rust/crates/test_utils/src/lib.rs
2020-06-23 17:04:10 +02:00

649 lines
20 KiB
Rust

//! Assorted testing utilities.
//!
//! Most notable things are:
//!
//! * Rich text comparison, which outputs a diff.
//! * Extracting markup (mainly, `<|>` markers) out of fixture strings.
//! * marks (see the eponymous module).
#[macro_use]
pub mod mark;
use std::{
env, fs,
path::{Path, PathBuf},
};
use serde_json::Value;
use stdx::split1;
use text_size::{TextRange, TextSize};
pub use ra_cfg::CfgOptions;
pub use rustc_hash::FxHashMap;
pub use difference::Changeset as __Changeset;
pub const CURSOR_MARKER: &str = "<|>";
/// 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() {
eprintln!("Left:\n{:?}\n\nRight:\n{:?}\n\nWhitespace difference\n", left, right);
} else {
let changeset = $crate::__Changeset::new(right, left, "\n");
eprintln!("Left:\n{}\n\nRight:\n{}\n\nDiff:\n{}\n", left, right, changeset);
}
eprintln!($($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 occurence of `<|>` 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 `<|>...<|>` 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 From<RangeOrOffset> for TextRange {
fn from(selection: RangeOrOffset) -> Self {
match selection {
RangeOrOffset::Range(it) => it,
RangeOrOffset::Offset(it) => TextRange::new(it, it),
}
}
}
/// Extracts `TextRange` or `TextSize` depending on the amount of `<|>` markers
/// found in `text`.
///
/// # Panics
/// Panics if no `<|>` 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_ranges(mut text: &str, tag: &str) -> (Vec<TextRange>, 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) {
text = &text[open.len()..];
let from = TextSize::of(&res);
stack.push(from);
} else if text.starts_with(&close) {
text = &text[close.len()..];
let from = stack.pop().unwrap_or_else(|| panic!("unmatched </{}>", tag));
let to = TextSize::of(&res);
ranges.push(TextRange::new(from, to));
}
}
}
}
assert!(stack.is_empty(), "unmatched <{}>", tag);
ranges.sort_by_key(|r| (r.start(), r.end()));
(ranges, res)
}
/// Inserts `<|>` 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("<|>");
res.push_str(&text[offset..]);
res
}
#[derive(Debug, Eq, PartialEq)]
pub struct FixtureEntry {
pub meta: FixtureMeta,
pub text: String,
}
#[derive(Debug, Eq, PartialEq)]
pub enum FixtureMeta {
Root { path: String },
File(FileMeta),
}
#[derive(Debug, Eq, PartialEq)]
pub struct FileMeta {
pub path: String,
pub crate_name: Option<String>,
pub deps: Vec<String>,
pub cfg: CfgOptions,
pub edition: Option<String>,
pub env: FxHashMap<String, String>,
}
impl FixtureMeta {
pub fn path(&self) -> &str {
match self {
FixtureMeta::Root { path } => &path,
FixtureMeta::File(f) => &f.path,
}
}
pub fn crate_name(&self) -> Option<&String> {
match self {
FixtureMeta::File(f) => f.crate_name.as_ref(),
_ => None,
}
}
pub fn cfg_options(&self) -> Option<&CfgOptions> {
match self {
FixtureMeta::File(f) => Some(&f.cfg),
_ => None,
}
}
pub fn edition(&self) -> Option<&String> {
match self {
FixtureMeta::File(f) => f.edition.as_ref(),
_ => None,
}
}
pub fn env(&self) -> impl Iterator<Item = (&String, &String)> {
struct EnvIter<'a> {
iter: Option<std::collections::hash_map::Iter<'a, String, String>>,
}
impl<'a> EnvIter<'a> {
fn new(meta: &'a FixtureMeta) -> Self {
Self {
iter: match meta {
FixtureMeta::File(f) => Some(f.env.iter()),
_ => None,
},
}
}
}
impl<'a> Iterator for EnvIter<'a> {
type Item = (&'a String, &'a String);
fn next(&mut self) -> Option<Self::Item> {
self.iter.as_mut().and_then(|i| i.next())
}
}
EnvIter::new(self)
}
}
/// Parses text which looks like this:
///
/// ```not_rust
/// //- some meta
/// line 1
/// line 2
/// // - other meta
/// ```
pub fn parse_fixture(ra_fixture: &str) -> Vec<FixtureEntry> {
let fixture = indent_first_line(ra_fixture);
let margin = fixture_margin(&fixture);
let mut lines = fixture
.split('\n') // don't use `.lines` to not drop `\r\n`
.enumerate()
.filter_map(|(ix, line)| {
if line.len() >= margin {
assert!(line[..margin].trim().is_empty());
let line_content = &line[margin..];
if !line_content.starts_with("//-") {
assert!(
!line_content.contains("//-"),
r#"Metadata line {} has invalid indentation. All metadata lines need to have the same indentation.
The offending line: {:?}"#,
ix,
line
);
}
Some(line_content)
} else {
assert!(line.trim().is_empty());
None
}
});
let mut res: Vec<FixtureEntry> = Vec::new();
for line in lines.by_ref() {
if line.starts_with("//-") {
let meta = line["//-".len()..].trim().to_string();
let meta = parse_meta(&meta);
res.push(FixtureEntry { meta, text: String::new() })
} else if let Some(entry) = res.last_mut() {
entry.text.push_str(line);
entry.text.push('\n');
}
}
res
}
//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
fn parse_meta(meta: &str) -> FixtureMeta {
let components = meta.split_ascii_whitespace().collect::<Vec<_>>();
if components[0] == "root" {
let path = components[1].to_string();
assert!(path.starts_with("/") && path.ends_with("/"));
return FixtureMeta::Root { path };
}
let path = components[0].to_string();
assert!(path.starts_with("/"));
let mut krate = None;
let mut deps = Vec::new();
let mut edition = None;
let mut cfg = CfgOptions::default();
let mut env = FxHashMap::default();
for component in components[1..].iter() {
let (key, value) = split1(component, ':').unwrap();
match key {
"crate" => krate = Some(value.to_string()),
"deps" => deps = value.split(',').map(|it| it.to_string()).collect(),
"edition" => edition = Some(value.to_string()),
"cfg" => {
for key in value.split(',') {
match split1(key, '=') {
None => cfg.insert_atom(key.into()),
Some((k, v)) => cfg.insert_key_value(k.into(), v.into()),
}
}
}
"env" => {
for key in value.split(',') {
if let Some((k, v)) = split1(key, '=') {
env.insert(k.into(), v.into());
}
}
}
_ => panic!("bad component: {:?}", component),
}
}
FixtureMeta::File(FileMeta { path, crate_name: krate, deps, edition, cfg, env })
}
/// Adjusts the indentation of the first line to the minimum indentation of the rest of the lines.
/// This allows fixtures to start off in a different indentation, e.g. to align the first line with
/// the other lines visually:
/// ```
/// let fixture = "//- /lib.rs
/// mod foo;
/// //- /foo.rs
/// fn bar() {}
/// ";
/// assert_eq!(fixture_margin(fixture),
/// " //- /lib.rs
/// mod foo;
/// //- /foo.rs
/// fn bar() {}
/// ")
/// ```
fn indent_first_line(fixture: &str) -> String {
if fixture.is_empty() {
return String::new();
}
let mut lines = fixture.lines();
let first_line = lines.next().unwrap();
if first_line.contains("//-") {
let rest = lines.collect::<Vec<_>>().join("\n");
let fixed_margin = fixture_margin(&rest);
let fixed_indent = fixed_margin - indent_len(first_line);
format!("\n{}{}\n{}", " ".repeat(fixed_indent), first_line, rest)
} else {
fixture.to_owned()
}
}
fn fixture_margin(fixture: &str) -> usize {
fixture
.lines()
.filter(|it| it.trim_start().starts_with("//-"))
.map(indent_len)
.next()
.expect("empty fixture")
}
fn indent_len(s: &str) -> usize {
s.len() - s.trim_start().len()
}
#[test]
#[should_panic]
fn parse_fixture_checks_further_indented_metadata() {
parse_fixture(
r"
//- /lib.rs
mod bar;
fn foo() {}
//- /bar.rs
pub fn baz() {}
",
);
}
#[test]
fn parse_fixture_can_handle_dedented_first_line() {
let fixture = "//- /lib.rs
mod foo;
//- /foo.rs
struct Bar;
";
assert_eq!(
parse_fixture(fixture),
parse_fixture(
"//- /lib.rs
mod foo;
//- /foo.rs
struct Bar;
"
)
)
}
#[test]
fn parse_fixture_gets_full_meta() {
let parsed = parse_fixture(
r"
//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b,atom env:OUTDIR=path/to,OTHER=foo
mod m;
",
);
assert_eq!(1, parsed.len());
let parsed = &parsed[0];
assert_eq!("mod m;\n\n", parsed.text);
let meta = &parsed.meta;
assert_eq!("foo", meta.crate_name().unwrap());
assert_eq!("/lib.rs", meta.path());
assert!(meta.cfg_options().is_some());
assert_eq!(2, meta.env().count());
}
/// Same as `parse_fixture`, except it allow empty fixture
pub fn parse_single_fixture(ra_fixture: &str) -> Option<FixtureEntry> {
if !ra_fixture.lines().any(|it| it.trim_start().starts_with("//-")) {
return None;
}
let fixtures = parse_fixture(ra_fixture);
if fixtures.len() > 1 {
panic!("too many fixtures");
}
fixtures.into_iter().nth(0)
}
// Comparison functionality borrowed from cargo:
/// Compare a line with an expected pattern.
/// - Use `[..]` as a wildcard to match 0 or more characters on the same line
/// (similar to `.*` in a regex).
pub fn lines_match(expected: &str, actual: &str) -> bool {
// Let's not deal with / vs \ (windows...)
// First replace backslash-escaped backslashes with forward slashes
// which can occur in, for example, JSON output
let expected = expected.replace(r"\\", "/").replace(r"\", "/");
let mut actual: &str = &actual.replace(r"\\", "/").replace(r"\", "/");
for (i, part) in expected.split("[..]").enumerate() {
match actual.find(part) {
Some(j) => {
if i == 0 && j != 0 {
return false;
}
actual = &actual[j + part.len()..];
}
None => return false,
}
}
actual.is_empty() || expected.ends_with("[..]")
}
#[test]
fn lines_match_works() {
assert!(lines_match("a b", "a b"));
assert!(lines_match("a[..]b", "a b"));
assert!(lines_match("a[..]", "a b"));
assert!(lines_match("[..]", "a b"));
assert!(lines_match("[..]b", "a b"));
assert!(!lines_match("[..]b", "c"));
assert!(!lines_match("b", "c"));
assert!(!lines_match("b", "cb"));
}
/// Compares JSON object for approximate equality.
/// You can use `[..]` wildcard in strings (useful for OS dependent things such
/// as paths). You can use a `"{...}"` string literal as a wildcard for
/// arbitrary nested JSON. Arrays are sorted before comparison.
pub fn find_mismatch<'a>(expected: &'a Value, actual: &'a Value) -> Option<(&'a Value, &'a Value)> {
use serde_json::Value::*;
match (expected, actual) {
(&Number(ref l), &Number(ref r)) if l == r => None,
(&Bool(l), &Bool(r)) if l == r => None,
(&String(ref l), &String(ref r)) if lines_match(l, r) => None,
(&Array(ref l), &Array(ref r)) => {
if l.len() != r.len() {
return Some((expected, actual));
}
let mut l = l.iter().collect::<Vec<_>>();
let mut r = r.iter().collect::<Vec<_>>();
l.retain(|l| match r.iter().position(|r| find_mismatch(l, r).is_none()) {
Some(i) => {
r.remove(i);
false
}
None => true,
});
if !l.is_empty() {
assert!(!r.is_empty());
Some((&l[0], &r[0]))
} else {
assert_eq!(r.len(), 0);
None
}
}
(&Object(ref l), &Object(ref r)) => {
let same_keys = l.len() == r.len() && l.keys().all(|k| r.contains_key(k));
if !same_keys {
return Some((expected, actual));
}
l.values().zip(r.values()).filter_map(|(l, r)| find_mismatch(l, r)).next()
}
(&Null, &Null) => None,
// magic string literal "{...}" acts as wildcard for any sub-JSON
(&String(ref l), _) if l == "{...}" => None,
_ => Some((expected, actual)),
}
}
/// Calls callback `f` with input code and file paths for each `.rs` file in `test_data_dir`
/// subdirectories defined by `paths`.
///
/// If the content of the matching output file differs from the output of `f()`
/// the test will fail.
///
/// If there is no matching output file it will be created and filled with the
/// output of `f()`, but the test will fail.
pub fn dir_tests<F>(test_data_dir: &Path, paths: &[&str], outfile_extension: &str, f: F)
where
F: Fn(&str, &Path) -> String,
{
for (path, input_code) in collect_rust_files(test_data_dir, paths) {
let actual = f(&input_code, &path);
let path = path.with_extension(outfile_extension);
if !path.exists() {
println!("\nfile: {}", path.display());
println!("No .txt file with expected result, creating...\n");
println!("{}\n{}", input_code, actual);
fs::write(&path, &actual).unwrap();
panic!("No expected result");
}
let expected = read_text(&path);
assert_equal_text(&expected, &actual, &path);
}
}
/// Collects all `.rs` files from `dir` subdirectories defined by `paths`.
pub fn collect_rust_files(root_dir: &Path, paths: &[&str]) -> Vec<(PathBuf, String)> {
paths
.iter()
.flat_map(|path| {
let path = root_dir.to_owned().join(path);
rust_files_in_dir(&path).into_iter()
})
.map(|path| {
let text = read_text(&path);
(path, text)
})
.collect()
}
/// Collects paths to all `.rs` files from `dir` in a sorted `Vec<PathBuf>`.
fn rust_files_in_dir(dir: &Path) -> Vec<PathBuf> {
let mut acc = Vec::new();
for file in fs::read_dir(&dir).unwrap() {
let file = file.unwrap();
let path = file.path();
if path.extension().unwrap_or_default() == "rs" {
acc.push(path);
}
}
acc.sort();
acc
}
/// Returns the path to the root directory of `rust-analyzer` project.
pub fn project_dir() -> PathBuf {
let dir = env!("CARGO_MANIFEST_DIR");
PathBuf::from(dir).parent().unwrap().parent().unwrap().to_owned()
}
/// Read file and normalize newlines.
///
/// `rustc` seems to always normalize `\r\n` newlines to `\n`:
///
/// ```
/// let s = "
/// ";
/// assert_eq!(s.as_bytes(), &[10]);
/// ```
///
/// so this should always be correct.
pub fn read_text(path: &Path) -> String {
fs::read_to_string(path)
.unwrap_or_else(|_| panic!("File at {:?} should be valid", path))
.replace("\r\n", "\n")
}
/// 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();
if should_skip {
eprintln!("ignoring slow test")
} else {
let path = project_dir().join("./target/.slow_tests_cookie");
fs::write(&path, ".").unwrap();
}
should_skip
}
/// Asserts that `expected` and `actual` strings are equal. If they differ only
/// in trailing or leading whitespace the test won't fail and
/// the contents of `actual` will be written to the file located at `path`.
fn assert_equal_text(expected: &str, actual: &str, path: &Path) {
if expected == actual {
return;
}
let dir = project_dir();
let pretty_path = path.strip_prefix(&dir).unwrap_or_else(|_| path);
if expected.trim() == actual.trim() {
println!("whitespace difference, rewriting");
println!("file: {}\n", pretty_path.display());
fs::write(path, actual).unwrap();
return;
}
if env::var("UPDATE_EXPECTATIONS").is_ok() {
println!("rewriting {}", pretty_path.display());
fs::write(path, actual).unwrap();
return;
}
assert_eq_text!(expected, actual, "file: {}", pretty_path.display());
}