Convert CI check process to use a bin instead of testing a lib

This allows us to add some additional commands to the Rust-based part of
this crate.

.travis.yml

@@ -1,4 +1,5 @@
 language: rust
+script: cargo run check # check that the advisory-db is well-formed
 
 branches:
   only:

Cargo.toml

@@ -9,5 +9,10 @@ documentation = "https://github.com/rustsec/advisory-db"
 categories = ["api-bindings", "development-tools"]
 keywords = ["rustsec", "security", "advisory", "vulnerability"]
 
+[[bin]]
+name = "rustsec-advisory-db"
+
 [dependencies]
+gumdrop = "0.4"
+gumdrop_derive = "0.4"
 rustsec = "0.7"

src/lib.rs

@@ -1,20 +0,0 @@
-extern crate rustsec;
-
-#[cfg(test)]
-mod tests {
-    use rustsec::{AdvisoryDatabase, Repository};
-
-    #[test]
-    fn advisories_toml_is_well_formed() {
-        let repo = Repository::open(".").unwrap();
-
-        // Ensure Advisories.toml parses
-        let advisory_count = AdvisoryDatabase::from_repository(&repo)
-            .unwrap()
-            .advisories()
-            .count();
-
-        // Ensure we're parsing some advisories
-        assert!(advisory_count > 5);
-    }
-}

src/main.rs

@@ -0,0 +1,85 @@
+extern crate gumdrop;
+#[macro_use]
+extern crate gumdrop_derive;
+extern crate rustsec;
+
+use gumdrop::Options;
+use rustsec::{AdvisoryDatabase, Repository};
+use std::{env, process::exit};
+
+const MIN_EXPECTED_ADVISORIES: usize = 5;
+
+/// Subcommands
+#[derive(Debug, Options)]
+enum Opts {
+    #[options(help = "show help for a command")]
+    Help(HelpOpts),
+
+    #[options(help = "check the advisory DB is well-formed")]
+    Check(CheckOpts),
+}
+
+/// Options for the `help` command
+#[derive(Debug, Default, Options)]
+struct HelpOpts {
+    #[options(free)]
+    commands: Vec<String>,
+}
+
+/// Options for the `check` command
+#[derive(Debug, Default, Options)]
+struct CheckOpts {}
+
+fn main() {
+    let args: Vec<_> = env::args().collect();
+
+    let opts = Opts::parse_args_default(&args[1..]).unwrap_or_else(|e| {
+        match e.to_string().as_ref() {
+            // Show usage if no command name is given or if "help" is given
+            "missing command name" => help(&[]),
+            string => eprintln!("{}: {}", args[0], string),
+        }
+
+        exit(2);
+    });
+
+    match opts {
+        Opts::Help(opts) => help(&opts.commands),
+        Opts::Check(_) => check(),
+    }
+
+    exit(0);
+}
+
+/// Print help message
+fn help(_commands: &[String]) {
+    println!("Usage: {} [COMMAND] [OPTIONS]", env::args().next().unwrap());
+    println!();
+    println!("Available commands:");
+    println!();
+    println!("{}", Opts::command_list().unwrap());
+    println!();
+}
+
+fn check() {
+    let repo = Repository::open(".").unwrap();
+
+    // Ensure Advisories.toml parses
+    let advisory_count = AdvisoryDatabase::from_repository(&repo)
+        .unwrap()
+        .advisories()
+        .count();
+
+    // Ensure we're parsing some advisories
+    if advisory_count > MIN_EXPECTED_ADVISORIES {
+        println!(
+            "*** Check succeeded! Successfully parsed {} advisories.",
+            advisory_count
+        );
+    } else {
+        panic!(
+            "Missing advisories! Expected at least {}, but got {}",
+            MIN_EXPECTED_ADVISORIES, advisory_count
+        );
+    }
+}