git-sugdiff: Use `diff_options.parse()` to extract diff options

Config::get():
Change `args` type so we can pass both a `Vec<String>` and
`Vec<&String>`.

diff_options.parse():
* Split diff arguments and program arguments by returning a tuple.
* Exit the args loop once we've parsed an argument.
* Update test
* Add a non-working test for suggestion arguments. An `OPT_OPTIONS`
  argument could be followed by an argument that's not the value of the
  `OPT_OPTIONS` option. Currently, that arg will always be parsed as the
  value. We need to handle this case.

3 files changed, 47 insertions, 6 deletions

diff --git a/src/bin/git-sugdiff.rs b/src/bin/git-sugdiff.rs
index 6b95239..13c3292 100644
--- a/src/bin/git-sugdiff.rs
+++ b/src/bin/git-sugdiff.rs
@@ -22,6 +22,7 @@ use exitcode;
 
 use github_suggestion_cli::{gseprintln, for_suggestion};
 use github_suggestion_cli::config::Config;
+use github_suggestion_cli::diff_options;
 
 
 fn main() {
@@ -30,6 +31,10 @@ fn main() {
     // TODO: Shift all diff options from args, then pass them to Config::get().
     // Add diff options to Command call below.
 
+    let (args, diff_args) = diff_options::parse(&args);
+    dbg!(&args);
+    dbg!(&diff_args);
+
     let config = match Config::get(
         &args,
         "usage: git sugdiff [options] <suggestion>...",
@@ -56,6 +61,7 @@ fn main() {
             match Command::new("git")
                 .arg("--no-pager")
                 .arg("diff")
+                .args(&diff_args)
                 .arg(format!("{}:{}", suggestion.commit(), suggestion.path()))
                 .arg(blob.to_string())
                 .spawn()
diff --git a/src/config.rs b/src/config.rs
index d8732d4..77793c4 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -15,6 +15,7 @@
 
 
 use std::env;
+use std::ffi::OsStr;
 use std::process;
 
 use getopts::{self, Options};
@@ -57,7 +58,9 @@ pub struct Config {
 impl Config {
     /// Set up command line arguments. Extract configuration values from command
     /// line arguments, Git config, and environment variables.
-    pub fn get(args: &[String], usage_brief: &str) -> Result<Self, Error> {
+    // pub fn get<C: IntoIterator>(args: C, usage_brief: &str) -> Result<Self, Error>
+    // where C::Item: AsRef<OsStr>
+    pub fn get<S: AsRef<OsStr>>(args: &[S], usage_brief: &str) -> Result<Self, Error> {
         let mut opts = Options::new();
 
         opts.optopt(
diff --git a/src/diff_options.rs b/src/diff_options.rs
index 587e214..fa0af8e 100644
--- a/src/diff_options.rs
+++ b/src/diff_options.rs
@@ -165,13 +165,15 @@ static OPT_OPTIONS: [&'static str; 19] = [
 
 
 // pub fn parse(args: &[String]) -> &[String] {
-pub fn parse(args: &[String]) -> Vec<&String> {
+pub fn parse(args: &[String]) -> (Vec<&String>, Vec<&String>) {
+    let mut program_args = Vec::new();
     let mut found_args = Vec::new();
     let mut add_next_arg = false;
 
-    for arg in args {
+    'args: for arg in args {
         let find_arg_prefix = arg.find('-');
 
+        // TODO: Ignore suggestion args
         if add_next_arg
             && (
                 find_arg_prefix.is_none()
@@ -188,6 +190,8 @@ pub fn parse(args: &[String]) -> Vec<&String> {
         for flag in FLAGS.iter() {
             if arg.starts_with(flag) {
                 found_args.push(arg);
+
+                continue 'args;
             }
         }
 
@@ -216,6 +220,8 @@ pub fn parse(args: &[String]) -> Vec<&String> {
                 if rest.find('=').is_none() {
                     add_next_arg = true;
                 }
+
+                continue 'args;
             }
         }
 
@@ -230,11 +236,16 @@ pub fn parse(args: &[String]) -> Vec<&String> {
                 if rest.find('=').is_none() {
                     add_next_arg = true;
                 }
+
+                continue 'args;
             }
         }
+
+        // TODO: Otherwise, add to normal arguments list
+        program_args.push(arg)
     }
 
-    found_args
+    (program_args, found_args)
 }
 
 
@@ -261,9 +272,9 @@ mod tests {
             "--relative".to_owned(),
         ];
 
-        let options = parse(&args);
+        let (_, diff_opts) = parse(&args);
 
-        assert_eq!(options, vec![
+        assert_eq!(diff_opts, vec![
             "--diff-filter=A",
             "-D",
             "--color",
@@ -278,6 +289,27 @@ mod tests {
             "--relative",
         ]);
     }
+
+    #[test]
+    fn parse_does_not_consume_suggestion_args() {
+        let args = vec![
+            "--github-token".to_owned(),
+            "MY_TOKEN".to_owned(),
+            "--word-diff".to_owned(),
+            "459692838".to_owned(),
+            "https://github.com/teddywing/git-suggestion/pull/1#discussion_r459691747".to_owned(),
+        ];
+
+        let (options, diff_opts) = parse(&args);
+
+        assert_eq!(diff_opts, vec!["--word-diff"]);
+        assert_eq!(options, vec![
+            "--github-token",
+            "MY_TOKEN",
+            "459692838",
+            "https://github.com/teddywing/git-suggestion/pull/1#discussion_r459691747",
+        ]);
+    }
 }
 
 // -p