rust/crates/test-utils/src/lib.rs
2022-07-24 10:38:19 +02:00

501 lines
16 KiB
Rust

//! Assorted testing utilities.
//!
//! Most notable things are:
//!
//! * Rich text comparison, which outputs a diff.
//! * Extracting markup (mainly, `$0` markers) out of fixture strings.
//! * marks (see the eponymous module).
#![warn(rust_2018_idioms, unused_lifetimes, semicolon_in_expressions_from_macros)]
mod assert_linear;
pub mod bench_fixture;
mod fixture;
use std::{
collections::BTreeMap,
env, fs,
path::{Path, PathBuf},
};
use profile::StopWatch;
use stdx::is_ci;
use text_size::{TextRange, TextSize};
pub use dissimilar::diff as __diff;
pub use rustc_hash::FxHashMap;
pub use crate::{
assert_linear::AssertLinear,
fixture::{Fixture, MiniCore},
};
pub const CURSOR_MARKER: &str = "$0";
pub const ESCAPED_CURSOR_MARKER: &str = "\\$0";
/// Asserts that two strings are equal, otherwise displays a rich diff between them.
///
/// The diff shows changes from the "original" left string to the "actual" right string.
///
/// All arguments starting from and including the 3rd one are passed to
/// `eprintln!()` macro in case of text inequality.
#[macro_export]
macro_rules! assert_eq_text {
($left:expr, $right:expr) => {
assert_eq_text!($left, $right,)
};
($left:expr, $right:expr, $($tt:tt)*) => {{
let left = $left;
let right = $right;
if left != right {
if left.trim() == right.trim() {
std::eprintln!("Left:\n{:?}\n\nRight:\n{:?}\n\nWhitespace difference\n", left, right);
} else {
let diff = $crate::__diff(left, right);
std::eprintln!("Left:\n{}\n\nRight:\n{}\n\nDiff:\n{}\n", left, right, $crate::format_diff(diff));
}
std::eprintln!($($tt)*);
panic!("text differs");
}
}};
}
/// Infallible version of `try_extract_offset()`.
pub fn extract_offset(text: &str) -> (TextSize, String) {
match try_extract_offset(text) {
None => panic!("text should contain cursor marker"),
Some(result) => result,
}
}
/// Returns the offset of the first occurrence of `$0` marker and the copy of `text`
/// without the marker.
fn try_extract_offset(text: &str) -> Option<(TextSize, String)> {
let cursor_pos = text.find(CURSOR_MARKER)?;
let mut new_text = String::with_capacity(text.len() - CURSOR_MARKER.len());
new_text.push_str(&text[..cursor_pos]);
new_text.push_str(&text[cursor_pos + CURSOR_MARKER.len()..]);
let cursor_pos = TextSize::from(cursor_pos as u32);
Some((cursor_pos, new_text))
}
/// Infallible version of `try_extract_range()`.
pub fn extract_range(text: &str) -> (TextRange, String) {
match try_extract_range(text) {
None => panic!("text should contain cursor marker"),
Some(result) => result,
}
}
/// Returns `TextRange` between the first two markers `$0...$0` and the copy
/// of `text` without both of these markers.
fn try_extract_range(text: &str) -> Option<(TextRange, String)> {
let (start, text) = try_extract_offset(text)?;
let (end, text) = try_extract_offset(&text)?;
Some((TextRange::new(start, end), text))
}
#[derive(Clone, Copy)]
pub enum RangeOrOffset {
Range(TextRange),
Offset(TextSize),
}
impl RangeOrOffset {
pub fn expect_offset(self) -> TextSize {
match self {
RangeOrOffset::Offset(it) => it,
RangeOrOffset::Range(_) => panic!("expected an offset but got a range instead"),
}
}
pub fn expect_range(self) -> TextRange {
match self {
RangeOrOffset::Range(it) => it,
RangeOrOffset::Offset(_) => panic!("expected a range but got an offset"),
}
}
pub fn range_or_empty(self) -> TextRange {
match self {
RangeOrOffset::Range(range) => range,
RangeOrOffset::Offset(offset) => TextRange::empty(offset),
}
}
}
impl From<RangeOrOffset> for TextRange {
fn from(selection: RangeOrOffset) -> Self {
match selection {
RangeOrOffset::Range(it) => it,
RangeOrOffset::Offset(it) => TextRange::empty(it),
}
}
}
/// Extracts `TextRange` or `TextSize` depending on the amount of `$0` markers
/// found in `text`.
///
/// # Panics
/// Panics if no `$0` marker is present in the `text`.
pub fn extract_range_or_offset(text: &str) -> (RangeOrOffset, String) {
if let Some((range, text)) = try_extract_range(text) {
return (RangeOrOffset::Range(range), text);
}
let (offset, text) = extract_offset(text);
(RangeOrOffset::Offset(offset), text)
}
/// Extracts ranges, marked with `<tag> </tag>` pairs from the `text`
pub fn extract_tags(mut text: &str, tag: &str) -> (Vec<(TextRange, Option<String>)>, String) {
let open = format!("<{}", tag);
let close = format!("</{}>", tag);
let mut ranges = Vec::new();
let mut res = String::new();
let mut stack = Vec::new();
loop {
match text.find('<') {
None => {
res.push_str(text);
break;
}
Some(i) => {
res.push_str(&text[..i]);
text = &text[i..];
if text.starts_with(&open) {
let close_open = text.find('>').unwrap();
let attr = text[open.len()..close_open].trim();
let attr = if attr.is_empty() { None } else { Some(attr.to_string()) };
text = &text[close_open + '>'.len_utf8()..];
let from = TextSize::of(&res);
stack.push((from, attr));
} else if text.starts_with(&close) {
text = &text[close.len()..];
let (from, attr) =
stack.pop().unwrap_or_else(|| panic!("unmatched </{}>", tag));
let to = TextSize::of(&res);
ranges.push((TextRange::new(from, to), attr));
} else {
res.push('<');
text = &text['<'.len_utf8()..];
}
}
}
}
assert!(stack.is_empty(), "unmatched <{}>", tag);
ranges.sort_by_key(|r| (r.0.start(), r.0.end()));
(ranges, res)
}
#[test]
fn test_extract_tags() {
let (tags, text) = extract_tags(r#"<tag fn>fn <tag>main</tag>() {}</tag>"#, "tag");
let actual = tags.into_iter().map(|(range, attr)| (&text[range], attr)).collect::<Vec<_>>();
assert_eq!(actual, vec![("fn main() {}", Some("fn".into())), ("main", None),]);
}
/// Inserts `$0` marker into the `text` at `offset`.
pub fn add_cursor(text: &str, offset: TextSize) -> String {
let offset: usize = offset.into();
let mut res = String::new();
res.push_str(&text[..offset]);
res.push_str("$0");
res.push_str(&text[offset..]);
res
}
/// Extracts `//^^^ some text` annotations.
///
/// A run of `^^^` can be arbitrary long and points to the corresponding range
/// in the line above.
///
/// The `// ^file text` syntax can be used to attach `text` to the entirety of
/// the file.
///
/// Multiline string values are supported:
///
/// // ^^^ first line
/// // | second line
///
/// Trailing whitespace is sometimes desired but usually stripped by the editor
/// if at the end of a line, or incorrectly sized if followed by another
/// annotation. In those cases the annotation can be explicitly ended with the
/// `$` character.
///
/// // ^^^ trailing-ws-wanted $
///
/// Annotations point to the last line that actually was long enough for the
/// range, not counting annotations themselves. So overlapping annotations are
/// possible:
/// ```no_run
/// // stuff other stuff
/// // ^^ 'st'
/// // ^^^^^ 'stuff'
/// // ^^^^^^^^^^^ 'other stuff'
/// ```
pub fn extract_annotations(text: &str) -> Vec<(TextRange, String)> {
let mut res = Vec::new();
// map from line length to beginning of last line that had that length
let mut line_start_map = BTreeMap::new();
let mut line_start: TextSize = 0.into();
let mut prev_line_annotations: Vec<(TextSize, usize)> = Vec::new();
for line in text.split_inclusive('\n') {
let mut this_line_annotations = Vec::new();
let line_length = if let Some((prefix, suffix)) = line.split_once("//") {
let ss_len = TextSize::of("//");
let annotation_offset = TextSize::of(prefix) + ss_len;
for annotation in extract_line_annotations(suffix.trim_end_matches('\n')) {
match annotation {
LineAnnotation::Annotation { mut range, content, file } => {
range += annotation_offset;
this_line_annotations.push((range.end(), res.len()));
let range = if file {
TextRange::up_to(TextSize::of(text))
} else {
let line_start = line_start_map.range(range.end()..).next().unwrap();
range + line_start.1
};
res.push((range, content));
}
LineAnnotation::Continuation { mut offset, content } => {
offset += annotation_offset;
let &(_, idx) = prev_line_annotations
.iter()
.find(|&&(off, _idx)| off == offset)
.unwrap();
res[idx].1.push('\n');
res[idx].1.push_str(&content);
res[idx].1.push('\n');
}
}
}
annotation_offset
} else {
TextSize::of(line)
};
line_start_map = line_start_map.split_off(&line_length);
line_start_map.insert(line_length, line_start);
line_start += TextSize::of(line);
prev_line_annotations = this_line_annotations;
}
res
}
enum LineAnnotation {
Annotation { range: TextRange, content: String, file: bool },
Continuation { offset: TextSize, content: String },
}
fn extract_line_annotations(mut line: &str) -> Vec<LineAnnotation> {
let mut res = Vec::new();
let mut offset: TextSize = 0.into();
let marker: fn(char) -> bool = if line.contains('^') { |c| c == '^' } else { |c| c == '|' };
while let Some(idx) = line.find(marker) {
offset += TextSize::try_from(idx).unwrap();
line = &line[idx..];
let mut len = line.chars().take_while(|&it| it == '^').count();
let mut continuation = false;
if len == 0 {
assert!(line.starts_with('|'));
continuation = true;
len = 1;
}
let range = TextRange::at(offset, len.try_into().unwrap());
let line_no_caret = &line[len..];
let end_marker = line_no_caret.find(|c| c == '$');
let next = line_no_caret.find(marker).map_or(line.len(), |it| it + len);
let cond = |end_marker| {
end_marker < next
&& (line_no_caret[end_marker + 1..].is_empty()
|| line_no_caret[end_marker + 1..]
.strip_prefix(|c: char| c.is_whitespace() || c == '^')
.is_some())
};
let mut content = match end_marker {
Some(end_marker) if cond(end_marker) => &line_no_caret[..end_marker],
_ => line_no_caret[..next - len].trim_end(),
};
let mut file = false;
if !continuation && content.starts_with("file") {
file = true;
content = &content["file".len()..];
}
let content = content.trim_start().to_string();
let annotation = if continuation {
LineAnnotation::Continuation { offset: range.end(), content }
} else {
LineAnnotation::Annotation { range, content, file }
};
res.push(annotation);
line = &line[next..];
offset += TextSize::try_from(next).unwrap();
}
res
}
#[test]
fn test_extract_annotations_1() {
let text = stdx::trim_indent(
r#"
fn main() {
let (x, y) = (9, 2);
//^ def ^ def
zoo + 1
} //^^^ type:
// | i32
// ^file
"#,
);
let res = extract_annotations(&text)
.into_iter()
.map(|(range, ann)| (&text[range], ann))
.collect::<Vec<_>>();
assert_eq!(
res[..3],
[("x", "def".into()), ("y", "def".into()), ("zoo", "type:\ni32\n".into())]
);
assert_eq!(res[3].0.len(), 115);
}
#[test]
fn test_extract_annotations_2() {
let text = stdx::trim_indent(
r#"
fn main() {
(x, y);
//^ a
// ^ b
//^^^^^^^^ c
}"#,
);
let res = extract_annotations(&text)
.into_iter()
.map(|(range, ann)| (&text[range], ann))
.collect::<Vec<_>>();
assert_eq!(res, [("x", "a".into()), ("y", "b".into()), ("(x, y)", "c".into())]);
}
/// Returns `false` if slow tests should not run, otherwise returns `true` and
/// also creates a file at `./target/.slow_tests_cookie` which serves as a flag
/// that slow tests did run.
pub fn skip_slow_tests() -> bool {
let should_skip = (std::env::var("CI").is_err() && std::env::var("RUN_SLOW_TESTS").is_err())
|| std::env::var("SKIP_SLOW_TESTS").is_ok();
if should_skip {
eprintln!("ignoring slow test");
} else {
let path = project_root().join("./target/.slow_tests_cookie");
fs::write(&path, ".").unwrap();
}
should_skip
}
/// Returns the path to the root directory of `rust-analyzer` project.
pub fn project_root() -> PathBuf {
let dir = env!("CARGO_MANIFEST_DIR");
PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
}
pub fn format_diff(chunks: Vec<dissimilar::Chunk<'_>>) -> String {
let mut buf = String::new();
for chunk in chunks {
let formatted = match chunk {
dissimilar::Chunk::Equal(text) => text.into(),
dissimilar::Chunk::Delete(text) => format!("\x1b[41m{}\x1b[0m", text),
dissimilar::Chunk::Insert(text) => format!("\x1b[42m{}\x1b[0m", text),
};
buf.push_str(&formatted);
}
buf
}
/// Utility for writing benchmark tests.
///
/// A benchmark test looks like this:
///
/// ```
/// #[test]
/// fn benchmark_foo() {
/// if skip_slow_tests() { return; }
///
/// let data = bench_fixture::some_fixture();
/// let analysis = some_setup();
///
/// let hash = {
/// let _b = bench("foo");
/// actual_work(analysis)
/// };
/// assert_eq!(hash, 92);
/// }
/// ```
///
/// * We skip benchmarks by default, to save time.
/// Ideal benchmark time is 800 -- 1500 ms in debug.
/// * We don't count preparation as part of the benchmark
/// * The benchmark itself returns some kind of numeric hash.
/// The hash is used as a sanity check that some code is actually run.
/// Otherwise, it's too easy to win the benchmark by just doing nothing.
pub fn bench(label: &'static str) -> impl Drop {
struct Bencher {
sw: StopWatch,
label: &'static str,
}
impl Drop for Bencher {
fn drop(&mut self) {
eprintln!("{}: {}", self.label, self.sw.elapsed());
}
}
Bencher { sw: StopWatch::start(), label }
}
/// Checks that the `file` has the specified `contents`. If that is not the
/// case, updates the file and then fails the test.
#[track_caller]
pub fn ensure_file_contents(file: &Path, contents: &str) {
if let Err(()) = try_ensure_file_contents(file, contents) {
panic!("Some files were not up-to-date");
}
}
/// Checks that the `file` has the specified `contents`. If that is not the
/// case, updates the file and return an Error.
pub fn try_ensure_file_contents(file: &Path, contents: &str) -> Result<(), ()> {
match std::fs::read_to_string(file) {
Ok(old_contents) if normalize_newlines(&old_contents) == normalize_newlines(contents) => {
return Ok(());
}
_ => (),
}
let display_path = file.strip_prefix(&project_root()).unwrap_or(file);
eprintln!(
"\n\x1b[31;1merror\x1b[0m: {} was not up-to-date, updating\n",
display_path.display()
);
if is_ci() {
eprintln!(" NOTE: run `cargo test` locally and commit the updated files\n");
}
if let Some(parent) = file.parent() {
let _ = std::fs::create_dir_all(parent);
}
std::fs::write(file, contents).unwrap();
Err(())
}
fn normalize_newlines(s: &str) -> String {
s.replace("\r\n", "\n")
}