claude@clouddev1
41b7e9a049
One-time, mechanical reformat — no functional changes. The tree was not rustfmt-clean (~1800 hunks across ~100 files); this brings it to stock `cargo fmt` defaults so a `cargo fmt --check` CI gate can follow. Behaviour-preserving: 2509 pass / 0 fail / 1 ignored (unchanged baseline), clippy clean. A .git-blame-ignore-revs entry follows so `git blame` skips this commit.
119 lines
3.6 KiB
Rust
119 lines
3.6 KiB
Rust
//! Shortid generation and validation.
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//!
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//! Per ADR-0005, the `shortid` user-facing type is a base58
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//! random identifier of 10–12 characters with no ambiguous
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//! glyphs (no `0`/`O`/`I`/`l`). The generator is small enough
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//! to live in the DSL crate alongside the type definition.
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use rand::RngExt;
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/// Base58 alphabet — Bitcoin-style. 0 / O / I / l are excluded
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/// because they are easily confused in print.
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const ALPHABET: &[u8; 58] = b"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
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const DEFAULT_LEN: usize = 10;
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/// Length bounds accepted on user-supplied shortid values.
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pub const MIN_LEN: usize = 10;
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pub const MAX_LEN: usize = 12;
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/// Generate a fresh shortid using the thread-local RNG.
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#[must_use]
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pub fn generate() -> String {
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generate_with_rng(&mut rand::rng())
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}
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/// Generate a shortid from a caller-supplied RNG.
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///
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/// Lets `seed --seed <n>` produce **reproducible** shortid values
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/// (ADR-0048 D4) by threading its seeded RNG through, while the default
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/// [`generate`] keeps its thread-RNG behaviour for ordinary inserts.
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#[must_use]
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pub fn generate_with_rng<R: RngExt + ?Sized>(rng: &mut R) -> String {
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let mut out = String::with_capacity(DEFAULT_LEN);
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for _ in 0..DEFAULT_LEN {
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let idx = rng.random_range(0..ALPHABET.len());
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out.push(ALPHABET[idx] as char);
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}
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out
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}
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/// Validate a user-supplied shortid value.
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pub fn validate(value: &str) -> Result<(), String> {
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if value.len() < MIN_LEN || value.len() > MAX_LEN {
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return Err(format!(
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"shortid must be {MIN_LEN}–{MAX_LEN} characters; got {} character(s)",
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value.chars().count()
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));
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}
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for c in value.chars() {
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if !ALPHABET.contains(&(c as u8)) {
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return Err(format!(
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"shortid contains '{c}', which is not in the base58 alphabet \
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(no 0, O, I, or l; ASCII letters and digits otherwise)"
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));
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}
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}
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Ok(())
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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use pretty_assertions::assert_eq;
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#[test]
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fn generated_ids_have_default_length() {
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let id = generate();
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assert_eq!(id.len(), DEFAULT_LEN);
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}
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#[test]
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fn generated_ids_use_only_base58_alphabet() {
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for _ in 0..100 {
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let id = generate();
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for c in id.chars() {
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assert!(
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ALPHABET.contains(&(c as u8)),
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"char {c:?} not in base58 alphabet"
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);
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}
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}
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}
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#[test]
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fn generated_ids_are_not_all_identical() {
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// Probabilistically extremely unlikely with a good RNG;
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// catches a wholly broken generator (constant output).
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let a = generate();
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let b = generate();
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let c = generate();
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assert!(
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a != b || b != c,
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"all three generated ids were identical: {a}, {b}, {c}"
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);
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}
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#[test]
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fn validate_accepts_well_formed_values() {
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assert!(validate("23456789Ab").is_ok()); // 10 chars
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assert!(validate("23456789AbCD").is_ok()); // 12 chars
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}
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#[test]
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fn validate_rejects_too_short_or_too_long() {
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let err = validate("short").unwrap_err();
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assert!(err.contains("characters"));
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let err = validate("waytoolongafornow").unwrap_err();
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assert!(err.contains("characters"));
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}
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#[test]
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fn validate_rejects_ambiguous_glyphs() {
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for bad in ["0aaaaaaaaa", "Oaaaaaaaaa", "Iaaaaaaaaa", "laaaaaaaaa"] {
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let err = validate(bad).unwrap_err();
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assert!(err.contains("base58"), "for {bad}: {err}");
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}
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}
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}
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