fix: Dont mention unused subcommands

src/app/parser.rs

@@ -928,7 +928,7 @@ where
                     }
 
                     if arg_os.starts_with(b"--") {
-                        needs_val_of = self.parse_long_arg(matcher, &arg_os)?;
+                        needs_val_of = self.parse_long_arg(matcher, &arg_os, it)?;
                         debugln!(
                             "Parser:get_matches_with: After parse_long_arg {:?}",
                             needs_val_of
@@ -1554,11 +1554,16 @@ where
         }
     }
 
-    fn parse_long_arg(
+    fn parse_long_arg<I, T>(
         &mut self,
         matcher: &mut ArgMatcher<'a>,
         full_arg: &OsStr,
-    ) -> ClapResult<ParseResult<'a>> {
+        it: &mut Peekable<I>,
+    ) -> ClapResult<ParseResult<'a>>
+    where
+        I: Iterator<Item = T>,
+        T: Into<OsString> + Clone,
+    {
         // maybe here lifetime should be 'a
         debugln!("Parser::parse_long_arg;");
 
@@ -1614,8 +1619,14 @@ where
         }
 
         debugln!("Parser::parse_long_arg: Didn't match anything");
-        self.did_you_mean_error(arg.to_str().expect(INVALID_UTF8), matcher)
-            .map(|_| ParseResult::NotFound)
+
+        let args_rest: Vec<_> = it.map(|x| x.clone().into()).collect();
+        let args_rest2: Vec<_> = args_rest.iter().map(|x| x.to_str().expect(INVALID_UTF8)).collect();
+        self.did_you_mean_error(
+            arg.to_str().expect(INVALID_UTF8),
+            matcher,
+            &args_rest2[..]
+        ).map(|_| ParseResult::NotFound)
     }
 
     #[cfg_attr(feature = "lints", allow(len_zero))]
@@ -1872,9 +1883,9 @@ where
         Ok(ParseResult::Flag)
     }
 
-    fn did_you_mean_error(&self, arg: &str, matcher: &mut ArgMatcher<'a>) -> ClapResult<()> {
+    fn did_you_mean_error(&self, arg: &str, matcher: &mut ArgMatcher<'a>, args_rest: &[&str]) -> ClapResult<()> {
         // Didn't match a flag or option
-        let suffix = suggestions::did_you_mean_flag_suffix(arg, longs!(self), &self.subcommands);
+        let suffix = suggestions::did_you_mean_flag_suffix(arg, &args_rest, longs!(self), &self.subcommands);
 
         // Add the arg to the matches to build a proper usage string
         if let Some(name) = suffix.1 {

src/suggestions.rs

@@ -44,6 +44,7 @@ where
 #[cfg_attr(feature = "lints", allow(needless_lifetimes))]
 pub fn did_you_mean_flag_suffix<'z, T, I>(
     arg: &str,
+    args_rest: &'z [&str],
     longs: I,
     subcommands: &'z [App],
 ) -> (String, Option<&'z str>)
@@ -51,16 +52,18 @@ where
     T: AsRef<str> + 'z,
     I: IntoIterator<Item = &'z T>,
 {
-    match did_you_mean(arg, longs) {
-        Some(candidate) => {
-            let suffix = format!(
-                "\n\tDid you mean {}{}?",
-                Format::Good("--"),
-                Format::Good(candidate)
+    if let Some(candidate) = did_you_mean(arg, longs) {
+        let suffix = format!(
+            "\n\tDid you mean {}{}?",
+            Format::Good("--"),
+            Format::Good(candidate)
             );
-            return (suffix, Some(candidate));
-        }
-        None => for subcommand in subcommands {
+        return (suffix, Some(candidate));
+    }
+
+    subcommands
+        .into_iter()
+        .filter_map(|subcommand| {
             let opts = subcommand
                 .p
                 .flags
@@ -68,18 +71,21 @@ where
                 .filter_map(|f| f.s.long)
                 .chain(subcommand.p.opts.iter().filter_map(|o| o.s.long));
 
-            if let Some(candidate) = did_you_mean(arg, opts) {
-                let suffix = format!(
-                    "\n\tDid you mean to put '{}{}' after the subcommand '{}'?",
-                    Format::Good("--"),
-                    Format::Good(candidate),
-                    Format::Good(subcommand.get_name())
-                );
-                return (suffix, Some(candidate));
-            }
-        },
-    }
-    (String::new(), None)
+            let candidate = did_you_mean(arg, opts)?;
+            let score = args_rest.iter().position(|x| *x == subcommand.get_name())?;
+
+            let suffix = format!(
+                "\n\tDid you mean to put '{}{}' after the subcommand '{}'?",
+                Format::Good("--"),
+                Format::Good(candidate),
+                Format::Good(subcommand.get_name())
+            );
+
+            Some((score, (suffix, Some(candidate))))
+        })
+        .min_by_key(|&(score, _)| score)
+        .map(|(_, suggestion)| suggestion)
+        .unwrap_or_else(|| (String::new(), None))
 }
 
 /// Returns a suffix that can be empty, or is the standard 'did you mean' phrase

tests/subcommands.rs

@@ -42,15 +42,6 @@ USAGE:
 
 For more information try --help";
 
-#[cfg(feature = "suggestions")]
-static DYM_ARG: &'static str = "error: Found argument '--subcm' which wasn't expected, or isn't valid in this context
-\tDid you mean to put '--subcmdarg' after the subcommand 'subcmd'?
-
-USAGE:
-    dym [SUBCOMMAND]
-
-For more information try --help";
-
 #[test]
 fn subcommand() {
     let m = App::new("test")
@@ -137,10 +128,34 @@ fn subcmd_did_you_mean_output() {
 #[test]
 #[cfg(feature="suggestions")]
 fn subcmd_did_you_mean_output_arg() {
+    static EXPECTED: &'static str = "error: Found argument '--subcmarg' which wasn't expected, or isn't valid in this context
+\tDid you mean to put '--subcmdarg' after the subcommand 'subcmd'?
+
+USAGE:
+    dym [SUBCOMMAND]
+
+For more information try --help";
+
     let app = App::new("dym")
         .subcommand(SubCommand::with_name("subcmd")
             .arg_from_usage("-s --subcmdarg [subcmdarg] 'tests'") );
-    assert!(test::compare_output(app, "dym --subcm foo", DYM_ARG, true));
+    assert!(test::compare_output(app, "dym --subcmarg subcmd", EXPECTED, true));
+}
+
+#[test]
+#[cfg(feature="suggestions")]
+fn subcmd_did_you_mean_output_arg_false_positives() {
+    static EXPECTED: &'static str = "error: Found argument '--subcmarg' which wasn't expected, or isn't valid in this context
+
+USAGE:
+    dym [SUBCOMMAND]
+
+For more information try --help";
+
+    let app = App::new("dym")
+        .subcommand(SubCommand::with_name("subcmd")
+            .arg_from_usage("-s --subcmdarg [subcmdarg] 'tests'") );
+    assert!(test::compare_output(app, "dym --subcmarg foo", EXPECTED, true));
 }
 
 #[test]
@@ -198,4 +213,4 @@ fn issue_1031_args_with_same_name_no_more_vals() {
     let m = res.unwrap();
     assert_eq!(m.value_of("ui-path"), Some("value"));
     assert_eq!(m.subcommand_name(), Some("signer"));
-}
+}