dynfmt2 0.4.0

A crate for formatting strings dynamically. Forked from dynfmt.
Documentation 
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#![cfg(feature = "python")]

use std::collections::BTreeMap;

use dynfmt2::{Format, PythonFormat};

macro_rules! test_fmt {
    ($name:ident, $expected:expr, $format:expr, $($args:expr),* $(,)*) => {
        #[test]
        fn $name() {
            assert_eq!(
                $expected,
                PythonFormat
                    .format($format, &[$($args),*])
                    .expect("formatting failed")
            );
        }
    };
}

test_fmt!(string_display, "hello, world!", "hello, %s!", "world");
test_fmt!(number_display, "hello, 42!", "hello, %s!", 42);
test_fmt!(negative_display, "hello, -42!", "hello, %s!", -42);
test_fmt!(float_display, "hello, 4.2!", "hello, %s!", 4.2);
test_fmt!(boolean_display, "hello, true!", "hello, %s!", true);
test_fmt!(array_display, "hello, [1,2,3]!", "hello, %s!", [1, 2, 3]);
test_fmt!(object_display, "hello, {\"foo\":\"bar\"}!", "hello, %s!", {
    let mut map = BTreeMap::new();
    map.insert("foo", "bar");
    map
});

test_fmt!(string_repr, "hello, \"world\"!", "hello, %r!", "world");
test_fmt!(array_repr, "hello, [1,2,3]!", "hello, %r!", [1, 2, 3]);
test_fmt!(
    array_repr_alt,
    "hello, [\n  1,\n  2,\n  3\n]!",
    "hello, %#r!",
    [1, 2, 3],
);
test_fmt!(object_repr, "hello, {\"foo\":\"bar\"}!", "hello, %r!", {
    let mut map = BTreeMap::new();
    map.insert("foo", "bar");
    map
});

test_fmt!(number_octal, "hello, 52!", "hello, %o!", 42);
test_fmt!(number_octal_alt, "hello, 0o52!", "hello, %#o!", 42);
test_fmt!(number_lower_hex, "hello, 2a!", "hello, %x!", 42);
test_fmt!(number_lower_hex_alt, "hello, 0x2a!", "hello, %#x!", 42);
test_fmt!(number_upper_hex, "hello, 2A!", "hello, %X!", 42);
test_fmt!(number_upper_hex_alt, "hello, 0x2A!", "hello, %#X!", 42);

test_fmt!(float_lower_exp, "hello, 4.2e0!", "hello, %e!", 4.2);
test_fmt!(float_upper_exp, "hello, 4.2E0!", "hello, %E!", 4.2);

// Width formatting tests
test_fmt!(width_right_aligned, "hello,    42!", "hello, %5s!", 42);
test_fmt!(width_left_aligned, "hello, 42   !", "hello, %-5s!", 42);
test_fmt!(width_with_zero_padding, "hello, 00042!", "hello, %05s!", 42);
test_fmt!(
    width_larger_than_content,
    "hello,   abc!",
    "hello, %5s!",
    "abc"
);
test_fmt!(
    width_smaller_than_content,
    "hello, abcdef!",
    "hello, %3s!",
    "abcdef"
);
test_fmt!(width_from_argument, "hello,   42!", "hello, %*s!", 4, 42);

// Precision formatting tests
test_fmt!(precision_float, "1.23", "%.2f", 1.23456);
test_fmt!(precision_float_padded, "[    1.23]", "[%8.2f]", 1.23456);
test_fmt!(precision_zero_padded, "00001.23", "%08.2f", 1.23456);
test_fmt!(precision_from_argument, "1.23", "%.*f", 2.0, 1.23456);
test_fmt!(precision_string_truncates, "hel", "%.3s", "hello");
// `%s` precision truncates the converted output regardless of the argument type.
test_fmt!(precision_string_truncates_int, "123", "%.3s", 12345);
// `%r` precision truncates the (JSON) representation, like Python's repr truncation.
test_fmt!(precision_repr_truncates, "[1,", "%.3r", [1, 2, 3]);

// Width is measured in characters, not bytes (multi-byte UTF-8)
test_fmt!(width_unicode_chars, "[ café]", "[%5s]", "café");

#[test]
fn test_width_formatting_demo() {
    // Test that width formatting is working correctly
    let result = PythonFormat.format("Width: %5s, Left: %-5s, Zero: %05s", ["abc", "def", "42"]);
    assert_eq!(result.unwrap(), "Width:   abc, Left: def  , Zero: 00042");
}

#[test]
fn test_width_formatting_issue_3() {
    // reported test case for https://github.com/dathere/dynfmt2/issues/3
    let result = PythonFormat.format("[%5s]", ["A"]);
    assert_eq!(result.unwrap(), "[    A]");
}

#[test]
fn string_display_by_name() {
    let mut args = std::collections::BTreeMap::new();
    args.insert("name", "world");

    assert_eq!(
        "hello, world!",
        PythonFormat
            .format("hello, %(name)s!", args)
            .expect("formatting failed")
    );
}