test: Show error when using a binary operator withut two operands

src/uu/test/src/error.rs

@@ -11,6 +11,7 @@ pub enum ParseError {
  MissingArgument(String),
  UnknownOperator(String),
  InvalidInteger(String),
+ UnaryOperatorExpected(String),
 }
 
 /// A Result type for parsing test expressions
@@ -26,6 +27,7 @@ impl std::fmt::Display for ParseError {
  Self::ExtraArgument(s) => write!(f, "extra argument {s}"),
  Self::UnknownOperator(s) => write!(f, "unknown operator {s}"),
  Self::InvalidInteger(s) => write!(f, "invalid integer {s}"),
+ Self::UnaryOperatorExpected(s) => write!(f, "{s}: unary operator expected"),
  }
  }
 }

src/uu/test/src/parser.rs

@@ -8,10 +8,10 @@
 use std::ffi::{OsStr, OsString};
 use std::iter::Peekable;
 
-use super::error::{ParseError, ParseResult};
-
 use uucore::display::Quotable;
 
+use super::error::{ParseError, ParseResult};
+
 /// Represents one of the binary comparison operators for strings, integers, or files
 #[derive(Debug, PartialEq, Eq)]
 pub enum Operator {
@@ -438,3 +438,21 @@ pub fn parse(args: Vec<OsString>) -> ParseResult<Vec<Symbol>> {
  p.parse()?;
  Ok(p.stack)
 }
+
+#[cfg(test)]
+mod tests {
+ use crate::error::ParseError::UnaryOperatorExpected;
+ use crate::eval;
+ use crate::parser::parse;
+
+ #[test]
+ fn unary_expected() {
+ let result = parse(vec!["-o".into(), "arg".into()]).map(|mut x| eval(&mut x));
+
+ if let Ok(Err(UnaryOperatorExpected(s))) = result {
+ assert_eq!(s, "'-o'".to_string());
+ } else {
+ panic!("expected unary operator expected error, not {result:?}")
+ }
+ }
+}

src/uu/test/src/test.rs

@@ -163,6 +163,9 @@ fn eval(stack: &mut Vec<Symbol>) -> ParseResult<bool> {
  Some(Symbol::None) | None => Ok(false),
  Some(Symbol::BoolOp(op)) => {
  let b = eval(stack)?;
+ if stack.is_empty() {
+ return Err(ParseError::UnaryOperatorExpected(op.quote().to_string()));
+ }
  let a = eval(stack)?;
 
  Ok(if op == "-a" { a && b } else { a || b })

tests/by-util/test_test.rs

@@ -67,7 +67,7 @@ fn test_double_not_is_false() {
 
 #[test]
 fn test_and_not_is_false() {
- new_ucmd!().args(&["-a", "!"]).run().code_is(1);
+ new_ucmd!().args(&["-a", "!"]).run().code_is(2);
 }
 
 #[test]