Merge pull request #757 from mattico/improve-argparse

Improve command-line argument parsing

15 files changed, 237 insertions, 118 deletions

diff --git a/book-example/src/cli/build.md b/book-example/src/cli/build.md
index 9da2eca1..580234be 100644
--- a/book-example/src/cli/build.md
+++ b/book-example/src/cli/build.md
@@ -14,8 +14,8 @@ convenience. Large books will therefore remain structured when rendered.
 
 #### Specify a directory
 
-Like `init`, the `build` command can take a directory as an argument to use
-instead of the current working directory.
+The `build` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
 
 ```bash
 mdbook build path/to/book
@@ -23,13 +23,16 @@ mdbook build path/to/book
 
 #### --open
 
-When you use the `--open` (`-o`) option, mdbook will open the rendered book in
+When you use the `--open` (`-o`) flag, mdbook will open the rendered book in
 your default web browser after building it.
 
 #### --dest-dir
 
-The `--dest-dir` (`-d`) option allows you to change the output directory for your book.
+The `--dest-dir` (`-d`) option allows you to change the output directory for
+the book. If not specified it will default to the value of the
+`build.build-dir` key in `book.toml`, or to `./book` relative to the book's
+root directory.
 
 -------------------
 
-***note:*** *make sure to run the build command in the root directory and not in the source directory*
+***Note:*** *Make sure to run the build command in the root directory and not in the source directory*
diff --git a/book-example/src/cli/clean.md b/book-example/src/cli/clean.md
index 5fc85ed7..c9644a4a 100644
--- a/book-example/src/cli/clean.md
+++ b/book-example/src/cli/clean.md
@@ -7,12 +7,21 @@ artifacts.
 mdbook clean
 ```
 
-It will try to delete the built book. If a path is provided, it will be used.
-
 #### Specify a directory
 
-Like `init`, the `clean` command can take a directory as an argument to use
-instead of the normal build directory.
+The `clean` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
+
+```bash
+mdbook clean path/to/book
+```
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to override the book's output
+directory, which will be deleted by this command. If not specified it
+will default to the value of the `build.build-dir` key in `book.toml`, or to
+`./book` relative to the book's root directory.
 
 ```bash
 mdbook clean --dest-dir=path/to/book
diff --git a/book-example/src/cli/init.md b/book-example/src/cli/init.md
index 8a899afb..b032350e 100644
--- a/book-example/src/cli/init.md
+++ b/book-example/src/cli/init.md
@@ -1,5 +1,7 @@
 # The init command
-There is some minimal boilerplate that is the same for every new book. It's for this purpose that mdBook includes an `init` command.
+
+There is some minimal boilerplate that is the same for every new book. It's for this purpose
+that mdBook includes an `init` command.
 
 The `init` command is used like this:
 
@@ -22,23 +24,27 @@ configuration files, etc.
 - The `book` directory is where your book is rendered. All the output is ready to be uploaded
 to a server to be seen by your audience.
 
-- The `SUMMARY.md` file is the most important file, it's the skeleton of your book and is discussed in more detail in another  [chapter](../format/summary.md)
+- The `SUMMARY.md` file is the most important file, it's the skeleton of your book and is
+discussed in more detail [in another chapter](../format/summary.md)
+
+#### Tip: Generate chapters from SUMMARY.md
 
-#### Tip & Trick: Hidden Feature
-When a `SUMMARY.md` file already exists, the `init` command will first parse it and generate the missing files according to the paths used in the `SUMMARY.md`. This allows you to think and create the whole structure of your book and then let mdBook generate it for you.
+When a `SUMMARY.md` file already exists, the `init` command will first parse it and generate the
+missing files according to the paths used in the `SUMMARY.md`. This allows you to think and create
+the whole structure of your book and then let mdBook generate it for you.
 
 #### Specify a directory
 
-When using the `init` command, you can also specify a directory, instead of using the current working directory,
-by appending a path to the command:
+The `init` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
 
 ```bash
 mdbook init path/to/book
 ```
 
-## --theme
+#### --theme
 
-When you use the `--theme` argument, the default theme will be copied into a directory
+When you use the `--theme` flag, the default theme will be copied into a directory
 called `theme` in your source directory so that you can modify it.
 
 The theme is selectively overwritten, this means that if you don't want to overwrite a
diff --git a/book-example/src/cli/serve.md b/book-example/src/cli/serve.md
index 43e6e8f1..ef272947 100644
--- a/book-example/src/cli/serve.md
+++ b/book-example/src/cli/serve.md
@@ -1,40 +1,50 @@
 # The serve command
 
-The `serve` command is useful when you want to preview your book. It also does hot reloading of the webpage whenever a file changes.
-It achieves this by serving the books content over `localhost:3000` (unless otherwise configured, see below) and runs a websocket server on `localhost:3001` which triggers the reloads.
-This preferred by many for writing books with mdbook because it allows for you to see the result of your work instantly after every file change.
+The serve command is used to preview a book by serving it over HTTP at
+`localhost:3000` by default. Additionally it watches the book's directory
+for changes, rebuilding the book and refreshing clients for each change.
+A websocket connection is used to trigger the client-side refresh.
 
 #### Specify a directory
 
-Like `watch`, `serve` can take a directory as an argument to use instead of
-the current working directory.
+The `serve` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
 
 ```bash
 mdbook serve path/to/book
 ```
 
-
 #### Server options
 
-`serve` has four options: the http port, the websocket port, the interface to serve on, and the public address of the server so that the browser may reach the websocket server.
+`serve` has four options: the HTTP port, the WebSocket port, the HTTP hostname
+to listen on, and the hostname for the browser to connect to for WebSockets.
 
-For example: suppose you had an nginx server for SSL termination which has a public address of 192.168.1.100 on port 80 and proxied that to 127.0.0.1 on port 8000. To run use the nginx proxy do:
+For example: suppose you have an nginx server for SSL termination which has a
+public address of 192.168.1.100 on port 80 and proxied that to 127.0.0.1 on
+port 8000. To run use the nginx proxy do:
 
 ```bash
-mdbook serve path/to/book -p 8000 -i 127.0.0.1 -a 192.168.1.100
+mdbook serve path/to/book -p 8000 -n 127.0.0.1 --websocket-hostname 192.168.1.100
 ```
 
-If you were to want live reloading for this you would need to proxy the websocket calls through nginx as well from `192.168.1.100:<WS_PORT>` to `127.0.0.1:<WS_PORT>`. The `-w` flag allows for the websocket port to be configured.
+If you were to want live reloading for this you would need to proxy the
+websocket calls through nginx as well from `192.168.1.100:<WS_PORT>` to
+`127.0.0.1:<WS_PORT>`. The `-w` flag allows for the websocket port to be
+configured.
 
 #### --open
 
-When you use the `--open` (`-o`) option, mdbook will open the book in your
+When you use the `--open` (`-o`) flag, mdbook will open the book in your
 your default web browser after starting the server.
 
 #### --dest-dir
 
-The `--dest-dir` (`-d`) option allows you to change the output directory for your book.
+The `--dest-dir` (`-d`) option allows you to change the output directory for
+the book. If not specified it will default to the value of the
+`build.build-dir` key in `book.toml`, or to `./book` relative to the book's
+root directory.
 
 -----
 
-***note:*** *the `serve` command has not gotten a lot of testing yet, there could be some rough edges. If you discover a problem, please report it [on Github](https://github.com/rust-lang-nursery/mdBook/issues)*
+***Note:*** *The `serve` command is for testing, and is not intended
+to be a complete HTTP server for a website.*
diff --git a/book-example/src/cli/test.md b/book-example/src/cli/test.md
index feeb4e9d..3d1b6591 100644
--- a/book-example/src/cli/test.md
+++ b/book-example/src/cli/test.md
@@ -1,19 +1,53 @@
 # The test command
 
-When writing a book, you sometimes need to automate some tests. For example, [The Rust Programming Book](https://doc.rust-lang.org/stable/book/) uses a lot of code examples that could get outdated.
-Therefore it is very important for them to be able to automatically test these code examples.
+When writing a book, you sometimes need to automate some tests. For example,
+[The Rust Programming Book](https://doc.rust-lang.org/stable/book/) uses a lot
+of code examples that could get outdated. Therefore it is very important for
+them to be able to automatically test these code examples.
 
-mdBook supports a `test` command that will run all available tests in mdBook. At the moment, only one test is available:
-*"Test Rust code examples using Rustdoc"*, but I hope this will be expanded in the future to include more tests like:
+mdBook supports a `test` command that will run all available tests in a book.
+At the moment, only rustdoc tests are supported, but this may be expanded upon
+in the future.
 
-- checking for broken links
-- checking for unused files
-- ...
+#### Disable tests on a code block
 
-In the future I would like the user to be able to enable / disable test from the `book.toml` configuration file and support custom tests.
+rustdoc doesn't test code blocks which contain the `ignore` attribute:
+
+    ```rust,ignore
+    fn main() {}
+    ```
+
+rustdoc also doesn't test code blocks which specify a language other than Rust:
+
+    ```markdown
+    **Foo**: _bar_
+    ```
+
+rustdoc *does* test code blocks which have no language specified:
+
+    ```
+    This is going to cause an error!
+    ```
+
+#### Specify a directory
+
+The `test` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
 
-**How to use it:**
 ```bash
-$ mdbook test
-[*]: Testing file: "/mdBook/book-example/src/README.md”
+mdbook test path/to/book
 ```
+
+#### --library-path
+
+The `--library-path` (`-L`) option allows you to add directories to the library
+search path used by `rustdoc` when it builds and tests the examples. Multiple
+directories can be specified with multiple options (`-L foo -L bar`) or with a
+comma-delimited list (`-L foo,bar`).
+
+#### --dest-dir
+
+The `--dest-dir` (`-d`) option allows you to change the output directory for
+the book. If not specified it will default to the value of the
+`build.build-dir` key in `book.toml`, or to `./book` relative to the book's
+root directory.
diff --git a/book-example/src/cli/watch.md b/book-example/src/cli/watch.md
index a0cda04e..7e65ba5f 100644
--- a/book-example/src/cli/watch.md
+++ b/book-example/src/cli/watch.md
@@ -1,12 +1,14 @@
 # The watch command
 
-The `watch` command is useful when you want your book to be rendered on every file change.
-You could repeatedly issue `mdbook build` every time a file is changed. But using `mdbook watch` once will watch your files and will trigger a build automatically whenever you modify a file.
+The `watch` command is useful when you want your book to be rendered on every
+file change. You could repeatedly issue `mdbook build` every time a file is
+changed. But using `mdbook watch` once will watch your files and will trigger
+a build automatically whenever you modify a file.
 
 #### Specify a directory
 
-Like `init` and `build`, `watch` can take a directory as an argument to use
-instead of the current working directory.
+The `watch` command can take a directory as an argument to use as the book's
+root instead of the current working directory.
 
 ```bash
 mdbook watch path/to/book
@@ -19,8 +21,7 @@ your default web browser.
 
 #### --dest-dir
 
-The `--dest-dir` (`-d`) option allows you to change the output directory for your book.
-
------
-
-***note:*** *the `watch` command has not gotten a lot of testing yet, there could be some rough edges. If you discover a problem, please report it [on Github](https://github.com/rust-lang-nursery/mdBook/issues)*
+The `--dest-dir` (`-d`) option allows you to change the output directory for
+the book. If not specified it will default to the value of the
+`build.build-dir` key in `book.toml`, or to `./book` relative to the book's
+root directory.
diff --git a/book-example/src/format/mdbook.md b/book-example/src/format/mdbook.md
index 5f2e4ff1..44685a4e 100644
--- a/book-example/src/format/mdbook.md
+++ b/book-example/src/format/mdbook.md
@@ -29,7 +29,7 @@ Will render as
 With the following syntax, you can include files into your book:
 
 ```hbs
-\{{#include file.rs}}
+{{#include file.rs}}
 ```
 
 The path to the file has to be relative from the current source file.
@@ -37,10 +37,10 @@ The path to the file has to be relative from the current source file.
 Usually, this command is used for including code snippets and examples. In this case, oftens one would include a specific part of the file e.g. which only contains the relevant lines for the example. We support four different modes of partial includes:
 
 ```hbs
-\{{#include file.rs:2}}
-\{{#include file.rs::10}}
-\{{#include file.rs:2:}}
-\{{#include file.rs:2:10}}
+{{#include file.rs:2}}
+{{#include file.rs::10}}
+{{#include file.rs:2:}}
+{{#include file.rs:2:10}}
 ```
 
 The first command only includes the second line from file `file.rs`. The second command includes all lines up to line 10, i.e. the lines from 11 till the end of the file are omitted. The third command includes all lines from line 2, i.e. the first line is omitted. The last command includes the excerpt of `file.rs` consisting of lines 2 to 10.
@@ -50,7 +50,7 @@ The first command only includes the second line from file `file.rs`. The second
 With the following syntax, you can insert runnable Rust files into your book:
 
 ```hbs
-\{{#playpen file.rs}}
+{{#playpen file.rs}}
 ```
 
 The path to the Rust file has to be relative from the current source file.
diff --git a/book-example/src/format/theme/index-hbs.md b/book-example/src/format/theme/index-hbs.md
index 33b05dc9..22ee0451 100644
--- a/book-example/src/format/theme/index-hbs.md
+++ b/book-example/src/format/theme/index-hbs.md
@@ -37,7 +37,7 @@ Since the original directory structure is maintained, it is useful to prepend re
 
 In addition to the properties you can access, there are some handlebars helpers at your disposal.
 
-1.  ### toc
+### 1. toc
 
     The toc helper is used like this
 
@@ -68,7 +68,7 @@ In addition to the properties you can access, there are some handlebars helpers
     </script>
     ```
 
-2.  ### previous / next
+### 2. previous / next
 
     The previous and next helpers expose a `link` and `name` property to the previous and next chapters.
 
@@ -87,5 +87,4 @@ In addition to the properties you can access, there are some handlebars helpers
 
 ------
 
-*If you would like me to expose other properties or helpers, please [create a new issue](https://github.com/rust-lang-nursery/mdBook/issues)
-and I will consider it.*
+*If you would like other properties or helpers exposed, please [create a new issue](https://github.com/rust-lang-nursery/mdBook/issues)*
diff --git a/src/cmd/build.rs b/src/cmd/build.rs
index 7887c06c..350a3ece 100644
--- a/src/cmd/build.rs
+++ b/src/cmd/build.rs
@@ -1,21 +1,21 @@
 use clap::{App, ArgMatches, SubCommand};
 use mdbook::errors::Result;
 use mdbook::MDBook;
-use std::path::PathBuf;
 use {get_book_dir, open};
 
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("build")
-        .about("Build the book from the markdown files")
-        .arg_from_usage("-o, --open 'Open the compiled book in a web browser'")
+        .about("Builds a book from its markdown files")
         .arg_from_usage(
-            "-d, --dest-dir=[dest-dir] 'The output directory for your book{n}(Defaults to ./book \
-             when omitted)'",
+            "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
+             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
         )
         .arg_from_usage(
-            "[dir] 'A directory for your book{n}(Defaults to Current Directory when omitted)'",
+            "[dir] 'Root directory for the book{n}\
+             (Defaults to the Current Directory when omitted)'",
         )
+        .arg_from_usage("-o, --open 'Opens the compiled book in a web browser'")
 }
 
 // Build command implementation
@@ -24,7 +24,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     let mut book = MDBook::load(&book_dir)?;
 
     if let Some(dest_dir) = args.value_of("dest-dir") {
-        book.config.build.build_dir = PathBuf::from(dest_dir);
+        book.config.build.build_dir = dest_dir.into();
     }
 
     book.build()?;
diff --git a/src/cmd/clean.rs b/src/cmd/clean.rs
index 92b69566..9bcf3f20 100644
--- a/src/cmd/clean.rs
+++ b/src/cmd/clean.rs
@@ -3,15 +3,18 @@ use get_book_dir;
 use mdbook::errors::*;
 use mdbook::MDBook;
 use std::fs;
-use std::path::PathBuf;
 
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("clean")
-        .about("Delete built book")
+        .about("Deletes a built book")
         .arg_from_usage(
-            "-d, --dest-dir=[dest-dir] 'The directory of built book{n}(Defaults to ./book when \
-             omitted)'",
+            "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
+             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
+        )
+        .arg_from_usage(
+            "[dir] 'Root directory for the book{n}\
+             (Defaults to the Current Directory when omitted)'",
         )
 }
 
@@ -21,7 +24,7 @@ pub fn execute(args: &ArgMatches) -> ::mdbook::errors::Result<()> {
     let book = MDBook::load(&book_dir)?;
 
     let dir_to_remove = match args.value_of("dest-dir") {
-        Some(dest_dir) => PathBuf::from(dest_dir),
+        Some(dest_dir) => dest_dir.into(),
         None => book.root.join(&book.config.build.build_dir),
     };
     fs::remove_dir_all(&dir_to_remove).chain_err(|| "Unable to remove the build directory")?;
diff --git a/src/cmd/init.rs b/src/cmd/init.rs
index 134eda80..629563b2 100644
--- a/src/cmd/init.rs
+++ b/src/cmd/init.rs
@@ -10,12 +10,12 @@ use std::process::Command;
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("init")
-        .about("Create boilerplate structure and files in the directory")
+        .about("Creates the boilerplate structure and files for a new book")
         // the {n} denotes a newline which will properly aligned in all help messages
-        .arg_from_usage("[dir] 'A directory for your book{n}(Defaults to Current Directory \
-                         when omitted)'")
+        .arg_from_usage("[dir] 'Directory to create the book in{n}\
+            (Defaults to the Current Directory when omitted)'")
         .arg_from_usage("--theme 'Copies the default theme into your source folder'")
-        .arg_from_usage("--force 'skip confirmation prompts'")
+        .arg_from_usage("--force 'Skips confirmation prompts'")
 }
 
 // Init command implementation
diff --git a/src/cmd/serve.rs b/src/cmd/serve.rs
index 22aa3ab9..421c37e1 100644
--- a/src/cmd/serve.rs
+++ b/src/cmd/serve.rs
@@ -7,7 +7,7 @@ use self::iron::{
 };
 #[cfg(feature = "watch")]
 use super::watch;
-use clap::{App, ArgMatches, SubCommand};
+use clap::{App, Arg, ArgMatches, SubCommand};
 use mdbook::errors::*;
 use mdbook::utils;
 use mdbook::MDBook;
@@ -19,23 +19,52 @@ struct ErrorRecover;
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("serve")
-        .about("Serve the book at http://localhost:3000. Rebuild and reload on change.")
+        .about("Serves a book at http://localhost:3000, and rebuilds it on changes")
         .arg_from_usage(
-            "[dir] 'A directory for your book{n}(Defaults to Current Directory when omitted)'",
+            "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
+             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
         )
-        .arg_from_usage("-p, --port=[port] 'Use another port{n}(Defaults to 3000)'")
         .arg_from_usage(
-            "-w, --websocket-port=[ws-port] 'Use another port for the websocket connection \
-             (livereload){n}(Defaults to 3001)'",
+            "[dir] 'Root directory for the book{n}\
+             (Defaults to the Current Directory when omitted)'",
         )
-        .arg_from_usage(
-            "-i, --interface=[interface] 'Interface to listen on{n}(Defaults to localhost)'",
+        .arg(
+            Arg::with_name("hostname")
+                .short("n")
+                .long("hostname")
+                .takes_value(true)
+                .default_value("localhost")
+                .empty_values(false)
+                .help("Hostname to listen on for HTTP connections"),
         )
-        .arg_from_usage(
-            "-a, --address=[address] 'Address that the browser can reach the websocket server \
-             from{n}(Defaults to the interface address)'",
+        .arg(
+            Arg::with_name("port")
+                .short("p")
+                .long("port")
+                .takes_value(true)
+                .default_value("3000")
+                .empty_values(false)
+                .help("Port to use for HTTP connections"),
+        )
+        .arg(
+            Arg::with_name("websocket-hostname")
+                .long("websocket-hostname")
+                .takes_value(true)
+                .empty_values(false)
+                .help(
+                    "Hostname to connect to for WebSockets connections (Defaults to the HTTP hostname)",
+                ),
+        )
+        .arg(
+            Arg::with_name("websocket-port")
+                .short("w")
+                .long("websocket-port")
+                .takes_value(true)
+                .default_value("3001")
+                .empty_values(false)
+                .help("Port to use for WebSockets livereload connections"),
         )
-        .arg_from_usage("-o, --open 'Open the book server in a web browser'")
+        .arg_from_usage("-o, --open 'Opens the book server in a web browser'")
 }
 
 // Watch command implementation
@@ -43,19 +72,23 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
     let mut book = MDBook::load(&book_dir)?;
 
-    let port = args.value_of("port").unwrap_or("3000");
-    let ws_port = args.value_of("websocket-port").unwrap_or("3001");
-    let interface = args.value_of("interface").unwrap_or("localhost");
-    let public_address = args.value_of("address").unwrap_or(interface);
+    let port = args.value_of("port").unwrap();
+    let ws_port = args.value_of("websocket-port").unwrap();
+    let hostname = args.value_of("hostname").unwrap();
+    let public_address = args.value_of("websocket-address").unwrap_or(hostname);
     let open_browser = args.is_present("open");
 
-    let address = format!("{}:{}", interface, port);
-    let ws_address = format!("{}:{}", interface, ws_port);
+    let address = format!("{}:{}", hostname, port);
+    let ws_address = format!("{}:{}", hostname, ws_port);
 
     let livereload_url = format!("ws://{}:{}", public_address, ws_port);
     book.config
         .set("output.html.livereload-url", &livereload_url)?;
 
+    if let Some(dest_dir) = args.value_of("dest-dir") {
+        book.config.build.build_dir = dest_dir.into();
+    }
+
     book.build()?;
 
     let mut chain = Chain::new(staticfile::Static::new(book.build_dir_for("html")));
@@ -87,10 +120,8 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
 
         // FIXME: This area is really ugly because we need to re-set livereload :(
 
-        let livereload_url = livereload_url.clone();
-
         let result = MDBook::load(&book_dir)
-            .and_then(move |mut b| {
+            .and_then(|mut b| {
                 b.config.set("output.html.livereload-url", &livereload_url)?;
                 Ok(b)
             })
diff --git a/src/cmd/test.rs b/src/cmd/test.rs
index 8409590a..dac841c6 100644
--- a/src/cmd/test.rs
+++ b/src/cmd/test.rs
@@ -1,4 +1,4 @@
-use clap::{App, ArgMatches, SubCommand};
+use clap::{App, Arg, ArgMatches, SubCommand};
 use get_book_dir;
 use mdbook::errors::Result;
 use mdbook::MDBook;
@@ -6,11 +6,24 @@ use mdbook::MDBook;
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("test")
-        .about("Test that code samples compile")
-        .arg_from_usage("-L, --library-path [DIR]... 'directories to add to crate search path'")
+        .about("Tests that a book's Rust code samples compile")
         .arg_from_usage(
-            "[dir] 'A directory for your book{n}(Defaults to Current Directory when omitted)'",
+            "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
+             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
         )
+        .arg_from_usage(
+            "[dir] 'Root directory for the book{n}\
+             (Defaults to the Current Directory when omitted)'",
+        )
+        .arg(Arg::with_name("library-path")
+            .short("L")
+            .long("library-path")
+            .value_name("dir")
+            .takes_value(true)
+            .require_delimiter(true)
+            .multiple(true)
+            .empty_values(false)
+            .help("A comma-separated list of directories to add to {n}the crate search path when building tests"))
 }
 
 // test command implementation
@@ -21,6 +34,10 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     let book_dir = get_book_dir(args);
     let mut book = MDBook::load(&book_dir)?;
 
+    if let Some(dest_dir) = args.value_of("dest-dir") {
+        book.config.build.build_dir = dest_dir.into();
+    }
+
     book.test(library_paths)?;
 
     Ok(())
diff --git a/src/cmd/watch.rs b/src/cmd/watch.rs
index e5848970..0f809251 100644
--- a/src/cmd/watch.rs
+++ b/src/cmd/watch.rs
@@ -13,11 +13,16 @@ use {get_book_dir, open};
 // Create clap subcommand arguments
 pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
     SubCommand::with_name("watch")
-        .about("Watch the files for changes")
-        .arg_from_usage("-o, --open 'Open the compiled book in a web browser'")
+        .about("Watches a book's files and rebuilds it on changes")
+        .arg_from_usage(
+            "-d, --dest-dir=[dest-dir] 'Output directory for the book{n}\
+             (If omitted, uses build.build-dir from book.toml or defaults to ./book)'",
+        )
         .arg_from_usage(
-            "[dir] 'A directory for your book{n}(Defaults to Current Directory when omitted)'",
+            "[dir] 'Root directory for the book{n}\
+             (Defaults to the Current Directory when omitted)'",
         )
+        .arg_from_usage("-o, --open 'Open the compiled book in a web browser'")
 }
 
 // Watch command implementation
diff --git a/src/main.rs b/src/main.rs
index 8a1a2e9b..86147532 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -20,26 +20,27 @@ use std::path::{Path, PathBuf};
 
 mod cmd;
 
-const NAME: &'static str = "mdbook";
+const NAME: &'static str = "mdBook";
+const VERSION: &'static str = concat!("v", crate_version!());
 
 fn main() {
     init_logger();
 
     // Create a list of valid arguments and sub-commands
     let app = App::new(NAME)
-                .about("Create a book in form of a static website from markdown files")
-                .author("Mathieu David <mathieudavid@mathieudavid.org>")
-                // Get the version from our Cargo.toml using clap's crate_version!() macro
-                .version(concat!("v",crate_version!()))
-                .setting(AppSettings::ArgRequiredElseHelp)
-                .after_help("For more information about a specific command, \
-                             try `mdbook <command> --help`\n\
-                             Source code for mdbook available \
-                             at: https://github.com/rust-lang-nursery/mdBook")
-                .subcommand(cmd::init::make_subcommand())
-                .subcommand(cmd::build::make_subcommand())
-                .subcommand(cmd::test::make_subcommand())
-                .subcommand(cmd::clean::make_subcommand());
+        .about("Creates a book from markdown files")
+        .author("Mathieu David <mathieudavid@mathieudavid.org>")
+        .version(VERSION)
+        .setting(AppSettings::GlobalVersion)
+        .setting(AppSettings::ArgRequiredElseHelp)
+        .after_help(
+            "For more information about a specific command, try `mdbook <command> --help`\n\
+             The source code for mdBook is available at: https://github.com/rust-lang-nursery/mdBook",
+        )
+        .subcommand(cmd::init::make_subcommand())
+        .subcommand(cmd::build::make_subcommand())
+        .subcommand(cmd::test::make_subcommand())
+        .subcommand(cmd::clean::make_subcommand());
 
     #[cfg(feature = "watch")]
     let app = app.subcommand(cmd::watch::make_subcommand());