Remove python-like string multiplication (#10293)

# Description
Currently we support "multiplication" of strings, resulting in a terse
way to repeat a particular string.
This can have unintended side effects when dealing with mixed data (e.g.
after parsing data that is not all numbers).
Furthermore as we frequently fall-back to strings while parsing source
code, this introduced a runaway edge case in const evaluation (#10212)

Work for #10233

## Details
- Remove python-like string multiplication.
- Workaround for indentation
  - This should probably be addressed with a purpose built command
- Remove special const-eval error test

# User-Facing Changes
**Major breaking change!**
`"string" * 42` will stop working. (This was used for example in the
stdlib)

We should bless a good alternative before landing this

---------

Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>

crates/nu-command/tests/commands/math/mod.rs

@@ -498,11 +498,3 @@ fn append_binary_values() {
     ));
     assert_eq!(actual.out, "0x[01020304]");
 }
-
-#[test]
-fn int_multiple_string() {
-    let actual = nu!(pipeline(r#"3 * "ab""#));
-    assert_eq!(actual.out, "ababab");
-    let actual = nu!(pipeline(r#""ab" * 3"#));
-    assert_eq!(actual.out, "ababab");
-}

crates/nu-command/tests/commands/parse.rs

@@ -214,14 +214,16 @@ mod regex {
 
     #[test]
     fn parse_handles_external_stream_chunking() {
-        Playground::setup("parse_test_streaming_1", |dirs, _sandbox| {
+        Playground::setup("parse_test_streaming_1", |dirs, sandbox| {
+            let data: String = std::iter::repeat("abcdefghijklmnopqrstuvwxyz")
+                .take(1000)
+                .collect();
+            sandbox.with_files(vec![Stub::FileWithContent("data.txt", &data)]);
+
             let actual = nu!(
-                cwd: dirs.test(), pipeline(
+                cwd: dirs.test(),
-                r#"
+                r#"open data.txt | parse --regex "(abcdefghijklmnopqrstuvwxyz)" | length"#
-                    "abcdefghijklmnopqrstuvwxyz" * 1000 | save --force data.txt;
+            );
-                    open data.txt | parse --regex "(abcdefghijklmnopqrstuvwxyz)" | length
-                "#
-            ));
 
             assert_eq!(actual.out, "1000");
         })

crates/nu-parser/src/type_check.rs

@@ -239,8 +239,6 @@ pub fn math_result_type(
                 (Type::Int, Type::Duration) => (Type::Duration, None),
                 (Type::Duration, Type::Float) => (Type::Duration, None),
                 (Type::Float, Type::Duration) => (Type::Duration, None),
-                (Type::Int, Type::String) => (Type::String, None),
-                (Type::String, Type::Int) => (Type::String, None),
 
                 (Type::Custom(a), Type::Custom(b)) if a == b => (Type::Custom(a.to_string()), None),
                 (Type::Custom(a), _) => (Type::Custom(a.to_string()), None),

crates/nu-protocol/src/eval_const.rs

@@ -415,16 +415,6 @@ pub fn eval_constant(
                     }
                 }
                 Operator::Math(math) => {
-                    match (&math, &lhs.expr, &rhs.expr) {
-                        // Multiple may generate super long string
-                        // and stop the whole shell while highlighting
-                        // e.g. '2 ** 60 * a'
-                        (Math::Multiply, Expr::String(..), _)
-                        | (Math::Multiply, _, Expr::String(..)) => {
-                            return Err(ShellError::NotAConstant(expr.span))
-                        }
-                        _ => {}
-                    }
                     let lhs = eval_constant(working_set, lhs)?;
                     let rhs = eval_constant(working_set, rhs)?;
 

crates/nu-protocol/src/value/mod.rs

@@ -2649,20 +2649,6 @@ impl Value {
             (Value::CustomValue { val: lhs, .. }, rhs) => {
                 lhs.operation(self.span(), Operator::Math(Math::Multiply), op, rhs)
             }
-            (Value::Int { val: lhs, .. }, Value::String { val: rhs, .. }) => {
-                let mut res = String::new();
-                for _ in 0..*lhs {
-                    res.push_str(rhs)
-                }
-                Ok(Value::string(res, span))
-            }
-            (Value::String { val: lhs, .. }, Value::Int { val: rhs, .. }) => {
-                let mut res = String::new();
-                for _ in 0..*rhs {
-                    res.push_str(lhs)
-                }
-                Ok(Value::string(res, span))
-            }
             _ => Err(ShellError::OperatorMismatch {
                 op_span: op,
                 lhs_ty: self.get_type().to_string(),

crates/nu-std/std/testing.nu

@@ -134,7 +134,7 @@ def show-pretty-test [indent: int = 4] {
     let test = $in
 
     [
-        (" " * $indent)
+        (1..$indent | map {" "} | str join)
         (match $test.result {
             "pass" => { ansi green },
             "skip" => { ansi yellow },

tests/const_/mod.rs

@@ -142,7 +142,6 @@ fn const_binary_operator(#[case] inp: &[&str], #[case] expect: &str) {
 #[case(&["const x = 10 ** 10000000", "$x"], "pow operation overflowed")]
 #[case(&["const x = 2 ** 62 * 2", "$x"], "multiply operation overflowed")]
 #[case(&["const x = 1 ++ 0", "$x"], "doesn't support this value")]
-#[case(&["const x = 20 * a", "$x"], "Value is not a parse-time constant")]
 fn const_operator_error(#[case] inp: &[&str], #[case] expect: &str) {
     let actual = nu!(&inp.join("; "));
     assert!(actual.err.contains(expect));