mdBook/src/book/mod.rs

839 lines
27 KiB
Rust

//! The internal representation of a book and infrastructure for loading it from
//! disk and building it.
//!
//! For examples on using `MDBook`, consult the [top-level documentation][1].
//!
//! [1]: ../index.html
#[allow(clippy::module_inception)]
mod book;
mod init;
mod summary;
pub use self::book::{load_book, Book, BookItem, BookItems, Chapter};
pub use self::init::BookBuilder;
pub use self::summary::{parse_summary, Link, SectionNumber, Summary, SummaryItem};
use std::io::Write;
use std::path::PathBuf;
use std::process::Command;
use std::string::ToString;
use tempfile::Builder as TempFileBuilder;
use toml::Value;
use topological_sort::TopologicalSort;
use crate::errors::*;
use crate::preprocess::{
CmdPreprocessor, IndexPreprocessor, LinkPreprocessor, Preprocessor, PreprocessorContext,
};
use crate::renderer::{CmdRenderer, HtmlHandlebars, MarkdownRenderer, RenderContext, Renderer};
use crate::utils;
use crate::config::{Config, RustEdition};
/// The object used to manage and build a book.
pub struct MDBook {
/// The book's root directory.
pub root: PathBuf,
/// The configuration used to tweak now a book is built.
pub config: Config,
/// A representation of the book's contents in memory.
pub book: Book,
renderers: Vec<Box<dyn Renderer>>,
/// List of pre-processors to be run on the book.
preprocessors: Vec<Box<dyn Preprocessor>>,
}
impl MDBook {
/// Load a book from its root directory on disk.
pub fn load<P: Into<PathBuf>>(book_root: P) -> Result<MDBook> {
let book_root = book_root.into();
let config_location = book_root.join("book.toml");
// the book.json file is no longer used, so we should emit a warning to
// let people know to migrate to book.toml
if book_root.join("book.json").exists() {
warn!("It appears you are still using book.json for configuration.");
warn!("This format is no longer used, so you should migrate to the");
warn!("book.toml format.");
warn!("Check the user guide for migration information:");
warn!("\thttps://rust-lang.github.io/mdBook/format/config.html");
}
let mut config = if config_location.exists() {
debug!("Loading config from {}", config_location.display());
Config::from_disk(&config_location)?
} else {
Config::default()
};
config.update_from_env();
if config
.html_config()
.map_or(false, |html| html.google_analytics.is_some())
{
warn!(
"The output.html.google-analytics field has been deprecated; \
it will be removed in a future release.\n\
Consider placing the appropriate site tag code into the \
theme/head.hbs file instead.\n\
The tracking code may be found in the Google Analytics Admin page.\n\
"
);
}
if log_enabled!(log::Level::Trace) {
for line in format!("Config: {:#?}", config).lines() {
trace!("{}", line);
}
}
MDBook::load_with_config(book_root, config)
}
/// Load a book from its root directory using a custom `Config`.
pub fn load_with_config<P: Into<PathBuf>>(book_root: P, config: Config) -> Result<MDBook> {
let root = book_root.into();
let src_dir = root.join(&config.book.src);
let book = book::load_book(&src_dir, &config.build)?;
let renderers = determine_renderers(&config);
let preprocessors = determine_preprocessors(&config)?;
Ok(MDBook {
root,
config,
book,
renderers,
preprocessors,
})
}
/// Load a book from its root directory using a custom `Config` and a custom summary.
pub fn load_with_config_and_summary<P: Into<PathBuf>>(
book_root: P,
config: Config,
summary: Summary,
) -> Result<MDBook> {
let root = book_root.into();
let src_dir = root.join(&config.book.src);
let book = book::load_book_from_disk(&summary, &src_dir)?;
let renderers = determine_renderers(&config);
let preprocessors = determine_preprocessors(&config)?;
Ok(MDBook {
root,
config,
book,
renderers,
preprocessors,
})
}
/// Returns a flat depth-first iterator over the elements of the book,
/// it returns a [`BookItem`] enum:
/// `(section: String, bookitem: &BookItem)`
///
/// ```no_run
/// # use mdbook::MDBook;
/// # use mdbook::book::BookItem;
/// # let book = MDBook::load("mybook").unwrap();
/// for item in book.iter() {
/// match *item {
/// BookItem::Chapter(ref chapter) => {},
/// BookItem::Separator => {},
/// BookItem::PartTitle(ref title) => {}
/// }
/// }
///
/// // would print something like this:
/// // 1. Chapter 1
/// // 1.1 Sub Chapter
/// // 1.2 Sub Chapter
/// // 2. Chapter 2
/// //
/// // etc.
/// ```
pub fn iter(&self) -> BookItems<'_> {
self.book.iter()
}
/// `init()` gives you a `BookBuilder` which you can use to setup a new book
/// and its accompanying directory structure.
///
/// The `BookBuilder` creates some boilerplate files and directories to get
/// you started with your book.
///
/// ```text
/// book-test/
/// ├── book
/// └── src
/// ├── chapter_1.md
/// └── SUMMARY.md
/// ```
///
/// It uses the path provided as the root directory for your book, then adds
/// in a `src/` directory containing a `SUMMARY.md` and `chapter_1.md` file
/// to get you started.
pub fn init<P: Into<PathBuf>>(book_root: P) -> BookBuilder {
BookBuilder::new(book_root)
}
/// Tells the renderer to build our book and put it in the build directory.
pub fn build(&self) -> Result<()> {
info!("Book building has started");
for renderer in &self.renderers {
self.execute_build_process(&**renderer)?;
}
Ok(())
}
/// Run the entire build process for a particular [`Renderer`].
pub fn execute_build_process(&self, renderer: &dyn Renderer) -> Result<()> {
let mut preprocessed_book = self.book.clone();
let preprocess_ctx = PreprocessorContext::new(
self.root.clone(),
self.config.clone(),
renderer.name().to_string(),
);
for preprocessor in &self.preprocessors {
if preprocessor_should_run(&**preprocessor, renderer, &self.config) {
debug!("Running the {} preprocessor.", preprocessor.name());
preprocessed_book = preprocessor.run(&preprocess_ctx, preprocessed_book)?;
}
}
let name = renderer.name();
let build_dir = self.build_dir_for(name);
let mut render_context = RenderContext::new(
self.root.clone(),
preprocessed_book,
self.config.clone(),
build_dir,
);
render_context
.chapter_titles
.extend(preprocess_ctx.chapter_titles.borrow_mut().drain());
info!("Running the {} backend", renderer.name());
renderer
.render(&render_context)
.with_context(|| "Rendering failed")
}
/// You can change the default renderer to another one by using this method.
/// The only requirement is that your renderer implement the [`Renderer`]
/// trait.
pub fn with_renderer<R: Renderer + 'static>(&mut self, renderer: R) -> &mut Self {
self.renderers.push(Box::new(renderer));
self
}
/// Register a [`Preprocessor`] to be used when rendering the book.
pub fn with_preprocessor<P: Preprocessor + 'static>(&mut self, preprocessor: P) -> &mut Self {
self.preprocessors.push(Box::new(preprocessor));
self
}
/// Run `rustdoc` tests on the book, linking against the provided libraries.
pub fn test(&mut self, library_paths: Vec<&str>) -> Result<()> {
let library_args: Vec<&str> = (0..library_paths.len())
.map(|_| "-L")
.zip(library_paths.into_iter())
.flat_map(|x| vec![x.0, x.1])
.collect();
let temp_dir = TempFileBuilder::new().prefix("mdbook-").tempdir()?;
// FIXME: Is "test" the proper renderer name to use here?
let preprocess_context =
PreprocessorContext::new(self.root.clone(), self.config.clone(), "test".to_string());
let book = LinkPreprocessor::new().run(&preprocess_context, self.book.clone())?;
// Index Preprocessor is disabled so that chapter paths continue to point to the
// actual markdown files.
let mut failed = false;
for item in book.iter() {
if let BookItem::Chapter(ref ch) = *item {
let chapter_path = match ch.path {
Some(ref path) if !path.as_os_str().is_empty() => path,
_ => continue,
};
let path = self.source_dir().join(&chapter_path);
info!("Testing file: {:?}", path);
// write preprocessed file to tempdir
let path = temp_dir.path().join(&chapter_path);
let mut tmpf = utils::fs::create_file(&path)?;
tmpf.write_all(ch.content.as_bytes())?;
let mut cmd = Command::new("rustdoc");
cmd.arg(&path).arg("--test").args(&library_args);
if let Some(edition) = self.config.rust.edition {
match edition {
RustEdition::E2015 => {
cmd.args(&["--edition", "2015"]);
}
RustEdition::E2018 => {
cmd.args(&["--edition", "2018"]);
}
RustEdition::E2021 => {
cmd.args(&["--edition", "2021"]);
}
}
}
let output = cmd.output()?;
if !output.status.success() {
failed = true;
error!(
"rustdoc returned an error:\n\
\n--- stdout\n{}\n--- stderr\n{}",
String::from_utf8_lossy(&output.stdout),
String::from_utf8_lossy(&output.stderr)
);
}
}
}
if failed {
bail!("One or more tests failed");
}
Ok(())
}
/// The logic for determining where a backend should put its build
/// artefacts.
///
/// If there is only 1 renderer, put it in the directory pointed to by the
/// `build.build_dir` key in [`Config`]. If there is more than one then the
/// renderer gets its own directory within the main build dir.
///
/// i.e. If there were only one renderer (in this case, the HTML renderer):
///
/// - build/
/// - index.html
/// - ...
///
/// Otherwise if there are multiple:
///
/// - build/
/// - epub/
/// - my_awesome_book.epub
/// - html/
/// - index.html
/// - ...
/// - latex/
/// - my_awesome_book.tex
///
pub fn build_dir_for(&self, backend_name: &str) -> PathBuf {
let build_dir = self.root.join(&self.config.build.build_dir);
if self.renderers.len() <= 1 {
build_dir
} else {
build_dir.join(backend_name)
}
}
/// Get the directory containing this book's source files.
pub fn source_dir(&self) -> PathBuf {
self.root.join(&self.config.book.src)
}
/// Get the directory containing the theme resources for the book.
pub fn theme_dir(&self) -> PathBuf {
self.config
.html_config()
.unwrap_or_default()
.theme_dir(&self.root)
}
}
/// Look at the `Config` and try to figure out what renderers to use.
fn determine_renderers(config: &Config) -> Vec<Box<dyn Renderer>> {
let mut renderers = Vec::new();
if let Some(output_table) = config.get("output").and_then(Value::as_table) {
renderers.extend(output_table.iter().map(|(key, table)| {
if key == "html" {
Box::new(HtmlHandlebars::new()) as Box<dyn Renderer>
} else if key == "markdown" {
Box::new(MarkdownRenderer::new()) as Box<dyn Renderer>
} else {
interpret_custom_renderer(key, table)
}
}));
}
// if we couldn't find anything, add the HTML renderer as a default
if renderers.is_empty() {
renderers.push(Box::new(HtmlHandlebars::new()));
}
renderers
}
const DEFAULT_PREPROCESSORS: &[&'static str] = &["links", "index"];
fn is_default_preprocessor(pre: &dyn Preprocessor) -> bool {
let name = pre.name();
name == LinkPreprocessor::NAME || name == IndexPreprocessor::NAME
}
/// Look at the `MDBook` and try to figure out what preprocessors to run.
fn determine_preprocessors(config: &Config) -> Result<Vec<Box<dyn Preprocessor>>> {
// Collect the names of all preprocessors intended to be run, and the order
// in which they should be run.
let mut preprocessor_names = TopologicalSort::<String>::new();
if config.build.use_default_preprocessors {
for name in DEFAULT_PREPROCESSORS {
preprocessor_names.insert(name.to_string());
}
}
if let Some(preprocessor_table) = config.get("preprocessor").and_then(Value::as_table) {
for (name, table) in preprocessor_table.iter() {
preprocessor_names.insert(name.to_string());
let exists = |name| {
(config.build.use_default_preprocessors && DEFAULT_PREPROCESSORS.contains(&name))
|| preprocessor_table.contains_key(name)
};
if let Some(before) = table.get("before") {
let before = before.as_array().ok_or_else(|| {
Error::msg(format!(
"Expected preprocessor.{}.before to be an array",
name
))
})?;
for after in before {
let after = after.as_str().ok_or_else(|| {
Error::msg(format!(
"Expected preprocessor.{}.before to contain strings",
name
))
})?;
if !exists(after) {
// Only warn so that preprocessors can be toggled on and off (e.g. for
// troubleshooting) without having to worry about order too much.
warn!(
"preprocessor.{}.after contains \"{}\", which was not found",
name, after
);
} else {
preprocessor_names.add_dependency(name, after);
}
}
}
if let Some(after) = table.get("after") {
let after = after.as_array().ok_or_else(|| {
Error::msg(format!(
"Expected preprocessor.{}.after to be an array",
name
))
})?;
for before in after {
let before = before.as_str().ok_or_else(|| {
Error::msg(format!(
"Expected preprocessor.{}.after to contain strings",
name
))
})?;
if !exists(before) {
// See equivalent warning above for rationale
warn!(
"preprocessor.{}.before contains \"{}\", which was not found",
name, before
);
} else {
preprocessor_names.add_dependency(before, name);
}
}
}
}
}
// Now that all links have been established, queue preprocessors in a suitable order
let mut preprocessors = Vec::with_capacity(preprocessor_names.len());
// `pop_all()` returns an empty vector when no more items are not being depended upon
for mut names in std::iter::repeat_with(|| preprocessor_names.pop_all())
.take_while(|names| !names.is_empty())
{
// The `topological_sort` crate does not guarantee a stable order for ties, even across
// runs of the same program. Thus, we break ties manually by sorting.
// Careful: `str`'s default sorting, which we are implicitly invoking here, uses code point
// values ([1]), which may not be an alphabetical sort.
// As mentioned in [1], doing so depends on locale, which is not desirable for deciding
// preprocessor execution order.
// [1]: https://doc.rust-lang.org/stable/std/cmp/trait.Ord.html#impl-Ord-14
names.sort();
for name in names {
let preprocessor: Box<dyn Preprocessor> = match name.as_str() {
"links" => Box::new(LinkPreprocessor::new()),
"index" => Box::new(IndexPreprocessor::new()),
_ => {
// The only way to request a custom preprocessor is through the `preprocessor`
// table, so it must exist, be a table, and contain the key.
let table = &config.get("preprocessor").unwrap().as_table().unwrap()[&name];
let command = get_custom_preprocessor_cmd(&name, table);
Box::new(CmdPreprocessor::new(name, command))
}
};
preprocessors.push(preprocessor);
}
}
// "If `pop_all` returns an empty vector and `len` is not 0, there are cyclic dependencies."
// Normally, `len() == 0` is equivalent to `is_empty()`, so we'll use that.
if preprocessor_names.is_empty() {
Ok(preprocessors)
} else {
Err(Error::msg("Cyclic dependency detected in preprocessors"))
}
}
fn get_custom_preprocessor_cmd(key: &str, table: &Value) -> String {
table
.get("command")
.and_then(Value::as_str)
.map(ToString::to_string)
.unwrap_or_else(|| format!("mdbook-{}", key))
}
fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
// look for the `command` field, falling back to using the key
// prepended by "mdbook-"
let table_dot_command = table
.get("command")
.and_then(Value::as_str)
.map(ToString::to_string);
let command = table_dot_command.unwrap_or_else(|| format!("mdbook-{}", key));
Box::new(CmdRenderer::new(key.to_string(), command))
}
/// Check whether we should run a particular `Preprocessor` in combination
/// with the renderer, falling back to `Preprocessor::supports_renderer()`
/// method if the user doesn't say anything.
///
/// The `build.use-default-preprocessors` config option can be used to ensure
/// default preprocessors always run if they support the renderer.
fn preprocessor_should_run(
preprocessor: &dyn Preprocessor,
renderer: &dyn Renderer,
cfg: &Config,
) -> bool {
// default preprocessors should be run by default (if supported)
if cfg.build.use_default_preprocessors && is_default_preprocessor(preprocessor) {
return preprocessor.supports_renderer(renderer.name());
}
let key = format!("preprocessor.{}.renderers", preprocessor.name());
let renderer_name = renderer.name();
if let Some(Value::Array(ref explicit_renderers)) = cfg.get(&key) {
return explicit_renderers
.iter()
.filter_map(Value::as_str)
.any(|name| name == renderer_name);
}
preprocessor.supports_renderer(renderer_name)
}
#[cfg(test)]
mod tests {
use super::*;
use std::str::FromStr;
use toml::value::{Table, Value};
#[test]
fn config_defaults_to_html_renderer_if_empty() {
let cfg = Config::default();
// make sure we haven't got anything in the `output` table
assert!(cfg.get("output").is_none());
let got = determine_renderers(&cfg);
assert_eq!(got.len(), 1);
assert_eq!(got[0].name(), "html");
}
#[test]
fn add_a_random_renderer_to_the_config() {
let mut cfg = Config::default();
cfg.set("output.random", Table::new()).unwrap();
let got = determine_renderers(&cfg);
assert_eq!(got.len(), 1);
assert_eq!(got[0].name(), "random");
}
#[test]
fn add_a_random_renderer_with_custom_command_to_the_config() {
let mut cfg = Config::default();
let mut table = Table::new();
table.insert("command".to_string(), Value::String("false".to_string()));
cfg.set("output.random", table).unwrap();
let got = determine_renderers(&cfg);
assert_eq!(got.len(), 1);
assert_eq!(got[0].name(), "random");
}
#[test]
fn config_defaults_to_link_and_index_preprocessor_if_not_set() {
let cfg = Config::default();
// make sure we haven't got anything in the `preprocessor` table
assert!(cfg.get("preprocessor").is_none());
let got = determine_preprocessors(&cfg);
assert!(got.is_ok());
assert_eq!(got.as_ref().unwrap().len(), 2);
assert_eq!(got.as_ref().unwrap()[0].name(), "index");
assert_eq!(got.as_ref().unwrap()[1].name(), "links");
}
#[test]
fn use_default_preprocessors_works() {
let mut cfg = Config::default();
cfg.build.use_default_preprocessors = false;
let got = determine_preprocessors(&cfg).unwrap();
assert_eq!(got.len(), 0);
}
#[test]
fn can_determine_third_party_preprocessors() {
let cfg_str = r#"
[book]
title = "Some Book"
[preprocessor.random]
[build]
build-dir = "outputs"
create-missing = false
"#;
let cfg = Config::from_str(cfg_str).unwrap();
// make sure the `preprocessor.random` table exists
assert!(cfg.get_preprocessor("random").is_some());
let got = determine_preprocessors(&cfg).unwrap();
assert!(got.into_iter().any(|p| p.name() == "random"));
}
#[test]
fn preprocessors_can_provide_their_own_commands() {
let cfg_str = r#"
[preprocessor.random]
command = "python random.py"
"#;
let cfg = Config::from_str(cfg_str).unwrap();
// make sure the `preprocessor.random` table exists
let random = cfg.get_preprocessor("random").unwrap();
let random = get_custom_preprocessor_cmd("random", &Value::Table(random.clone()));
assert_eq!(random, "python random.py");
}
#[test]
fn preprocessor_before_must_be_array() {
let cfg_str = r#"
[preprocessor.random]
before = 0
"#;
let cfg = Config::from_str(cfg_str).unwrap();
assert!(determine_preprocessors(&cfg).is_err());
}
#[test]
fn preprocessor_after_must_be_array() {
let cfg_str = r#"
[preprocessor.random]
after = 0
"#;
let cfg = Config::from_str(cfg_str).unwrap();
assert!(determine_preprocessors(&cfg).is_err());
}
#[test]
fn preprocessor_order_is_honored() {
let cfg_str = r#"
[preprocessor.random]
before = [ "last" ]
after = [ "index" ]
[preprocessor.last]
after = [ "links", "index" ]
"#;
let cfg = Config::from_str(cfg_str).unwrap();
let preprocessors = determine_preprocessors(&cfg).unwrap();
let index = |name| {
preprocessors
.iter()
.enumerate()
.find(|(_, preprocessor)| preprocessor.name() == name)
.unwrap()
.0
};
let assert_before = |before, after| {
if index(before) >= index(after) {
eprintln!("Preprocessor order:");
for preprocessor in &preprocessors {
eprintln!(" {}", preprocessor.name());
}
panic!("{} should come before {}", before, after);
}
};
assert_before("index", "random");
assert_before("index", "last");
assert_before("random", "last");
assert_before("links", "last");
}
#[test]
fn cyclic_dependencies_are_detected() {
let cfg_str = r#"
[preprocessor.links]
before = [ "index" ]
[preprocessor.index]
before = [ "links" ]
"#;
let cfg = Config::from_str(cfg_str).unwrap();
assert!(determine_preprocessors(&cfg).is_err());
}
#[test]
fn dependencies_dont_register_undefined_preprocessors() {
let cfg_str = r#"
[preprocessor.links]
before = [ "random" ]
"#;
let cfg = Config::from_str(cfg_str).unwrap();
let preprocessors = determine_preprocessors(&cfg).unwrap();
assert!(preprocessors
.iter()
.find(|preprocessor| preprocessor.name() == "random")
.is_none());
}
#[test]
fn dependencies_dont_register_builtin_preprocessors_if_disabled() {
let cfg_str = r#"
[preprocessor.random]
before = [ "links" ]
[build]
use-default-preprocessors = false
"#;
let cfg = Config::from_str(cfg_str).unwrap();
let preprocessors = determine_preprocessors(&cfg).unwrap();
assert!(preprocessors
.iter()
.find(|preprocessor| preprocessor.name() == "links")
.is_none());
}
#[test]
fn config_respects_preprocessor_selection() {
let cfg_str = r#"
[preprocessor.links]
renderers = ["html"]
"#;
let cfg = Config::from_str(cfg_str).unwrap();
// double-check that we can access preprocessor.links.renderers[0]
let html = cfg
.get_preprocessor("links")
.and_then(|links| links.get("renderers"))
.and_then(Value::as_array)
.and_then(|renderers| renderers.get(0))
.and_then(Value::as_str)
.unwrap();
assert_eq!(html, "html");
let html_renderer = HtmlHandlebars::default();
let pre = LinkPreprocessor::new();
let should_run = preprocessor_should_run(&pre, &html_renderer, &cfg);
assert!(should_run);
}
struct BoolPreprocessor(bool);
impl Preprocessor for BoolPreprocessor {
fn name(&self) -> &str {
"bool-preprocessor"
}
fn run(&self, _ctx: &PreprocessorContext, _book: Book) -> Result<Book> {
unimplemented!()
}
fn supports_renderer(&self, _renderer: &str) -> bool {
self.0
}
}
#[test]
fn preprocessor_should_run_falls_back_to_supports_renderer_method() {
let cfg = Config::default();
let html = HtmlHandlebars::new();
let should_be = true;
let got = preprocessor_should_run(&BoolPreprocessor(should_be), &html, &cfg);
assert_eq!(got, should_be);
let should_be = false;
let got = preprocessor_should_run(&BoolPreprocessor(should_be), &html, &cfg);
assert_eq!(got, should_be);
}
}