Merge pull request #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()?;
@@ -249,9 +247,7 @@ impl MDBook {
             utils::fs::remove_dir_content(htmlconfig.get_destination())?;
         }
 
-        self.renderer.render(&self)?;
+        self.renderer.render(&self)
-
-        Ok(())
     }
 
 
@@ -259,7 +255,7 @@ impl MDBook {
         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() {
@@ -298,16 +294,14 @@ 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)
+        utils::fs::create_file(&path)?
-            .and_then(|mut file| file.write_all(content))
+            .write_all(content)
-            .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("Could not create {}: {}", path.display(), e)))?;
+            .map_err(|e| e.into())
-
-        Ok(())
     }
 
     /// Parses the `book.json` file (if it exists) to extract
@@ -315,7 +309,7 @@ impl MDBook {
     /// 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 = Command::new("rustdoc").arg(&path).arg("--test").output()?;
-                    let output = output_result?;
 
                     if !output.status.success() {
-                        return Err(Box::new(io::Error::new(ErrorKind::Other,
+                        bail!(ErrorKind::Subprocess("Rustdoc returned an error".to_string(), output));
-                                                           format!("{}\n{}",
-                                                                   String::from_utf8_lossy(&output.stdout),
-                                                                   String::from_utf8_lossy(&output.stderr)))) as
-                                   Box<Error>);
                     }
                 }
             }
@@ -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")
+            }
+        }
+    }
+}

src/renderer/html_handlebars/hbs_renderer.rs

@@ -4,12 +4,12 @@ use book::MDBook;
 use book::bookitem::{BookItem, Chapter};
 use utils;
 use theme::{self, Theme};
+use errors::*;
 use regex::{Regex, Captures};
 
 use std::ascii::AsciiExt;
 use std::path::{Path, PathBuf};
 use std::fs::{self, File};
-use std::error::Error;
 use std::io::{self, Read};
 use std::collections::BTreeMap;
 use std::collections::HashMap;
@@ -28,7 +28,7 @@ impl HtmlHandlebars {
     }
 
     fn render_item(&self, item: &BookItem, mut ctx: RenderItemContext, print_content: &mut String)
-        -> Result<(), Box<Error>> {
+        -> Result<()> {
         // FIXME: This should be made DRY-er and rely less on mutable state
         match *item {
             BookItem::Chapter(_, ref ch) |
@@ -88,7 +88,7 @@ impl HtmlHandlebars {
     }
 
     /// Create an index.html from the first element in SUMMARY.md
-    fn render_index(&self, book: &MDBook, ch: &Chapter, destination: &Path) -> Result<(), Box<Error>> {
+    fn render_index(&self, book: &MDBook, ch: &Chapter, destination: &Path) -> Result<()> {
         debug!("[*]: index.html");
 
         let mut content = String::new();
@@ -129,7 +129,7 @@ impl HtmlHandlebars {
         rendered
     }
 
-    fn copy_static_files(&self, book: &MDBook, theme: &Theme) -> Result<(), Box<Error>> {
+    fn copy_static_files(&self, book: &MDBook, theme: &Theme) -> Result<()> {
         book.write_file("book.js", &theme.js)?;
         book.write_file("book.css", &theme.css)?;
         book.write_file("favicon.png", &theme.favicon)?;
@@ -180,7 +180,7 @@ impl HtmlHandlebars {
 
     /// Helper function to write a file to the build directory, normalizing 
     /// the path to be relative to the book root.
-    fn write_custom_file(&self, custom_file: &Path, book: &MDBook) -> Result<(), Box<Error>> {
+    fn write_custom_file(&self, custom_file: &Path, book: &MDBook) -> Result<()> {
         let mut data = Vec::new();
         let mut f = File::open(custom_file)?;
         f.read_to_end(&mut data)?;
@@ -216,7 +216,7 @@ impl HtmlHandlebars {
 
     /// Copy across any additional CSS and JavaScript files which the book
     /// has been configured to use.
-    fn copy_additional_css_and_js(&self, book: &MDBook) -> Result<(), Box<Error>> {
+    fn copy_additional_css_and_js(&self, book: &MDBook) -> Result<()> {
         let custom_files = book.get_additional_css().iter().chain(
             book.get_additional_js()
                 .iter(),
@@ -232,7 +232,7 @@ impl HtmlHandlebars {
 
 
 impl Renderer for HtmlHandlebars {
-    fn render(&self, book: &MDBook) -> Result<(), Box<Error>> {
+    fn render(&self, book: &MDBook) -> Result<()> {
         debug!("[fn]: render");
         let mut handlebars = Handlebars::new();
 
@@ -258,9 +258,7 @@ impl Renderer for HtmlHandlebars {
 
         debug!("[*]: Check if destination directory exists");
         if fs::create_dir_all(&destination).is_err() {
-            return Err(Box::new(
+            bail!("Unexpected error when constructing destination path");
-                io::Error::new(io::ErrorKind::Other, "Unexpected error when constructing destination path"),
-            ));
         }
 
         for (i, item) in book.iter().enumerate() {
@@ -301,7 +299,7 @@ impl Renderer for HtmlHandlebars {
     }
 }
 
-fn make_data(book: &MDBook) -> Result<serde_json::Map<String, serde_json::Value>, Box<Error>> {
+fn make_data(book: &MDBook) -> Result<serde_json::Map<String, serde_json::Value>> {
     debug!("[fn]: make_data");
 
     let mut data = serde_json::Map::new();

src/renderer/mod.rs

@@ -2,8 +2,8 @@ pub use self::html_handlebars::HtmlHandlebars;
 
 mod html_handlebars;
 
-use std::error::Error;
+use errors::*;
 
 pub trait Renderer {
-    fn render(&self, book: &::book::MDBook) -> Result<(), Box<Error>>;
+    fn render(&self, book: &::book::MDBook) -> Result<()>;
 }

src/utils/fs.rs

@@ -1,16 +1,16 @@
 use std::path::{Path, PathBuf, Component};
-use std::error::Error;
+use errors::*;
-use std::io::{self, Read};
+use std::io::Read;
 use std::fs::{self, File};
 
 /// Takes a path to a file and try to read the file into a String
 
-pub fn file_to_string(path: &Path) -> Result<String, Box<Error>> {
+pub fn file_to_string(path: &Path) -> Result<String> {
     let mut file = match File::open(path) {
         Ok(f) => f,
         Err(e) => {
             debug!("[*]: Failed to open {:?}", path);
-            return Err(Box::new(e));
+            bail!(e);
         },
     };
 
@@ -18,7 +18,7 @@ pub fn file_to_string(path: &Path) -> Result<String, Box<Error>> {
 
     if let Err(e) = file.read_to_string(&mut content) {
         debug!("[*]: Failed to read {:?}", path);
-        return Err(Box::new(e));
+        bail!(e);
     }
 
     Ok(content)
@@ -72,7 +72,7 @@ pub fn path_to_root<P: Into<PathBuf>>(path: P) -> String {
 /// it checks every directory in the path to see if it exists,
 /// and if it does not it will be created.
 
-pub fn create_file(path: &Path) -> io::Result<File> {
+pub fn create_file(path: &Path) -> Result<File> {
     debug!("[fn]: create_file");
 
     // Construct path
@@ -83,12 +83,12 @@ pub fn create_file(path: &Path) -> io::Result<File> {
     }
 
     debug!("[*]: Create file: {:?}", path);
-    File::create(path)
+    File::create(path).map_err(|e| e.into())
 }
 
 /// Removes all the content of a directory but not the directory itself
 
-pub fn remove_dir_content(dir: &Path) -> Result<(), Box<Error>> {
+pub fn remove_dir_content(dir: &Path) -> Result<()> {
     for item in fs::read_dir(dir)? {
         if let Ok(item) = item {
             let item = item.path();
@@ -108,7 +108,7 @@ pub fn remove_dir_content(dir: &Path) -> Result<(), Box<Error>> {
 /// with the extensions given in the `ext_blacklist` array
 
 pub fn copy_files_except_ext(from: &Path, to: &Path, recursive: bool, ext_blacklist: &[&str])
-                             -> Result<(), Box<Error>> {
+                             -> Result<()> {
     debug!("[fn] copy_files_except_ext");
     // Check that from and to are different
     if from == to {