rust/crates/test_utils/src/lib.rs
2018-12-21 18:13:21 +03:00

265 lines
8.3 KiB
Rust

use std::fmt;
use itertools::Itertools;
use text_unit::{TextRange, TextUnit};
use serde_json::Value;
pub use difference::Changeset as __Changeset;
pub const CURSOR_MARKER: &str = "<|>";
#[macro_export]
macro_rules! assert_eq_text {
($expected:expr, $actual:expr) => {
assert_eq_text!($expected, $actual,)
};
($expected:expr, $actual:expr, $($tt:tt)*) => {{
let expected = $expected;
let actual = $actual;
if expected != actual {
if expected.trim() == actual.trim() {
eprintln!("Expected:\n{:?}\n\nActual:\n{:?}\n\nWhitespace difference\n", expected, actual);
} else {
let changeset = $crate::__Changeset::new(actual, expected, "\n");
eprintln!("Expected:\n{}\n\nActual:\n{}\n\nDiff:\n{}\n", expected, actual, changeset);
}
eprintln!($($tt)*);
panic!("text differs");
}
}};
}
pub fn assert_eq_dbg(expected: &str, actual: &impl fmt::Debug) {
let actual = format!("{:?}", actual);
let expected = expected.lines().map(|l| l.trim()).join(" ");
assert_eq!(expected, actual);
}
pub fn extract_offset(text: &str) -> (TextUnit, String) {
match try_extract_offset(text) {
None => panic!("text should contain cursor marker"),
Some(result) => result,
}
}
pub fn try_extract_offset(text: &str) -> Option<(TextUnit, 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 = TextUnit::from(cursor_pos as u32);
Some((cursor_pos, new_text))
}
pub fn extract_range(text: &str) -> (TextRange, String) {
match try_extract_range(text) {
None => panic!("text should contain cursor marker"),
Some(result) => result,
}
}
pub 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::from_to(start, end), text))
}
/// Extracts ranges, marked with `<tag> </tag>` paris 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 = TextUnit::of_str(&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 = TextUnit::of_str(&res);
ranges.push(TextRange::from_to(from, to));
}
}
}
}
assert!(stack.is_empty(), "unmatched <{}>", tag);
ranges.sort_by_key(|r| (r.start(), r.end()));
(ranges, res)
}
pub fn add_cursor(text: &str, offset: TextUnit) -> String {
let offset: u32 = offset.into();
let offset: usize = offset as usize;
let mut res = String::new();
res.push_str(&text[..offset]);
res.push_str("<|>");
res.push_str(&text[offset..]);
res
}
#[derive(Debug)]
pub struct FixtureEntry {
pub meta: String,
pub text: String,
}
/// Parses text wich looks like this:
///
/// ```notrust
/// //- some meta
/// line 1
/// line 2
/// // - other meta
/// ```
pub fn parse_fixture(fixture: &str) -> Vec<FixtureEntry> {
let mut res = Vec::new();
let mut buf = String::new();
let mut meta: Option<&str> = None;
macro_rules! flush {
() => {
if let Some(meta) = meta {
res.push(FixtureEntry {
meta: meta.to_string(),
text: buf.clone(),
});
buf.clear();
}
};
};
let margin = fixture
.lines()
.filter(|it| it.trim_start().starts_with("//-"))
.map(|it| it.len() - it.trim_start().len())
.next()
.expect("empty fixture");
let lines = fixture.lines().filter_map(|line| {
if line.len() >= margin {
assert!(line[..margin].trim().is_empty());
Some(&line[margin..])
} else {
assert!(line.trim().is_empty());
None
}
});
for line in lines {
if line.starts_with("//-") {
flush!();
buf.clear();
meta = Some(line["//-".len()..].trim());
continue;
}
buf.push_str(line);
buf.push('\n');
}
flush!();
res
}
// 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("\\\\", "/").replace("\\", "/");
let mut actual: &str = &actual.replace("\\\\", "/").replace("\\", "/");
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 (useful for parts of object emitted by other programs
// (e.g. rustc) rather than Cargo itself). 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))
.nth(0)
}
(&Null, &Null) => None,
// magic string literal "{...}" acts as wildcard for any sub-JSON
(&String(ref l), _) if l == "{...}" => None,
_ => Some((expected, actual)),
}
}