Merge pull request #2771 from mustafa-guler/master

Fix bug with duplicate error messages

src/output/usage.rs

@@ -1,6 +1,8 @@
 // std
 use std::collections::BTreeMap;
 
+use indexmap::IndexSet;
+
 // Internal
 use crate::{
     build::AppSettings as AS,
@@ -382,17 +384,19 @@ impl<'help, 'app, 'parser> Usage<'help, 'app, 'parser> {
         );
         let mut ret_val = Vec::new();
 
-        let mut unrolled_reqs = vec![];
+        let mut unrolled_reqs = IndexSet::new();
 
         for a in self.p.required.iter() {
             if let Some(m) = matcher {
                 for aa in self.p.app.unroll_requirements_for_arg(a, m) {
-                    unrolled_reqs.push(aa);
+                    // if we don't check for duplicates here this causes duplicate error messages
+                    // see https://github.com/clap-rs/clap/issues/2770
+                    unrolled_reqs.insert(aa);
                 }
             }
             // always include the required arg itself. it will not be enumerated
             // by unroll_requirements_for_arg.
-            unrolled_reqs.push(a.clone());
+            unrolled_reqs.insert(a.clone());
         }
 
         debug!(

tests/double_require.rs

@@ -0,0 +1,89 @@
+use clap::{App, Arg, ErrorKind};
+
+static HELP: &str = "prog 
+
+USAGE:
+    prog [FLAGS]
+
+FLAGS:
+    -a               
+    -b               
+    -c               
+    -h, --help       Print help information
+    -V, --version    Print version information
+";
+
+static ONLY_B_ERROR: &str = "error: The following required arguments were not provided:
+    -c
+
+USAGE:
+    prog [FLAGS] -c -b
+
+For more information try --help
+";
+
+static ONLY_C_ERROR: &str = "error: The following required arguments were not provided:
+    -b
+
+USAGE:
+    prog [FLAGS] -b -c
+
+For more information try --help
+";
+
+fn app() -> App<'static> {
+    App::new("prog")
+        .arg(
+            Arg::new("a")
+                .short('a')
+                .required_unless_present_any(&["b", "c"])
+                .conflicts_with_all(&["b", "c"]),
+        )
+        .arg(
+            Arg::new("b")
+                .short('b')
+                .required_unless_present("a")
+                .requires("c"),
+        )
+        .arg(
+            Arg::new("c")
+                .short('c')
+                .required_unless_present("a")
+                .requires("b"),
+        )
+}
+
+#[test]
+fn valid_cases() {
+    let res = app().try_get_matches_from(vec!["", "-a"]);
+    assert!(res.is_ok());
+    let res = app().clone().try_get_matches_from(vec!["", "-b", "-c"]);
+    assert!(res.is_ok());
+    let res = app().try_get_matches_from(vec!["", "-c", "-b"]);
+    assert!(res.is_ok());
+}
+
+#[test]
+fn help_text() {
+    let res = app().try_get_matches_from(vec!["prog", "--help"]);
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::DisplayHelp);
+    println!("{}", err.to_string());
+    assert_eq!(err.to_string(), HELP);
+}
+
+#[test]
+fn no_duplicate_error() {
+    let res = app().try_get_matches_from(vec!["", "-b"]);
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::MissingRequiredArgument);
+    assert_eq!(err.to_string(), ONLY_B_ERROR);
+
+    let res = app().try_get_matches_from(vec!["", "-c"]);
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::MissingRequiredArgument);
+    assert_eq!(err.to_string(), ONLY_C_ERROR);
+}