mdBook/src/config.rs

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//! Mdbook's configuration system.
//!
//! The main entrypoint of the `config` module is the `Config` struct. This acts
//! essentially as a bag of configuration information, with a couple
//! pre-determined tables (`BookConfig` and `BuildConfig`) as well as support
//! for arbitrary data which is exposed to plugins and alternate backends.
//!
//!
//! # Examples
//!
//! ```rust
//! # extern crate mdbook;
//! # use mdbook::errors::*;
//! # extern crate toml;
//! use std::path::PathBuf;
//! use mdbook::Config;
//! use toml::Value;
//!
//! # fn run() -> Result<()> {
//! let src = r#"
//! [book]
//! title = "My Book"
//! authors = ["Michael-F-Bryan"]
//!
//! [build]
//! src = "out"
//!
//! [other-table.foo]
//! bar = 123
//! "#;
//!
//! // load the `Config` from a toml string
//! let mut cfg = Config::from_str(src)?;
//!
//! // retrieve a nested value
//! let bar = cfg.get("other-table.foo.bar").cloned();
//! assert_eq!(bar, Some(Value::Integer(123)));
//!
//! // Set the `output.html.theme` directory
//! assert!(cfg.get("output.html").is_none());
//! cfg.set("output.html.theme", "./themes");
//!
//! // then load it again, automatically deserializing to a `PathBuf`.
//! let got: PathBuf = cfg.get_deserialized("output.html.theme")?;
//! assert_eq!(got, PathBuf::from("./themes"));
//! # Ok(())
//! # }
//! # fn main() { run().unwrap() }
//! ```
#![deny(missing_docs)]
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use serde::{Deserialize, Deserializer, Serialize, Serializer};
use serde_json;
use std::env;
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use std::fs::File;
use std::io::Read;
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use std::path::{Path, PathBuf};
use toml::value::Table;
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use toml::{self, Value};
use toml_query::delete::TomlValueDeleteExt;
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use toml_query::insert::TomlValueInsertExt;
use toml_query::read::TomlValueReadExt;
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use errors::*;
/// The overall configuration object for MDBook, essentially an in-memory
/// representation of `book.toml`.
#[derive(Debug, Clone, PartialEq)]
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pub struct Config {
/// Metadata about the book.
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pub book: BookConfig,
/// Information about the build environment.
pub build: BuildConfig,
rest: Value,
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}
impl Config {
/// Load a `Config` from some string.
pub fn from_str(src: &str) -> Result<Config> {
toml::from_str(src).chain_err(|| Error::from("Invalid configuration file"))
}
/// Load the configuration file from disk.
pub fn from_disk<P: AsRef<Path>>(config_file: P) -> Result<Config> {
let mut buffer = String::new();
File::open(config_file)
.chain_err(|| "Unable to open the configuration file")?
.read_to_string(&mut buffer)
.chain_err(|| "Couldn't read the file")?;
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Config::from_str(&buffer)
}
/// Updates the `Config` from the available environment variables.
///
/// Variables starting with `MDBOOK_` are used for configuration. The key is
/// created by removing the `MDBOOK_` prefix and turning the resulting
/// string into `kebab-case`. Double underscores (`__`) separate nested
/// keys, while a single underscore (`_`) is replaced with a dash (`-`).
///
/// For example:
///
/// - `MDBOOK_foo` -> `foo`
/// - `MDBOOK_FOO` -> `foo`
/// - `MDBOOK_FOO__BAR` -> `foo.bar`
/// - `MDBOOK_FOO_BAR` -> `foo-bar`
/// - `MDBOOK_FOO_bar__baz` -> `foo-bar.baz`
///
/// So by setting the `MDBOOK_BOOK__TITLE` environment variable you can
/// override the book's title without needing to touch your `book.toml`.
///
/// > **Note:** To facilitate setting more complex config items, the value
/// > of an environment variable is first parsed as JSON, falling back to a
/// > string if the parse fails.
/// >
/// > This means, if you so desired, you could override all book metadata
/// > when building the book with something like
/// >
/// > ```text
/// > $ export MDBOOK_BOOK="{'title': 'My Awesome Book', authors: ['Michael-F-Bryan']}"
/// > $ mdbook build
/// > ```
///
/// The latter case may be useful in situations where `mdbook` is invoked
/// from a script or CI, where it sometimes isn't possible to update the
/// `book.toml` before building.
pub fn update_from_env(&mut self) {
debug!("Updating the config from environment variables");
let overrides = env::vars().filter_map(|(key, value)| match parse_env(&key) {
Some(index) => Some((index, value)),
None => None,
});
for (key, value) in overrides {
trace!("{} => {}", key, value);
let parsed_value = serde_json::from_str(&value)
.unwrap_or_else(|_| serde_json::Value::String(value.to_string()));
self.set(key, parsed_value).expect("unreachable");
}
}
/// Fetch an arbitrary item from the `Config` as a `toml::Value`.
///
/// You can use dotted indices to access nested items (e.g.
/// `output.html.playpen` will fetch the "playpen" out of the html output
/// table).
pub fn get(&self, key: &str) -> Option<&Value> {
match self.rest.read(key) {
Ok(inner) => inner,
Err(_) => None,
}
}
/// Fetch a value from the `Config` so you can mutate it.
pub fn get_mut<'a>(&'a mut self, key: &str) -> Option<&'a mut Value> {
match self.rest.read_mut(key) {
Ok(inner) => inner,
Err(_) => None,
}
}
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/// Convenience method for getting the html renderer's configuration.
///
/// # Note
///
/// This is for compatibility only. It will be removed completely once the
/// HTML renderer is refactored to be less coupled to `mdbook` internals.
#[doc(hidden)]
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pub fn html_config(&self) -> Option<HtmlConfig> {
self.get_deserialized("output.html").ok()
}
/// Convenience function to fetch a value from the config and deserialize it
/// into some arbitrary type.
pub fn get_deserialized<'de, T: Deserialize<'de>, S: AsRef<str>>(&self, name: S) -> Result<T> {
let name = name.as_ref();
if let Some(value) = self.get(name) {
value
.clone()
.try_into()
.chain_err(|| "Couldn't deserialize the value")
} else {
bail!("Key not found, {:?}", name)
}
}
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/// Set a config key, clobbering any existing values along the way.
///
/// The only way this can fail is if we can't serialize `value` into a
/// `toml::Value`.
pub fn set<S: Serialize, I: AsRef<str>>(&mut self, index: I, value: S) -> Result<()> {
let index = index.as_ref();
let value =
Value::try_from(value).chain_err(|| "Unable to represent the item as a JSON Value")?;
if index.starts_with("book.") {
self.book.update_value(&index[5..], value);
} else if index.starts_with("build.") {
self.build.update_value(&index[6..], value);
} else {
self.rest.insert(index, value)?;
}
Ok(())
}
fn from_legacy(mut table: Value) -> Config {
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let mut cfg = Config::default();
// we use a macro here instead of a normal loop because the $out
// variable can be different types. This way we can make type inference
// figure out what try_into() deserializes to.
macro_rules! get_and_insert {
($table:expr, $key:expr => $out:expr) => {
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let got = $table
.as_table_mut()
.and_then(|t| t.remove($key))
.and_then(|v| v.try_into().ok());
if let Some(value) = got {
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$out = value;
}
};
}
get_and_insert!(table, "title" => cfg.book.title);
get_and_insert!(table, "authors" => cfg.book.authors);
get_and_insert!(table, "source" => cfg.book.src);
get_and_insert!(table, "description" => cfg.book.description);
if let Ok(Some(dest)) = table.delete("output.html.destination") {
if let Ok(destination) = dest.try_into() {
cfg.build.build_dir = destination;
}
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}
cfg.rest = table;
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cfg
}
}
impl Default for Config {
fn default() -> Config {
Config {
book: BookConfig::default(),
build: BuildConfig::default(),
rest: Value::Table(Table::default()),
}
}
}
impl<'de> Deserialize<'de> for Config {
fn deserialize<D: Deserializer<'de>>(de: D) -> ::std::result::Result<Self, D::Error> {
let raw = Value::deserialize(de)?;
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if is_legacy_format(&raw) {
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warn!("It looks like you are using the legacy book.toml format.");
warn!("We'll parse it for now, but you should probably convert to the new format.");
warn!("See the mdbook documentation for more details, although as a rule of thumb");
warn!("just move all top level configuration entries like `title`, `author` and");
warn!("`description` under a table called `[book]`, move the `destination` entry");
warn!("from `[output.html]`, renamed to `build-dir`, under a table called");
warn!("`[build]`, and it should all work.");
warn!("Documentation: http://rust-lang-nursery.github.io/mdBook/format/config.html");
return Ok(Config::from_legacy(raw));
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}
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let mut table = match raw {
Value::Table(t) => t,
_ => {
use serde::de::Error;
return Err(D::Error::custom(
"A config file should always be a toml table",
));
}
};
let book: BookConfig = table
.remove("book")
.and_then(|value| value.try_into().ok())
.unwrap_or_default();
let build: BuildConfig = table
.remove("build")
.and_then(|value| value.try_into().ok())
.unwrap_or_default();
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Ok(Config {
book: book,
build: build,
rest: Value::Table(table),
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})
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}
}
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impl Serialize for Config {
fn serialize<S: Serializer>(&self, s: S) -> ::std::result::Result<S::Ok, S::Error> {
use serde::ser::Error;
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let mut table = self.rest.clone();
let book_config = match Value::try_from(self.book.clone()) {
Ok(cfg) => cfg,
Err(_) => {
return Err(S::Error::custom("Unable to serialize the BookConfig"));
}
};
table.insert("book", book_config).expect("unreachable");
table.serialize(s)
}
}
fn parse_env(key: &str) -> Option<String> {
const PREFIX: &str = "MDBOOK_";
if key.starts_with(PREFIX) {
let key = &key[PREFIX.len()..];
Some(key.to_lowercase().replace("__", ".").replace("_", "-"))
} else {
None
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}
}
fn is_legacy_format(table: &Value) -> bool {
let legacy_items = [
"title",
"authors",
"source",
"description",
"output.html.destination",
];
for item in &legacy_items {
if let Ok(Some(_)) = table.read(item) {
return true;
}
}
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false
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}
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/// Configuration options which are specific to the book and required for
/// loading it from disk.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
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#[serde(default, rename_all = "kebab-case")]
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pub struct BookConfig {
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/// The book's title.
pub title: Option<String>,
/// The book's authors.
pub authors: Vec<String>,
/// An optional description for the book.
pub description: Option<String>,
/// Location of the book source relative to the book's root directory.
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pub src: PathBuf,
/// Does this book support more than one language?
pub multilingual: bool,
}
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impl Default for BookConfig {
fn default() -> BookConfig {
BookConfig {
title: None,
authors: Vec::new(),
description: None,
src: PathBuf::from("src"),
multilingual: false,
}
}
}
/// Configuration for the build procedure.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(default, rename_all = "kebab-case")]
pub struct BuildConfig {
/// Where to put built artefacts relative to the book's root directory.
pub build_dir: PathBuf,
/// Should non-existent markdown files specified in `SETTINGS.md` be created
/// if they don't exist?
pub create_missing: bool,
/// Which preprocessors should be applied
pub preprocess: Option<Vec<String>>,
}
impl Default for BuildConfig {
fn default() -> BuildConfig {
BuildConfig {
build_dir: PathBuf::from("book"),
create_missing: true,
preprocess: None,
}
}
}
/// Configuration for the HTML renderer.
#[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
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#[serde(default, rename_all = "kebab-case")]
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pub struct HtmlConfig {
/// The theme directory, if specified.
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pub theme: Option<PathBuf>,
/// Use "smart quotes" instead of the usual `"` character.
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pub curly_quotes: bool,
/// Should mathjax be enabled?
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pub mathjax_support: bool,
/// An optional google analytics code.
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pub google_analytics: Option<String>,
/// Additional CSS stylesheets to include in the rendered page's `<head>`.
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pub additional_css: Vec<PathBuf>,
/// Additional JS scripts to include at the bottom of the rendered page's
/// `<body>`.
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pub additional_js: Vec<PathBuf>,
/// Playpen settings.
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pub playpen: Playpen,
/// This is used as a bit of a workaround for the `mdbook serve` command.
/// Basically, because you set the websocket port from the command line, the
/// `mdbook serve` command needs a way to let the HTML renderer know where
/// to point livereloading at, if it has been enabled.
///
/// This config item *should not be edited* by the end user.
#[doc(hidden)]
pub livereload_url: Option<String>,
/// Should section labels be rendered?
pub no_section_label: bool,
/// Search settings. If `None`, the default will be used.
pub search: Option<Search>,
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}
impl HtmlConfig {
/// Returns the directory of theme from the provided root directory. If the
/// directory is not present it will append the default directory of "theme"
pub fn theme_dir(&self, root: &PathBuf) -> PathBuf {
match self.theme {
Some(ref d) => root.join(d),
None => root.join("theme"),
}
}
}
/// Configuration for tweaking how the the HTML renderer handles the playpen.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(default, rename_all = "kebab-case")]
pub struct Playpen {
/// Should playpen snippets be editable? Default: `false`.
pub editable: bool,
/// Copy JavaScript files for the editor to the output directory?
/// Default: `true`.
pub copy_js: bool,
}
impl Default for Playpen {
fn default() -> Playpen {
Playpen {
editable: false,
copy_js: true,
}
}
}
/// Configuration of the search functionality of the HTML renderer.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(default, rename_all = "kebab-case")]
pub struct Search {
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/// Enable the search feature. Default: `true`.
pub enable: bool,
/// Maximum number of visible results. Default: `30`.
pub limit_results: u32,
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/// The number of words used for a search result teaser. Default: `30`.
pub teaser_word_count: u32,
/// Define the logical link between multiple search words.
/// If true, all search words must appear in each result. Default: `true`.
pub use_boolean_and: bool,
/// Boost factor for the search result score if a search word appears in the header.
/// Default: `2`.
pub boost_title: u8,
/// Boost factor for the search result score if a search word appears in the hierarchy.
/// The hierarchy contains all titles of the parent documents and all parent headings.
/// Default: `1`.
pub boost_hierarchy: u8,
/// Boost factor for the search result score if a search word appears in the text.
/// Default: `1`.
pub boost_paragraph: u8,
/// True if the searchword `micro` should match `microwave`. Default: `true`.
pub expand: bool,
/// Documents are split into smaller parts, seperated by headings. This defines, until which
/// level of heading documents should be split. Default: `3`. (`### This is a level 3 heading`)
pub heading_split_level: u8,
/// Copy JavaScript files for the search functionality to the output directory?
/// Default: `true`.
pub copy_js: bool,
}
impl Default for Search {
fn default() -> Search {
// Please update the documentation of `Search` when changing values!
Search {
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enable: true,
limit_results: 30,
teaser_word_count: 30,
use_boolean_and: false,
boost_title: 2,
boost_hierarchy: 1,
boost_paragraph: 1,
expand: true,
heading_split_level: 3,
copy_js: true,
}
}
}
/// Allows you to "update" any arbitrary field in a struct by round-tripping via
/// a `toml::Value`.
///
/// This is definitely not the most performant way to do things, which means you
/// should probably keep it away from tight loops...
trait Updateable<'de>: Serialize + Deserialize<'de> {
fn update_value<S: Serialize>(&mut self, key: &str, value: S) {
let mut raw = Value::try_from(&self).expect("unreachable");
{
if let Ok(value) = Value::try_from(value) {
let _ = raw.insert(key, value);
} else {
return;
}
}
if let Ok(updated) = raw.try_into() {
*self = updated;
}
}
}
impl<'de, T> Updateable<'de> for T
where
T: Serialize + Deserialize<'de>,
{
}
#[cfg(test)]
mod tests {
use super::*;
const COMPLEX_CONFIG: &'static str = r#"
[book]
title = "Some Book"
authors = ["Michael-F-Bryan <michaelfbryan@gmail.com>"]
description = "A completely useless book"
multilingual = true
src = "source"
[build]
build-dir = "outputs"
create-missing = false
preprocess = ["first_preprocessor", "second_preprocessor"]
[output.html]
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theme = "./themedir"
curly-quotes = true
google-analytics = "123456"
additional-css = ["./foo/bar/baz.css"]
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[output.html.playpen]
editable = true
editor = "ace"
"#;
#[test]
fn load_a_complex_config_file() {
let src = COMPLEX_CONFIG;
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let book_should_be = BookConfig {
title: Some(String::from("Some Book")),
authors: vec![String::from("Michael-F-Bryan <michaelfbryan@gmail.com>")],
description: Some(String::from("A completely useless book")),
multilingual: true,
src: PathBuf::from("source"),
..Default::default()
};
let build_should_be = BuildConfig {
build_dir: PathBuf::from("outputs"),
create_missing: false,
preprocess: Some(vec![
"first_preprocessor".to_string(),
"second_preprocessor".to_string(),
]),
};
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let playpen_should_be = Playpen {
editable: true,
copy_js: true,
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};
let html_should_be = HtmlConfig {
curly_quotes: true,
google_analytics: Some(String::from("123456")),
additional_css: vec![PathBuf::from("./foo/bar/baz.css")],
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theme: Some(PathBuf::from("./themedir")),
playpen: playpen_should_be,
..Default::default()
};
let got = Config::from_str(src).unwrap();
assert_eq!(got.book, book_should_be);
assert_eq!(got.build, build_should_be);
assert_eq!(got.html_config().unwrap(), html_should_be);
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}
#[test]
fn load_arbitrary_output_type() {
#[derive(Debug, Deserialize, PartialEq)]
struct RandomOutput {
foo: u32,
bar: String,
baz: Vec<bool>,
}
let src = r#"
[output.random]
foo = 5
bar = "Hello World"
baz = [true, true, false]
"#;
let should_be = RandomOutput {
foo: 5,
bar: String::from("Hello World"),
baz: vec![true, true, false],
};
let cfg = Config::from_str(src).unwrap();
let got: RandomOutput = cfg.get_deserialized("output.random").unwrap();
assert_eq!(got, should_be);
let baz: Vec<bool> = cfg.get_deserialized("output.random.baz").unwrap();
let baz_should_be = vec![true, true, false];
assert_eq!(baz, baz_should_be);
}
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#[test]
fn mutate_some_stuff() {
// really this is just a sanity check to make sure the borrow checker
// is happy...
let src = COMPLEX_CONFIG;
let mut config = Config::from_str(src).unwrap();
let key = "output.html.playpen.editable";
assert_eq!(config.get(key).unwrap(), &Value::Boolean(true));
*config.get_mut(key).unwrap() = Value::Boolean(false);
assert_eq!(config.get(key).unwrap(), &Value::Boolean(false));
}
/// The config file format has slightly changed (metadata stuff is now under
/// the `book` table instead of being at the top level) so we're adding a
/// **temporary** compatibility check. You should be able to still load the
/// old format, emitting a warning.
#[test]
fn can_still_load_the_previous_format() {
let src = r#"
title = "mdBook Documentation"
description = "Create book from markdown files. Like Gitbook but implemented in Rust"
authors = ["Mathieu David"]
source = "./source"
[output.html]
destination = "my-book" # the output files will be generated in `root/my-book` instead of `root/book`
theme = "my-theme"
curly-quotes = true
google-analytics = "123456"
additional-css = ["custom.css", "custom2.css"]
additional-js = ["custom.js"]
"#;
let book_should_be = BookConfig {
title: Some(String::from("mdBook Documentation")),
description: Some(String::from(
"Create book from markdown files. Like Gitbook but implemented in Rust",
)),
authors: vec![String::from("Mathieu David")],
src: PathBuf::from("./source"),
..Default::default()
};
let build_should_be = BuildConfig {
build_dir: PathBuf::from("my-book"),
create_missing: true,
preprocess: None,
};
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let html_should_be = HtmlConfig {
theme: Some(PathBuf::from("my-theme")),
curly_quotes: true,
google_analytics: Some(String::from("123456")),
additional_css: vec![PathBuf::from("custom.css"), PathBuf::from("custom2.css")],
additional_js: vec![PathBuf::from("custom.js")],
..Default::default()
};
let got = Config::from_str(src).unwrap();
assert_eq!(got.book, book_should_be);
assert_eq!(got.build, build_should_be);
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assert_eq!(got.html_config().unwrap(), html_should_be);
}
#[test]
fn set_a_config_item() {
let mut cfg = Config::default();
let key = "foo.bar.baz";
let value = "Something Interesting";
assert!(cfg.get(key).is_none());
cfg.set(key, value).unwrap();
let got: String = cfg.get_deserialized(key).unwrap();
assert_eq!(got, value);
}
#[test]
fn parse_env_vars() {
let inputs = vec![
("FOO", None),
("MDBOOK_foo", Some("foo")),
("MDBOOK_FOO__bar__baz", Some("foo.bar.baz")),
("MDBOOK_FOO_bar__baz", Some("foo-bar.baz")),
];
for (src, should_be) in inputs {
let got = parse_env(src);
let should_be = should_be.map(|s| s.to_string());
assert_eq!(got, should_be);
}
}
fn encode_env_var(key: &str) -> String {
format!(
"MDBOOK_{}",
key.to_uppercase().replace('.', "__").replace("-", "_")
)
}
#[test]
fn update_config_using_env_var() {
let mut cfg = Config::default();
let key = "foo.bar";
let value = "baz";
assert!(cfg.get(key).is_none());
let encoded_key = encode_env_var(key);
env::set_var(encoded_key, value);
cfg.update_from_env();
assert_eq!(cfg.get_deserialized::<String, _>(key).unwrap(), value);
}
#[test]
fn update_config_using_env_var_and_complex_value() {
let mut cfg = Config::default();
let key = "foo-bar.baz";
let value = json!({"array": [1, 2, 3], "number": 3.14});
let value_str = serde_json::to_string(&value).unwrap();
assert!(cfg.get(key).is_none());
let encoded_key = encode_env_var(key);
env::set_var(encoded_key, value_str);
cfg.update_from_env();
assert_eq!(
cfg.get_deserialized::<serde_json::Value, _>(key).unwrap(),
value
);
}
#[test]
fn update_book_title_via_env() {
let mut cfg = Config::default();
let should_be = "Something else".to_string();
assert_ne!(cfg.book.title, Some(should_be.clone()));
env::set_var("MDBOOK_BOOK__TITLE", &should_be);
cfg.update_from_env();
assert_eq!(cfg.book.title, Some(should_be));
}
}