrefs, in order; nesting is not needed to test flattening
// NCXBroken writes bytes that are not an NCX, for a book whose spine names one it cannot parse.
NCXBroken bool
// NCXMissing names an NCX in the spine and omits its bytes.
NCXMissing bool
Guide []GuideRef
}
// entryName is where this chapter's bytes are written inside OEBPS/.
func (c Chapter) entryName() string {
if c.EntryName != "" {
return c.EntryName
}
return c.Href
}
// BuildEPUB writes a minimal but real epub (container.xml → OPF → spine → xhtml)
// to a temp .epub file and returns its path. spineIDs gives the reading order
// (may differ from manifest order to prove the spine drives it).
func BuildEPUB(t *testing.T, chapters []Chapter, spineIDs []string) string {
t.Helper()
path := filepath.Join(t.TempDir(), "book.epub")
BuildEPUBAt(t, path, chapters, spineIDs)
return path
}
// Build writes the described book to a temp .epub and returns its path.
func (e EPUB) Build(t *testing.T) string {
t.Helper()
path := filepath.Join(t.TempDir(), "book.epub")
e.BuildAt(t, path)
return path
}
// BuildEPUBAt writes the epub to a caller-chosen path (used by the runner e2e).
func BuildEPUBAt(t *testing.T, path string, chapters []Chapter, spineIDs []string) {
t.Helper()
refs := make([]SpineRef, 0, len(spineIDs))
for _, id := range spineIDs {
refs = append(refs, SpineRef{ID: id})
}
EPUB{Chapters: chapters, Spine: refs}.BuildAt(t, path)
}
// BuildAt writes the described book to a caller-chosen path.
func (e EPUB) BuildAt(t *testing.T, path string) {
t.Helper()
chapters := append([]Chapter(nil), e.Chapters...)
refs := e.Spine
f, err := os.Create(path)
if err != nil {
t.Fatal(err)
}
defer f.Close()
// OCF requires "mimetype" first in the archive and STORED, not deflated, and container.xml pointing
// at the OPF. The production container writes both (bookfile.NewContainer); the fixture rides it so
// it stays the real epub shape the reader will meet, by construction rather than by copy.
c, err := bookfile.NewContainer(f, "OEBPS/content.opf")
if err != nil {
t.Fatal(err)
}
add := func(name, content string) {
if err := c.Add(name, []byte(content)); err != nil {
t.Fatal(err)
}
}
// The navigation document is a manifest item like any other, and real books put it in the spine too.
if e.Nav != nil {
href := e.Nav.Href
if href == "" {
href = "nav.xhtml"
}
chapters = append(chapters, Chapter{ID: "navdoc", Href: href, Properties: "nav", Raw: true,
Body: navXHTML(*e.Nav), Declared: e.Nav.Missing})
if e.Nav.InSpine {
refs = append([]SpineRef{{ID: "navdoc"}}, refs...)
}
}
if len(e.NCX) > 0 || e.NCXBroken || e.NCXMissing {
body := ncxXML(e.NCX)
if e.NCXBroken {
body = "<ncx><navMap><navPoint><unclosed></navMap>" // not an NCX: xml.Unmarshal refuses it
}
chapters = append(chapters, Chapter{ID: "ncx", Href: "toc.ncx", MType: "application/x-dtbncx+xml",
Raw: true, Body: body, Declared: e.NCXMissing})
}
var manifest, spine strings.Builder
for _, c := range chapters {
mt := c.MType
if mt == "" {
mt = "application/xhtml+xml"
}
props := ""
if c.Properties != "" {
props = ` properties="` + c.Properties + `"`
}
manifest.WriteString(`<item id="` + c.ID + `" href="` + c.Href + `" media-type="` + mt + `"` + props + `/>` + "\n")
}
for _, r := range refs {
lin := ""
if r.Linear != "" {
lin = ` linear="` + r.Linear + `"`
}
spine.WriteString(`<itemref idref="` + r.ID + `"` + lin + `/>` + "\n")
}
spineAttr := ""
if len(e.NCX) > 0 || e.NCXBroken || e.NCXMissing {
spineAttr = ` toc="ncx"`
}
var guide strings.Builder
if len(e.Guide) > 0 {
guide.WriteString("<guide>")
for _, g := range e.Guide {
guide.WriteString(`<reference type="` + g.Type + `" href="` + g.Href + `"/>`)
}
guide.WriteString("</guide>")
}
add("OEBPS/content.opf", `<?xml version="1.0" encoding="utf-8"?>
<package xmlns="http://www.idpf.org/2007/opf" version="3.0" unique-identifier="uid">
<metadata xmlns:dc="http://purl.org/dc/elements/1.1/"><dc:title>Test</dc:title></metadata>
<manifest>`+manifest.String()+`</manifest>
<spine`+spineAttr+`>`+spine.String()+`</spine>
`+guide.String()+`
</package>`)
for _, c := range chapters {
// The FILE is (x)html when its ENTRY name says so, regardless of how the manifest
// media-type labels it — real epubs mislabel xhtml as application/xml, etc. The entry
// name (not the href) decides, because an href may be percent-encoded or fragment-bearing.
entry := c.entryName()
if c.Declared {
continue // promised in the manifest, absent from the archive
}
if c.Raw {
add("OEBPS/"+entry, c.Body)
continue
}
switch strings.ToLower(filepath.Ext(entry)) {
case ".xhtml", ".html", ".htm", ".xml":
add("OEBPS/"+entry, `<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml"><head><title>c</title><style>.x{color:red}</style></head>
<body>`+c.Body+`</body></html>`)
default:
add("OEBPS/"+entry, c.Body) // non-xhtml asset (e.g. image bytes stand-in)
}
}
if err := c.Close(); err != nil {
t.Fatal(err)
}
}
// navXHTML renders an EPUB 3 navigation document: a toc nav and, when landmarks are given, a landmarks nav.
// The toc is deliberately NESTED so the flattening rule is exercised by every fixture that uses it.
func navXHTML(n Nav) string {
var toc strings.Builder
for i, h := range n.TOC {
// ⚠ The label is DISTINCT per target and NAMES ITS SOURCE. Writing the same string for every entry —
// as this builder first did — makes a fixture that cannot tell a nav label from an NCX one, nor the
// first entry for a document from the second, so an assertion on titles would pass while reading
// them from the wrong place entirely.
label := "NAV " + h
// The LAST entry is nested one level deeper, so every fixture using a nav exercises flattening.
if i == len(n.TOC)-1 && len(n.TOC) > 1 {
toc.WriteString(`<ol><li><a href="` + h + `">` + label + `</a></li></ol>`)
continue
}
toc.WriteString(`<li><a href="` + h + `">` + label + `</a></li>`)
}
var lm strings.Builder
if len(n.Landmarks) > 0 {
lm.WriteString(`<nav epub:type="landmarks"><ol>`)
for h, role := range n.Landmarks {
lm.WriteString(`<li><a epub:type="` + role + `" href="` + h + `">l</a></li>`)
}
lm.WriteString(`</ol></nav>`)
}
return `<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops"><head><title>nav</title></head>
<body><nav epub:type="toc"><ol>` + toc.String() + `</ol></nav>` + lm.String() + `</body></html>`
}
// ncxXML renders an EPUB 2 NCX with one navPoint per href.
func ncxXML(hrefs []string) string {
var b strings.Builder
for i, h := range hrefs {
b.WriteString(`<navPoint id="np` + strconv.Itoa(i) + `"><navLabel><text>NCX ` + h + `</text></navLabel><content src="` + h + `"/></navPoint>`)
}
return `<?xml version="1.0" encoding="utf-8"?>
<ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" version="2005-1"><navMap>` + b.String() + `</navMap></ncx>`
}