writeable/
testing.rs

1// This file is part of ICU4X. For terms of use, please see the file
2// called LICENSE at the top level of the ICU4X source tree
3// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
4
5use crate::*;
6use alloc::string::String;
7use alloc::vec::Vec;
8
9pub(crate) struct TestWriter {
10    pub(crate) string: String,
11    pub(crate) parts: Vec<(usize, usize, Part)>,
12}
13
14impl TestWriter {
15    pub(crate) fn finish(mut self) -> (String, Vec<(usize, usize, Part)>) {
16        // Sort by first open and last closed
17        self.parts
18            .sort_unstable_by_key(|(begin, end, _)| (*begin, end.wrapping_neg()));
19        (self.string, self.parts)
20    }
21}
22
23impl fmt::Write for TestWriter {
24    fn write_str(&mut self, s: &str) -> fmt::Result {
25        self.string.write_str(s)
26    }
27    fn write_char(&mut self, c: char) -> fmt::Result {
28        self.string.write_char(c)
29    }
30}
31
32impl PartsWrite for TestWriter {
33    type SubPartsWrite = Self;
34    fn with_part(
35        &mut self,
36        part: Part,
37        mut f: impl FnMut(&mut Self::SubPartsWrite) -> fmt::Result,
38    ) -> fmt::Result {
39        let start = self.string.len();
40        f(self)?;
41        let end = self.string.len();
42        if start < end {
43            self.parts.push((start, end, part));
44        }
45        Ok(())
46    }
47}
48
49#[doc(hidden)]
50pub fn writeable_to_parts_for_test<W: Writeable>(
51    writeable: &W,
52) -> (String, Vec<(usize, usize, Part)>) {
53    let mut writer = TestWriter {
54        string: alloc::string::String::new(),
55        parts: Vec::new(),
56    };
57    #[expect(clippy::expect_used)] // for test code
58    writeable
59        .write_to_parts(&mut writer)
60        .expect("String writer infallible");
61    writer.finish()
62}
63
64#[expect(clippy::type_complexity)]
65#[doc(hidden)]
66pub fn try_writeable_to_parts_for_test<W: TryWriteable>(
67    writeable: &W,
68) -> (String, Vec<(usize, usize, Part)>, Option<W::Error>) {
69    let mut writer = TestWriter {
70        string: alloc::string::String::new(),
71        parts: Vec::new(),
72    };
73    #[expect(clippy::expect_used)] // for test code
74    let result = writeable
75        .try_write_to_parts(&mut writer)
76        .expect("String writer infallible");
77    let (actual_str, actual_parts) = writer.finish();
78    (actual_str, actual_parts, result.err())
79}
writeable/testing.rs

writeable/
testing.rs
