roc/compiler/can/tests/test_can.rs
2020-05-03 08:51:11 -04:00

1298 lines
36 KiB
Rust

#[macro_use]
extern crate pretty_assertions;
#[macro_use]
extern crate indoc;
extern crate bumpalo;
extern crate roc_can;
extern crate roc_parse;
extern crate roc_region;
mod helpers;
#[cfg(test)]
mod test_can {
use crate::helpers::{can_expr_with, test_home, CanExprOut};
use bumpalo::Bump;
use roc_can::expr::Expr::{self, *};
use roc_can::expr::Recursive;
use roc_problem::can::{Problem, RuntimeError};
use roc_region::all::{Located, Region};
use std::{f64, i64};
fn assert_can(input: &str, expected: Expr) {
let arena = Bump::new();
let actual_out = can_expr_with(&arena, test_home(), input);
assert_eq!(actual_out.loc_expr.value, expected);
}
fn assert_can_float(input: &str, expected: f64) {
let arena = Bump::new();
let actual_out = can_expr_with(&arena, test_home(), input);
match actual_out.loc_expr.value {
Expr::Float(_, actual) => {
assert_eq!(expected, actual);
}
actual => {
panic!("Expected a Float, but got: {:?}", actual);
}
}
}
fn assert_can_int(input: &str, expected: i64) {
let arena = Bump::new();
let actual_out = can_expr_with(&arena, test_home(), input);
match actual_out.loc_expr.value {
Expr::Int(_, actual) => {
assert_eq!(expected, actual);
}
actual => {
panic!("Expected an Int, but got: {:?}", actual);
}
}
}
fn assert_can_num(input: &str, expected: i64) {
let arena = Bump::new();
let actual_out = can_expr_with(&arena, test_home(), input);
match actual_out.loc_expr.value {
Expr::Num(_, actual) => {
assert_eq!(expected, actual);
}
actual => {
panic!("Expected a Num, but got: {:?}", actual);
}
}
}
// NUMBER LITERALS
#[test]
fn int_too_large() {
let string = (i64::MAX as i128 + 1).to_string();
assert_can(
&string.clone(),
RuntimeError(RuntimeError::IntOutsideRange(string.into())),
);
}
#[test]
fn int_too_small() {
let string = (i64::MIN as i128 - 1).to_string();
assert_can(
&string.clone(),
RuntimeError(RuntimeError::IntOutsideRange(string.into())),
);
}
#[test]
fn float_too_large() {
let string = format!("{}1.0", f64::MAX);
assert_can(
&string.clone(),
RuntimeError(RuntimeError::FloatOutsideRange(string.into())),
);
}
#[test]
fn float_too_small() {
let string = format!("{}1.0", f64::MIN);
assert_can(
&string.clone(),
RuntimeError(RuntimeError::FloatOutsideRange(string.into())),
);
}
#[test]
fn zero() {
assert_can_num("0", 0);
}
#[test]
fn minus_zero() {
assert_can_num("-0", 0);
}
#[test]
fn zero_point_zero() {
assert_can_float("0.0", 0.0);
}
#[test]
fn minus_zero_point_zero() {
assert_can_float("-0.0", -0.0);
}
#[test]
fn hex_zero() {
assert_can_int("0x0", 0x0);
}
#[test]
fn hex_one_b() {
assert_can_int("0x1b", 0x1b);
}
#[test]
fn minus_hex_one_b() {
assert_can_int("-0x1b", -0x1b);
}
#[test]
fn octal_zero() {
assert_can_int("0o0", 0o0);
}
#[test]
fn octal_one_two() {
assert_can_int("0o12", 0o12);
}
#[test]
fn minus_octal_one_two() {
assert_can_int("-0o12", -0o12);
}
#[test]
fn binary_zero() {
assert_can_int("0b0", 0b0);
}
#[test]
fn binary_one_one() {
assert_can_int("0b11", 0b11);
}
#[test]
fn minus_binary_one_one() {
assert_can_int("-0b11", -0b11);
}
// LOCALS
// TODO rewrite this test to check only for UnusedDef reports
// #[test]
// fn closure_args_are_not_locals() {
// // "arg" shouldn't make it into output.locals, because
// // it only exists in the closure's arguments.
// let arena = Bump::new();
// let src = indoc!(
// r#"
// func = \arg -> arg
// func 2
// "#
// );
// let (_actual, output, problems, _var_store, _vars, _constraint) =
// can_expr_with(&arena, test_home(), src);
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["func"],
// calls: vec!["func"],
// tail_call: None
// }
// .into_output(scope)
// );
// }
// TODO rewrite this test to check only for UnusedDef reports
// #[test]
// fn call_by_pointer_for_fn_args() {
// // This function will get passed in as a pointer.
// let src = indoc!(
// r#"
// apply = \f, x -> f x
// identity = \a -> a
// apply identity 5
// "#
// );
// let arena = Bump::new();
// let (_actual, output, problems, _var_store, _vars, _constraint) =
// can_expr_with(&arena, test_home(), src);
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["identity", "apply"],
// calls: vec!["f", "apply"],
// tail_call: None
// }
// .into()
// );
// }
fn get_closure(expr: &Expr, i: usize) -> roc_can::expr::Recursive {
match expr {
LetRec(assignments, body, _, _) => {
match &assignments.get(i).map(|def| &def.loc_expr.value) {
Some(Closure(_, _, recursion, _, _)) => recursion.clone(),
Some(other @ _) => {
panic!("assignment at {} is not a closure, but a {:?}", i, other)
}
None => {
if i > 0 {
get_closure(&body.value, i - 1)
} else {
panic!("Looking for assignment at {} but the list is too short", i)
}
}
}
}
LetNonRec(def, body, _, _) => {
if i > 0 {
// recurse in the body (not the def!)
get_closure(&body.value, i - 1)
} else {
match &def.loc_expr.value {
Closure(_, _, recursion, _, _) => recursion.clone(),
other @ _ => {
panic!("assignment at {} is not a closure, but a {:?}", i, other)
}
}
}
}
// Closure(_, recursion, _, _) if i == 0 => recursion.clone(),
_ => panic!(
"expression is not a LetRec or a LetNonRec, but rather {:?}",
expr
),
}
}
#[test]
fn recognize_tail_calls() {
let src = indoc!(
r#"
g = \x ->
when x is
0 -> 0
_ -> g (x - 1)
# use parens to force the ordering!
(h = \x ->
when x is
0 -> 0
_ -> g (x - 1)
(p = \x ->
when x is
0 -> 0
1 -> g (x - 1)
_ -> p (x - 1)
# variables must be (indirectly) referenced in the body for analysis to work
{ x: p, y: h }
))
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
assert!(problems.iter().all(|problem| match problem {
Problem::UnusedDef(_, _) => true,
_ => false,
}));
let actual = loc_expr.value;
let g_detected = get_closure(&actual, 0);
let h_detected = get_closure(&actual, 1);
let p_detected = get_closure(&actual, 2);
assert_eq!(g_detected, Recursive::TailRecursive);
assert_eq!(h_detected, Recursive::NotRecursive);
assert_eq!(p_detected, Recursive::TailRecursive);
}
// TODO restore this test! It should report two unused defs (h and p), but only reports 1.
// #[test]
// fn reproduce_incorrect_unused_defs() {
// let src = indoc!(
// r#"
// g = \x ->
// when x is
// 0 -> 0
// _ -> g (x - 1)
// h = \x ->
// when x is
// 0 -> 0
// _ -> g (x - 1)
// p = \x ->
// when x is
// 0 -> 0
// 1 -> g (x - 1)
// _ -> p (x - 1)
// # variables must be (indirectly) referenced in the body for analysis to work
// # { x: p, y: h }
// g
// "#
// );
// let arena = Bump::new();
// let CanExprOut {
// loc_expr, problems, ..
// } = can_expr_with(&arena, test_home(), src);
// // There should be two UnusedDef problems: one for h, and one for p
// assert_eq!(problems.len(), 2);
// assert!(problems.iter().all(|problem| match problem {
// Problem::UnusedDef(_, _) => true,
// _ => false,
// }));
// let actual = loc_expr.value;
// // NOTE: the indices associated with each of these can change!
// // They come out of a hashmap, and are not sorted.
// let g_detected = get_closure(&actual, 0);
// let h_detected = get_closure(&actual, 2);
// let p_detected = get_closure(&actual, 1);
// assert_eq!(g_detected, Recursive::TailRecursive);
// assert_eq!(h_detected, Recursive::NotRecursive);
// assert_eq!(p_detected, Recursive::TailRecursive);
// }
#[test]
fn when_tail_call() {
let src = indoc!(
r#"
g = \x ->
when x is
0 -> 0
_ -> g (x + 1)
g 0
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
let detected = get_closure(&loc_expr.value, 0);
assert_eq!(detected, Recursive::TailRecursive);
}
#[test]
fn immediate_tail_call() {
let src = indoc!(
r#"
f = \x -> f x
f 0
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
let detected = get_closure(&loc_expr.value, 0);
assert_eq!(detected, Recursive::TailRecursive);
}
#[test]
fn when_condition_is_no_tail_call() {
let src = indoc!(
r#"
q = \x ->
when q x is
_ -> 0
q 0
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
let detected = get_closure(&loc_expr.value, 0);
assert_eq!(detected, Recursive::Recursive);
}
#[test]
fn good_mutual_recursion() {
let src = indoc!(
r#"
q = \x ->
when x is
0 -> 0
_ -> p (x - 1)
p = \x ->
when x is
0 -> 0
_ -> q (x - 1)
q p
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
let actual = loc_expr.value;
let detected = get_closure(&actual, 0);
assert_eq!(detected, Recursive::Recursive);
let detected = get_closure(&actual, 1);
assert_eq!(detected, Recursive::Recursive);
}
#[test]
fn valid_self_recursion() {
let src = indoc!(
r#"
boom = \_ -> boom {}
boom
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
let is_circular_def = if let RuntimeError(RuntimeError::CircularDef(_, _)) = loc_expr.value
{
true
} else {
false
};
assert_eq!(is_circular_def, false);
}
#[test]
fn invalid_self_recursion() {
let src = indoc!(
r#"
x = x
x
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
let is_circular_def = if let RuntimeError(RuntimeError::CircularDef(_, _)) = loc_expr.value
{
true
} else {
false
};
let problem = Problem::RuntimeError(RuntimeError::CircularDef(
vec![Located::at(Region::new(0, 0, 0, 1), "x".into())],
vec![(Region::new(0, 0, 0, 1), Region::new(0, 0, 4, 5))],
));
assert_eq!(is_circular_def, true);
assert_eq!(problems, vec![problem]);
}
#[test]
fn invalid_mutual_recursion() {
let src = indoc!(
r#"
x = y
y = z
z = x
x
"#
);
let arena = Bump::new();
let CanExprOut {
loc_expr, problems, ..
} = can_expr_with(&arena, test_home(), src);
let problem = Problem::RuntimeError(RuntimeError::CircularDef(
vec![
Located::at(Region::new(0, 0, 0, 1), "x".into()),
Located::at(Region::new(1, 1, 0, 1), "y".into()),
Located::at(Region::new(2, 2, 0, 1), "z".into()),
],
vec![
(Region::new(0, 0, 0, 1), Region::new(0, 0, 4, 5)),
(Region::new(1, 1, 0, 1), Region::new(1, 1, 4, 5)),
(Region::new(2, 2, 0, 1), Region::new(2, 2, 4, 5)),
],
));
assert_eq!(problems, vec![problem]);
match loc_expr.value {
RuntimeError(RuntimeError::CircularDef(_, _)) => (),
actual => {
panic!("Expected a CircularDef runtime error, but got {:?}", actual);
}
}
}
#[test]
fn unused_def_regression() {
let src = indoc!(
r#"
Booly : [ Yes, No, Maybe ]
y : Booly
y = No
# There was a bug where annotating a def meant that its
# references no longer got reported.
#
# https://github.com/rtfeldman/roc/issues/298
x : List Booly
x = [ y ]
x
"#
);
let arena = Bump::new();
let CanExprOut { problems, .. } = can_expr_with(&arena, test_home(), src);
assert_eq!(problems, Vec::new());
}
//#[test]
//fn closing_over_locals() {
// // "local" should be used, because the closure used it.
// // However, "unused" should be unused.
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// local = 5
// unused = 6
// func = \arg -> arg + local
// 3 + func 2
// "#
// ));
// assert_eq!(
// problems,
// vec![Problem::UnusedAssignment(loc((
// "unused".to_string()
// )))]
// );
// assert_eq!(
// output,
// Out {
// lookups: vec!["func", "local"],
// calls: vec!["func"],
// tail_call: None
// }
// .into()
// );
//}
//#[test]
//fn unused_closure() {
// // "unused" should be unused because it's in func, which is unused.
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// local = 5
// unused = 6
// func = \arg -> arg + unused
// local
// "#
// ));
// assert_eq!(
// problems,
// vec![
// Problem::UnusedAssignment(loc(("unused".to_string()))),
// Problem::UnusedAssignment(loc(("func".to_string()))),
// ]
// );
// assert_eq!(
// output,
// Out {
// lookups: vec!["local"],
// calls: vec![],
// tail_call: None
// }
// .into()
// );
//}
// // UNRECOGNIZED
// #[test]
// fn basic_unrecognized_constant() {
// let (expr, output, problems, _) = can_expr(indoc!(
// r#"
// x
// "#
// ));
// assert_eq!(
// problems,
// vec![Problem::LookupNotInScope(loc(("x".to_string())))]
// );
// assert_eq!(expr, LookupNotInScope(loc(("x".to_string()))));
// assert_eq!(
// output,
// Out {
// lookups: vec![],
// calls: vec![],
// tail_call: None
// }
// .into()
// );
// }
//#[test]
//fn complex_unrecognized_constant() {
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// a = 5
// b = 6
// a + b * z
// "#
// ));
// assert_eq!(
// problems,
// vec![Problem::LookupNotInScope(loc((
// "z".to_string()
// )))]
// );
// assert_eq!(
// output,
// Out {
// lookups: vec!["a", "b"],
// calls: vec![],
// tail_call: None
// }
// .into()
// );
//}
//// UNUSED
//#[test]
//fn mutual_unused_circular_vars() {
// // This should report that both a and b are unused, since the return expr never references them.
// // It should not report them as circular, since we haven't solved the halting problem here.
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// a = \arg -> if arg > 0 then b 7 else 0
// b = \arg -> if arg > 0 then a (arg - 1) else 0
// c = 5
// c
// "#
// ));
// assert_eq!(problems, vec![unused("a"), unused("b")]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["c"],
// calls: vec![],
// tail_call: None
// }
// .into()
// );
//}
//#[test]
//fn can_fibonacci() {
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// fibonacci = \num ->
// if num < 2 then
// num
// else
// fibonacci (num - 1) + fibonacci (num - 2)
// fibonacci 9
// "#
// ));
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["fibonacci"],
// calls: vec!["fibonacci"],
// tail_call: None
// }
// .into()
// );
//}
//#[test]
//fn can_tail_call() {
// // TODO check the global params - make sure this
// // is considered a tail call, even though it only
// // calls itself from one branch!
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// factorial = \num ->
// factorialHelp num 0
// factorialHelp = \num total ->
// if num == 0 then
// total
// else
// factorialHelp (num - 1) (total * num)
// factorial 9
// "#
// ));
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["factorial", "factorialHelp"],
// calls: vec!["factorial", "factorialHelp"],
// tail_call: None
// }
// .into()
// );
//}
//#[test]
//fn transitively_used_function() {
// // This should report that neither a nor b are unused,
// // since if you never call a function but do return it, that's okay!
// let (_, output, problems, _) = can_expr(indoc!(
// r#"
// a = \_ -> 42
// b = a
// b
// "#
// ));
// assert_eq!(problems, Vec::new());
// assert_eq!(
// output,
// Out {
// lookups: vec!["a", "b"],
// calls: vec![],
// tail_call: None
// }
// .into()
// );
//}
//// ASSIGNMENT REORDERING
//#[test]
//fn reorder_assignments() {
// let (expr, output, problems, _) = can_expr(indoc!(
// r#"
// increment = \arg -> arg + 1
// z = (increment 2) + y
// y = x + 1
// x = 9
// z * 3
// "#
// ));
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["increment", "x", "y", "z"],
// calls: vec!["increment"],
// tail_call: None
// }
// .into()
// );
// let symbols = assigned_symbols(expr);
// // In code gen, for everything to have been set before it gets read,
// // the following must be true about when things are assigned:
// //
// // x must be assigned before y
// // y must be assigned before z
// //
// // The order of the increment function doesn't matter.
// assert_before("x", "y", &symbols);
// assert_before("y", "z", &symbols);
//}
//#[test]
//fn reorder_closed_over_assignments() {
// let (expr, output, problems, _) = can_expr(indoc!(
// r#"
// z = func1 x
// x = 9
// y = func2 3
// func1 = \arg -> func2 arg + y
// func2 = \arg -> arg + x
// z
// "#
// ));
// assert_eq!(problems, vec![]);
// assert_eq!(
// output,
// Out {
// lookups: vec!["func1", "func2", "x", "y", "z"],
// calls: vec!["func1", "func2"],
// tail_call: None
// }
// .into()
// );
// let symbols = assigned_symbols(expr);
// // In code gen, for everything to have been set before it gets read,
// // the following must be true about when things are assigned:
// //
// // x and func2 must be assigned (in either order) before y
// // y and func1 must be assigned (in either order) before z
// assert_before("x", "y", &symbols);
// assert_before("func2", "y", &symbols);
// assert_before("func1", "z", &symbols);
// assert_before("y", "z", &symbols);
//}
//fn assert_before(before: &str, after: &str, symbols: &Vec<Symbol>) {
// assert_ne!(before, after);
// let before_symbol = sym(before);
// let after_symbol = sym(after);
// let before_index = symbols
// .iter()
// .position(|symbol| symbol == &before_symbol)
// .unwrap_or_else(|| {
// panic!(
// "error in assert_before({:?}, {:?}): {:?} could not be found in {:?}",
// before,
// after,
// sym(before),
// symbols
// )
// });
// let after_index = symbols
// .iter()
// .position(|symbol| symbol == &after_symbol)
// .unwrap_or_else(|| {
// panic!(
// "error in assert_before({:?}, {:?}): {:?} could not be found in {:?}",
// before,
// after,
// sym(after),
// symbols
// )
// });
// if before_index == after_index {
// panic!(
// "error in assert_before({:?}, {:?}): both were at index {} in {:?}",
// before, after, after_index, symbols
// );
// } else if before_index > after_index {
// panic!("error in assert_before: {:?} appeared *after* {:?} (not before, as expected) in {:?}", before, after, symbols);
// }
//}
//fn assigned_symbols(expr: Expr) -> Vec<Symbol> {
// match expr {
// Assign(assignments, _) => {
// assignments.into_iter().map(|(pattern, _)| {
// match pattern.value {
// Identifier(symbol) => {
// symbol
// },
// _ => {
// panic!("Called assigned_symbols passing an Assign expr with non-Identifier patterns!");
// }
// }
// }).collect()
// },
// _ => {
// panic!("Called assigned_symbols passing a non-Assign expr!");
// }
// }
//}
//// CIRCULAR ASSIGNMENT
//#[test]
//fn circular_assignment() {
// let (_, _, problems, _) = can_expr(indoc!(
// r#"
// c = d + 3
// b = 2 + c
// d = a + 7
// a = b + 1
// 2 + d
// "#
// ));
// assert_eq!(
// problems,
// vec![Problem::CircularAssignment(vec![
// // c should appear first because it's assigned first in the original expression.
// loc(unqualified("c")),
// loc(unqualified("d")),
// loc(unqualified("a")),
// loc(unqualified("b")),
// ])]
// );
//}
//#[test]
//fn always_function() {
// // There was a bug where this reported UnusedArgument("val")
// // since it was used only in the returned function only.
// let (_, _, problems, _) = can_expr(indoc!(
// r#"
// \val -> \_ -> val
// "#
// ));
// assert_eq!(problems, vec![]);
//}
//// TODO verify that Apply handles output.references.calls correctly
//// UNSUPPORTED PATTERNS
//// TODO verify that in closures and assignments, you can't assign to int/string/underscore/etc
//// OPERATOR PRECEDENCE
//// fn parse_with_precedence(input: &str) -> Result<(Expr, &str), easy::Errors<char, &str, IndentablePosition>> {
//// parse_without_loc(input)
//// .map(|(expr, remaining)| (expr::apply_precedence_and_associativity(loc(expr)).unwrap().value, remaining))
//// }
//// #[test]
//// fn two_operator_precedence() {
//// assert_eq!(
//// parse_with_precedence("x + y * 5"),
//// Ok((BinOp(
//// loc_box(var("x")),
//// loc(Plus),
//// loc_box(
//// BinOp(
//// loc_box(var("y")),
//// loc(Star),
//// loc_box(Int(5))
//// )
//// ),
//// ),
//// ""))
//// );
//// assert_eq!(
//// parse_with_precedence("x * y + 5"),
//// Ok((BinOp(
//// loc_box(
//// BinOp(
//// loc_box(var("x")),
//// loc(Star),
//// loc_box(var("y")),
//// )
//// ),
//// loc(Plus),
//// loc_box(Int(5))
//// ),
//// ""))
//// );
//// }
//// #[test]
//// fn compare_and() {
//// assert_eq!(
//// parse_with_precedence("x > 1 || True"),
//// Ok((BinOp(
//// loc_box(
//// BinOp(
//// loc_box(var("x")),
//// loc(GreaterThan),
//// loc_box(Int(1))
//// )
//// ),
//// loc(Or),
//// loc_box(ApplyVariant(vname("True"), None))
//// ),
//// ""))
//// );
//// }
//// HELPERS
//#[test]
//fn sort_cyclic_idents() {
// let assigned_idents = unqualifieds(vec!["blah", "c", "b", "d", "a"]);
// assert_eq!(
// can::sort_cyclic_idents(
// loc_unqualifieds(vec!["a", "b", "c", "d"]),
// &mut assigned_idents.iter()
// ),
// loc_unqualifieds(vec!["c", "d", "a", "b"])
// );
//}
//
//
//// STRING LITERALS
//
// #[test]
// fn string_with_valid_unicode_escapes() {
// expect_parsed_str("x\u{00A0}x", r#""x\u{00A0}x""#);
// expect_parsed_str("x\u{101010}x", r#""x\u{101010}x""#);
// }
// #[test]
// fn string_with_too_large_unicode_escape() {
// // Should be too big - max size should be 10FFFF.
// // (Rust has this restriction. I assume it's a good idea.)
// assert_malformed_str(
// r#""abc\u{110000}def""#,
// vec![Located::new(0, 7, 0, 12, Problem::UnicodeCodePointTooLarge)],
// );
// }
// #[test]
// fn string_with_no_unicode_digits() {
// // No digits specified
// assert_malformed_str(
// r#""blah\u{}foo""#,
// vec![Located::new(0, 5, 0, 8, Problem::NoUnicodeDigits)],
// );
// }
// #[test]
// fn string_with_no_unicode_opening_brace() {
// // No opening curly brace. It can't be sure if the closing brace
// // was intended to be a closing brace for the unicode escape, so
// // report that there were no digits specified.
// assert_malformed_str(
// r#""abc\u00A0}def""#,
// vec![Located::new(0, 4, 0, 5, Problem::NoUnicodeDigits)],
// );
// }
// #[test]
// fn string_with_no_unicode_closing_brace() {
// // No closing curly brace
// assert_malformed_str(
// r#""blah\u{stuff""#,
// vec![Located::new(0, 5, 0, 12, Problem::MalformedEscapedUnicode)],
// );
// }
// #[test]
// fn string_with_no_unicode_braces() {
// // No curly braces
// assert_malformed_str(
// r#""zzzz\uzzzzz""#,
// vec![Located::new(0, 5, 0, 6, Problem::NoUnicodeDigits)],
// );
// }
// #[test]
// fn string_with_interpolation_at_start() {
// let input = indoc!(
// r#"
// "\(abc)defg"
// "#
// );
// let (args, ret) = (vec![("", Located::new(0, 2, 0, 4, Var("abc")))], "defg");
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(InterpolatedStr(&(arena.alloc_slice_clone(&args), ret))),
// actual
// );
// }
// #[test]
// fn string_with_interpolation_at_end() {
// let input = indoc!(
// r#"
// "abcd\(efg)"
// "#
// );
// let (args, ret) = (vec![("abcd", Located::new(0, 6, 0, 8, Var("efg")))], "");
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(InterpolatedStr(&(arena.alloc_slice_clone(&args), ret))),
// actual
// );
// }
// #[test]
// fn string_with_interpolation_in_middle() {
// let input = indoc!(
// r#"
// "abc\(defg)hij"
// "#
// );
// let (args, ret) = (vec![("abc", Located::new(0, 5, 0, 8, Var("defg")))], "hij");
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(InterpolatedStr(&(arena.alloc_slice_clone(&args), ret))),
// actual
// );
// }
// #[test]
// fn string_with_two_interpolations_in_middle() {
// let input = indoc!(
// r#"
// "abc\(defg)hi\(jkl)mn"
// "#
// );
// let (args, ret) = (
// vec![
// ("abc", Located::new(0, 5, 0, 8, Var("defg"))),
// ("hi", Located::new(0, 14, 0, 16, Var("jkl"))),
// ],
// "mn",
// );
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(InterpolatedStr(&(arena.alloc_slice_clone(&args), ret))),
// actual
// );
// }
// #[test]
// fn string_with_four_interpolations() {
// let input = indoc!(
// r#"
// "\(abc)def\(ghi)jkl\(mno)pqrs\(tuv)"
// "#
// );
// let (args, ret) = (
// vec![
// ("", Located::new(0, 2, 0, 4, Var("abc"))),
// ("def", Located::new(0, 11, 0, 13, Var("ghi"))),
// ("jkl", Located::new(0, 20, 0, 22, Var("mno"))),
// ("pqrs", Located::new(0, 30, 0, 32, Var("tuv"))),
// ],
// "",
// );
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(InterpolatedStr(&(arena.alloc_slice_clone(&args), ret))),
// actual
// );
// }
// #[test]
// fn string_with_escaped_interpolation() {
// assert_parses_to(
// // This should NOT be string interpolation, because of the \\
// indoc!(
// r#"
// "abcd\\(efg)hij"
// "#
// ),
// Str(r#"abcd\(efg)hij"#.into()),
// );
// }
//
// #[test]
// fn string_without_escape() {
// expect_parsed_str("a", r#""a""#);
// expect_parsed_str("ab", r#""ab""#);
// expect_parsed_str("abc", r#""abc""#);
// expect_parsed_str("123", r#""123""#);
// expect_parsed_str("abc123", r#""abc123""#);
// expect_parsed_str("123abc", r#""123abc""#);
// expect_parsed_str("123 abc 456 def", r#""123 abc 456 def""#);
// }
// #[test]
// fn string_with_special_escapes() {
// expect_parsed_str(r#"x\x"#, r#""x\\x""#);
// expect_parsed_str(r#"x"x"#, r#""x\"x""#);
// expect_parsed_str("x\tx", r#""x\tx""#);
// expect_parsed_str("x\rx", r#""x\rx""#);
// expect_parsed_str("x\nx", r#""x\nx""#);
// }
// fn assert_malformed_str<'a>(input: &'a str, expected_probs: Vec<Located<Problem>>) {
// let arena = Bump::new();
// let actual = parse_with(&arena, input);
// assert_eq!(
// Ok(Expr::MalformedStr(expected_probs.into_boxed_slice())),
// actual
// );
// }
//
// TODO test what happens when interpolated strings contain 1+ malformed idents
//
// TODO test hex/oct/binary conversion to numbers
//
// TODO test for \t \r and \n in string literals *outside* unicode escape sequence!
}