Ambiguous suggetions for InferSubcommands

Closes #1655

src/parse/errors.rs

@@ -628,7 +628,7 @@ impl Error {
             cause: format!("The subcommand '{}' wasn't recognized", s),
             message: format!(
                 "{} The subcommand '{}' wasn't recognized\n\t\
-                 Did you mean '{}'?\n\n\
+                 Did you mean {}?\n\n\
                  If you believe you received this message in error, try \
                  re-running with '{} {} {}'\n\n\
                  {}\n\n\

src/parse/features/suggestions.rs

@@ -1,3 +1,5 @@
+use std::cmp::Ordering;
+
 // Third Party
 #[cfg(feature = "suggestions")]
 use strsim;
@@ -6,35 +8,32 @@ use strsim;
 use crate::build::App;
 use crate::output::fmt::Format;
 
-/// Produces a string from a given list of possible values which is similar to
-/// the passed in value `v` with a certain confidence.
+/// Produces multiple strings from a given list of possible values which are similar
+/// to the passed in value `v` within a certain confidence by least confidence.
 /// Thus in a list of possible values like ["foo", "bar"], the value "fop" will yield
 /// `Some("foo")`, whereas "blark" would yield `None`.
 #[cfg(feature = "suggestions")]
-pub fn did_you_mean<T, I>(v: &str, possible_values: I) -> Option<String>
+pub fn did_you_mean<T, I>(v: &str, possible_values: I) -> Vec<String>
 where
     T: AsRef<str>,
     I: IntoIterator<Item = T>,
 {
-    let mut candidate: Option<(f64, String)> = None;
-    for pv in possible_values {
-        let confidence = strsim::jaro_winkler(v, pv.as_ref());
-        if confidence > 0.8 && (candidate.is_none() || (candidate.as_ref().unwrap().0 < confidence))
-        {
-            candidate = Some((confidence, pv.as_ref().to_owned()));
-        }
-    }
-
-    candidate.map(|(_, candidate)| candidate)
+    let mut candidates: Vec<(f64, String)> = possible_values
+        .into_iter()
+        .map(|pv| (strsim::jaro_winkler(v, pv.as_ref()), pv.as_ref().to_owned()))
+        .filter(|(confidence, _pv)| *confidence > 0.8)
+        .collect();
+    candidates.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap_or(Ordering::Equal));
+    candidates.into_iter().map(|(_confidence, pv)| pv).collect()
 }
 
 #[cfg(not(feature = "suggestions"))]
-pub fn did_you_mean<T, I>(_: &str, _: I) -> Option<String>
+pub fn did_you_mean<T, I>(_: &str, _: I) -> Vec<String>
 where
     T: AsRef<str>,
     I: IntoIterator<Item = T>,
 {
-    None
+    Vec::new()
 }
 
 /// Returns a suffix that can be empty, or is the standard 'did you mean' phrase
@@ -47,7 +46,7 @@ where
     T: AsRef<str>,
     I: IntoIterator<Item = T>,
 {
-    match did_you_mean(arg, longs) {
+    match did_you_mean(arg, longs).pop() {
         Some(ref candidate) => {
             let suffix = format!(
                 "\n\tDid you mean {}{}?",
@@ -62,7 +61,9 @@ where
                 if let Some(ref candidate) = did_you_mean(
                     arg,
                     longs!(subcommand).map(|x| x.to_string_lossy().into_owned()),
-                ) {
+                )
+                .pop()
+                {
                     let suffix = format!(
                         "\n\tDid you mean to put '{}{}' after the subcommand '{}'?",
                         Format::Good("--"),
@@ -83,7 +84,7 @@ where
     T: AsRef<str>,
     I: IntoIterator<Item = T>,
 {
-    match did_you_mean(arg, values) {
+    match did_you_mean(arg, values).pop() {
         Some(ref candidate) => {
             let suffix = format!("\n\tDid you mean '{}'?", Format::Good(candidate));
             (suffix, Some(candidate.to_owned()))
@@ -102,6 +103,12 @@ mod test {
         assert_eq!(did_you_mean("tst", p_vals.iter()), Some("test"));
     }
 
+    #[test]
+    fn possible_values_match() {
+        let p_vals = ["test", "temp"];
+        assert_eq!(did_you_mean("te", p_vals.iter()), Some("test"));
+    }
+
     #[test]
     fn possible_values_nomatch() {
         let p_vals = ["test", "possible", "values"];

src/parse/parser.rs

@@ -547,12 +547,13 @@ where
                 || self.is_set(AS::AllowExternalSubcommands)
                 || self.is_set(AS::InferSubcommands))
             {
-                if let Some(cdate) =
-                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self.app))
-                {
+                let cands =
+                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self.app));
+                if !cands.is_empty() {
+                    let cands: Vec<_> = cands.iter().map(|cand| format!("'{}'", cand)).collect();
                     return Err(ClapError::invalid_subcommand(
                         arg_os.to_string_lossy().into_owned(),
-                        cdate,
+                        cands.join(" or "),
                         self.app.bin_name.as_ref().unwrap_or(&self.app.name),
                         &*Usage::new(self).create_usage_with_title(&[]),
                         self.app.color(),
@@ -608,8 +609,8 @@ where
 
                     if self.is_new_arg(n, needs_val_of)
                         || sc_match
-                        || suggestions::did_you_mean(&n.to_string_lossy(), sc_names!(self.app))
-                            .is_some()
+                        || !suggestions::did_you_mean(&n.to_string_lossy(), sc_names!(self.app))
+                            .is_empty()
                     {
                         debugln!("Parser::get_matches_with: Bumping the positional counter...");
                         pos_counter += 1;
@@ -728,12 +729,13 @@ where
                     self.app.color(),
                 ));
             } else if !has_args || self.is_set(AS::InferSubcommands) && self.has_subcommands() {
-                if let Some(cdate) =
-                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self.app))
-                {
+                let cands =
+                    suggestions::did_you_mean(&*arg_os.to_string_lossy(), sc_names!(self.app));
+                if !cands.is_empty() {
+                    let cands: Vec<_> = cands.iter().map(|cand| format!("'{}'", cand)).collect();
                     return Err(ClapError::invalid_subcommand(
                         arg_os.to_string_lossy().into_owned(),
-                        cdate,
+                        cands.join(" or "),
                         self.app.bin_name.as_ref().unwrap_or(&self.app.name),
                         &*Usage::new(self).create_usage_with_title(&[]),
                         self.app.color(),

tests/subcommands.rs

@@ -39,6 +39,17 @@ USAGE:
 
 For more information try --help";
 
+#[cfg(feature = "suggestions")]
+static DYM_SUBCMD_AMBIGUOUS: &str = "error: The subcommand 'te' wasn't recognized
+	Did you mean 'test' or 'temp'?
+
+If you believe you received this message in error, try re-running with 'dym -- te'
+
+USAGE:
+    dym [SUBCOMMAND]
+
+For more information try --help";
+
 #[cfg(feature = "suggestions")]
 static DYM_ARG: &str =
     "error: Found argument '--subcm' which wasn't expected, or isn't valid in this context
@@ -136,6 +147,20 @@ fn subcmd_did_you_mean_output() {
     assert!(utils::compare_output(app, "dym subcm", DYM_SUBCMD, true));
 }
 
+#[test]
+#[cfg(feature = "suggestions")]
+fn subcmd_did_you_mean_output_ambiguous() {
+    let app = App::new("dym")
+        .subcommand(App::new("test"))
+        .subcommand(App::new("temp"));
+    assert!(utils::compare_output(
+        app,
+        "dym te",
+        DYM_SUBCMD_AMBIGUOUS,
+        true
+    ));
+}
+
 #[test]
 #[cfg(feature = "suggestions")]
 fn subcmd_did_you_mean_output_arg() {