rust/crates/ra_text_edit/src/test_utils.rs

115 lines
3.4 KiB
Rust

use proptest::prelude::*;
use text_unit::{TextUnit, TextRange};
use crate::AtomTextEdit;
pub fn arb_text() -> proptest::string::RegexGeneratorStrategy<String> {
// generate multiple newlines
proptest::string::string_regex("(.*\n?)*").unwrap()
}
fn text_offsets(text: &str) -> Vec<TextUnit> {
text.char_indices()
.map(|(i, _)| TextUnit::from_usize(i))
.collect()
}
pub fn arb_offset(text: &str) -> BoxedStrategy<TextUnit> {
let offsets = text_offsets(text);
// this is necessary to avoid "Uniform::new called with `low >= high`" panic
if offsets.is_empty() {
Just(TextUnit::from(0)).boxed()
} else {
prop::sample::select(offsets).boxed()
}
}
pub fn arb_edits(text: &str) -> BoxedStrategy<Vec<AtomTextEdit>> {
if text.is_empty() {
// only valid edits
return Just(vec![])
.boxed()
.prop_union(
arb_text()
.prop_map(|text| vec![AtomTextEdit::insert(TextUnit::from(0), text)])
.boxed(),
)
.boxed();
}
let offsets = text_offsets(text);
let max_cuts = offsets.len().min(7);
proptest::sample::subsequence(offsets, 0..max_cuts)
.prop_flat_map(|cuts| {
let strategies: Vec<_> = cuts
.chunks(2)
.map(|chunk| match chunk {
&[from, to] => {
let range = TextRange::from_to(from, to);
Just(AtomTextEdit::delete(range))
.boxed()
.prop_union(
arb_text()
.prop_map(move |text| AtomTextEdit::replace(range, text))
.boxed(),
)
.boxed()
}
&[x] => arb_text()
.prop_map(move |text| AtomTextEdit::insert(x, text))
.boxed(),
_ => unreachable!(),
})
.collect();
strategies
})
.boxed()
}
#[cfg(test)]
mod tests {
use super::*;
use proptest::{proptest, proptest_helper};
fn arb_text_with_edits() -> BoxedStrategy<(String, Vec<AtomTextEdit>)> {
let text = arb_text();
text.prop_flat_map(|s| {
let edits = arb_edits(&s);
(Just(s), edits)
})
.boxed()
}
fn intersect(r1: TextRange, r2: TextRange) -> Option<TextRange> {
let start = r1.start().max(r2.start());
let end = r1.end().min(r2.end());
if start <= end {
Some(TextRange::from_to(start, end))
} else {
None
}
}
proptest! {
#[test]
fn atom_text_edits_are_valid((text, edits) in arb_text_with_edits()) {
proptest_atom_text_edits_are_valid(text, edits)
}
}
fn proptest_atom_text_edits_are_valid(text: String, edits: Vec<AtomTextEdit>) {
// slicing doesn't panic
for e in &edits {
let _ = &text[e.delete];
}
// ranges do not overlap
for i in 1..edits.len() {
let e1 = &edits[i];
for e2 in &edits[0..i] {
if intersect(e1.delete, e2.delete).is_some() {
assert!(false, "Overlapping ranges {} {}", e1.delete, e2.delete);
}
}
}
}
}