Merge pull request rust-lang#361 from Michael-F-Bryan/error-chain

Add error-chain throughout the codebase

.travis.yml

@@ -28,6 +28,13 @@ matrix:
  - nodejs
  - os: linux
  env: TARGET=x86_64-unknown-linux-musl CHANNEL=stable
+ dist: trusty
+ addons:
+ apt:
+ packages: &musl_packages
+ - musl
+ - musl-dev
+ - musl-tools
  # Beta channel
  - os: osx
  env: TARGET=i686-apple-darwin CHANNEL=beta
@@ -42,6 +49,13 @@ matrix:
  env: TARGET=x86_64-unknown-linux-gnu CHANNEL=beta
  - os: linux
  env: TARGET=x86_64-unknown-linux-musl CHANNEL=beta
+ dist: trusty
+ addons:
+ apt:
+ packages: &musl_packages
+ - musl
+ - musl-dev
+ - musl-tools
  # Nightly channel
  - os: osx
  env: TARGET=i686-apple-darwin CHANNEL=nightly
@@ -56,6 +70,13 @@ matrix:
  env: TARGET=x86_64-unknown-linux-gnu CHANNEL=nightly
  - os: linux
  env: TARGET=x86_64-unknown-linux-musl CHANNEL=nightly
+ dist: trusty
+ addons:
+ apt:
+ packages: &musl_packages
+ - musl
+ - musl-dev
+ - musl-tools
 
 install:
  - export PATH="$PATH:$HOME/.cargo/bin"

Cargo.toml

@@ -19,6 +19,7 @@ clap = "2.24"
 handlebars = "0.27"
 serde = "1.0"
 serde_derive = "1.0"
+error-chain = "0.10.0"
 serde_json = "1.0"
 pulldown-cmark = "0.0.14"
 log = "0.3"

src/bin/mdbook.rs

@@ -14,10 +14,10 @@ extern crate time;
 extern crate crossbeam;
 
 use std::env;
-use std::error::Error;
 use std::ffi::OsStr;
 use std::io::{self, Write};
 use std::path::{Path, PathBuf};
+use mdbook::errors::*;
 
 use clap::{App, ArgMatches, SubCommand, AppSettings};
 
@@ -110,7 +110,7 @@ fn confirm() -> bool {
 
 
 // Init command implementation
-fn init(args: &ArgMatches) -> Result<(), Box<Error>> {
+fn init(args: &ArgMatches) -> Result<()> {
 
  let book_dir = get_book_dir(args);
  let mut book = MDBook::new(&book_dir);
@@ -163,7 +163,7 @@ fn init(args: &ArgMatches) -> Result<(), Box<Error>> {
 
 
 // Build command implementation
-fn build(args: &ArgMatches) -> Result<(), Box<Error>> {
+fn build(args: &ArgMatches) -> Result<()> {
  let book_dir = get_book_dir(args);
  let book = MDBook::new(&book_dir).read_config()?;
 
@@ -194,7 +194,7 @@ fn build(args: &ArgMatches) -> Result<(), Box<Error>> {
 
 // Watch command implementation
 #[cfg(feature = "watch")]
-fn watch(args: &ArgMatches) -> Result<(), Box<Error>> {
+fn watch(args: &ArgMatches) -> Result<()> {
  let book_dir = get_book_dir(args);
  let book = MDBook::new(&book_dir).read_config()?;
 
@@ -233,7 +233,7 @@ mod serve {
 
  use std;
  use std::path::Path;
- use std::error::Error;
+ use mdbook::errors::*;
  use self::iron::{Iron, AfterMiddleware, IronResult, IronError, Request, Response, status, Set, Chain};
  use clap::ArgMatches;
  use mdbook::MDBook;
@@ -253,7 +253,7 @@ mod serve {
  }
 
  // Watch command implementation
- pub fn serve(args: &ArgMatches) -> Result<(), Box<Error>> {
+ pub fn serve(args: &ArgMatches) -> Result<()> {
  const RELOAD_COMMAND: &'static str = "reload";
 
  let book_dir = get_book_dir(args);
@@ -334,7 +334,7 @@ mod serve {
  }
 }
 
-fn test(args: &ArgMatches) -> Result<(), Box<Error>> {
+fn test(args: &ArgMatches) -> Result<()> {
  let book_dir = get_book_dir(args);
  let mut book = MDBook::new(&book_dir).read_config()?;
 

src/book/bookitem.rs

@@ -2,6 +2,7 @@ use serde::{Serialize, Serializer};
 use serde::ser::SerializeStruct;
 use std::path::PathBuf;
 
+
 #[derive(Debug, Clone)]
 pub enum BookItem {
  Chapter(String, Chapter), // String = section
@@ -37,7 +38,7 @@ impl Chapter {
 
 
 impl Serialize for Chapter {
- fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ fn serialize<S>(&self, serializer: S) -> ::std::result::Result<S::Ok, S::Error>
  where S: Serializer
  {
  let mut struct_ = serializer.serialize_struct("Chapter", 2)?;

src/book/mod.rs

@@ -4,14 +4,12 @@ pub use self::bookitem::{BookItem, BookItems};
 
 use std::path::{Path, PathBuf};
 use std::fs::{self, File};
-use std::error::Error;
-use std::io;
 use std::io::{Read, Write};
-use std::io::ErrorKind;
 use std::process::Command;
 
 use {theme, parse, utils};
 use renderer::{Renderer, HtmlHandlebars};
+use errors::*;
 
 use config::BookConfig;
 use config::tomlconfig::TomlConfig;
@@ -129,7 +127,7 @@ impl MDBook {
  /// and adds a `SUMMARY.md` and a
  /// `chapter_1.md` to the source directory.
 
- pub fn init(&mut self) -> Result<(), Box<Error>> {
+ pub fn init(&mut self) -> Result<()> {
 
  debug!("[fn]: init");
 
@@ -239,7 +237,7 @@ impl MDBook {
  /// method of the current renderer.
  ///
  /// It is the renderer who generates all the output files.
- pub fn build(&mut self) -> Result<(), Box<Error>> {
+ pub fn build(&mut self) -> Result<()> {
  debug!("[fn]: build");
 
  self.init()?;
@@ -249,17 +247,15 @@ impl MDBook {
  utils::fs::remove_dir_content(htmlconfig.get_destination())?;
  }
 
- self.renderer.render(&self)?;
-
- Ok(())
+ self.renderer.render(&self)
  }
 
 
  pub fn get_gitignore(&self) -> PathBuf {
  self.config.get_root().join(".gitignore")
  }
 
- pub fn copy_theme(&self) -> Result<(), Box<Error>> {
+ pub fn copy_theme(&self) -> Result<()> {
  debug!("[fn]: copy_theme");
 
  if let Some(htmlconfig) = self.config.get_html_config() {
@@ -298,24 +294,22 @@ impl MDBook {
  Ok(())
  }
 
- pub fn write_file<P: AsRef<Path>>(&self, filename: P, content: &[u8]) -> Result<(), Box<Error>> {
+ pub fn write_file<P: AsRef<Path>>(&self, filename: P, content: &[u8]) -> Result<()> {
  let path = self.get_destination()
  .ok_or(String::from("HtmlConfig not set, could not find a destination"))?
  .join(filename);
 
- utils::fs::create_file(&path)
- .and_then(|mut file| file.write_all(content))
- .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("Could not create {}: {}", path.display(), e)))?;
-
- Ok(())
+ utils::fs::create_file(&path)?
+ .write_all(content)
+ .map_err(|e| e.into())
  }
 
  /// Parses the `book.json` file (if it exists) to extract
  /// the configuration parameters.
  /// The `book.json` file should be in the root directory of the book.
  /// The root directory is the one specified when creating a new `MDBook`
 
- pub fn read_config(mut self) -> Result<Self, Box<Error>> {
+ pub fn read_config(mut self) -> Result<Self> {
 
  let toml = self.get_root().join("book.toml");
  let json = self.get_root().join("book.json");
@@ -369,9 +363,9 @@ impl MDBook {
  self
  }
 
- pub fn test(&mut self) -> Result<(), Box<Error>> {
+ pub fn test(&mut self) -> Result<()> {
  // read in the chapters
- self.parse_summary()?;
+ self.parse_summary().chain_err(|| "Couldn't parse summary")?;
  for item in self.iter() {
 
  if let BookItem::Chapter(_, ref ch) = *item {
@@ -381,15 +375,10 @@ impl MDBook {
 
  println!("[*]: Testing file: {:?}", path);
 
- let output_result = Command::new("rustdoc").arg(&path).arg("--test").output();
- let output = output_result?;
+ let output = Command::new("rustdoc").arg(&path).arg("--test").output()?;
 
  if !output.status.success() {
- return Err(Box::new(io::Error::new(ErrorKind::Other,
- format!("{}\n{}",
- String::from_utf8_lossy(&output.stdout),
- String::from_utf8_lossy(&output.stderr)))) as
- Box<Error>);
+ bail!(ErrorKind::Subprocess("Rustdoc returned an error".to_string(), output));
  }
  }
  }
@@ -556,7 +545,7 @@ impl MDBook {
  }
 
  // Construct book
- fn parse_summary(&mut self) -> Result<(), Box<Error>> {
+ fn parse_summary(&mut self) -> Result<()> {
  // When append becomes stable, use self.content.append() ...
  self.content = parse::construct_bookitems(&self.get_source().join("SUMMARY.md"))?;
  Ok(())

src/config/jsonconfig.rs

@@ -1,5 +1,6 @@
 extern crate serde_json;
 use std::path::PathBuf;
+use errors::*;
 
 /// The JSON configuration is **deprecated** and will be removed in the near future.
 /// Please migrate to the TOML configuration.
@@ -32,9 +33,9 @@ pub struct JsonConfig {
 /// assert_eq!(config.dest, Some(PathBuf::from("htmlbook")));
 /// ```
 impl JsonConfig {
- pub fn from_json(input: &str) -> Result<Self, String> {
+ pub fn from_json(input: &str) -> Result<Self> {
  let config: JsonConfig = serde_json::from_str(input)
- .map_err(|e| format!("Could not parse JSON: {}", e))?;
+ .chain_err(|| format!("Could not parse JSON"))?;
 
  return Ok(config);
  }

src/config/tomlconfig.rs

@@ -1,5 +1,6 @@
 extern crate toml;
 use std::path::PathBuf;
+use errors::*;
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 pub struct TomlConfig {
@@ -44,9 +45,9 @@ pub struct TomlHtmlConfig {
 /// assert_eq!(config.output.unwrap().html.unwrap().destination, Some(PathBuf::from("htmlbook")));
 /// ```
 impl TomlConfig {
- pub fn from_toml(input: &str) -> Result<Self, String> {
+ pub fn from_toml(input: &str) -> Result<Self> {
  let config: TomlConfig = toml::from_str(input)
- .map_err(|e| format!("Could not parse TOML: {}", e))?;
+ .chain_err(|| "Could not parse TOML")?;
 
  return Ok(config);
  }

src/lib.rs

@@ -69,10 +69,13 @@
 //!
 //! Make sure to take a look at it.
 
+#[macro_use]
+extern crate error_chain;
 #[macro_use]
 extern crate serde_derive;
 extern crate serde;
-#[macro_use] extern crate serde_json;
+#[macro_use] 
+extern crate serde_json;
 
 extern crate handlebars;
 extern crate pulldown_cmark;
@@ -90,3 +93,21 @@ pub mod utils;
 pub use book::MDBook;
 pub use book::BookItem;
 pub use renderer::Renderer;
+
+/// The error types used through out this crate.
+pub mod errors {
+ error_chain!{
+ foreign_links {
+ Io(::std::io::Error);
+ HandlebarsRender(::handlebars::RenderError);
+ HandlebarsTemplate(::handlebars::TemplateError);
+ Utf8(::std::string::FromUtf8Error);
+ }
+
+ errors {
+ Subprocess(message: String, output: ::std::process::Output) {
+ description("A subprocess failed")
+ }
+ }
+ }
+}