Function concrete_pin_version 

pub fn concrete_pin_version(
    requirement: &str,
    ecosystem: EcosystemId,
) -> Option<&str>

Returns the concrete version text requirement denotes, or None if requirement is not the shape of a single concrete version.

Any pin marker (=/==, or a single-value bracket wrap like NuGet’s [1.0.0]) is stripped off. The only shape safe to query OSV with directly, and, for #233, the only shape safe to compare against a real registry version string in the yanked-version probe. A wrong answer here is invisible in testing (OSV silently returns {} for a fabricated version; the yanked probe silently finds no match), so getting this right matters more than covering every ecosystem’s full range grammar.

An explicit pin marker is always accepted, and its marker is stripped from the returned text — required because PyPI’s parser retains the pep440 comparator in Dependency::version_requirement() (an exact pin parses to "==4.9.0", not "4.9.0"; confirmed by deps-pypi’s test_basic_pinned), so comparing the unstripped text against a real registry version string ("4.9.0") would never match. A bare requirement (no marker) is returned verbatim, and is accepted only for ecosystems where a bare version is not itself a range by default (critique C2) — see bare_version_is_a_range.

Examples

use deps_core::EcosystemId;
use deps_core::lsp_helpers::concrete_pin_version;

// An explicit pin marker is stripped, for any ecosystem.
assert_eq!(
    concrete_pin_version("=1.2.3", EcosystemId::Cargo),
    Some("1.2.3")
);

// Cargo's bare version is a caret range by default, not a pin.
assert_eq!(concrete_pin_version("1.2.3", EcosystemId::Cargo), None);

// Maven has no implicit range operator, so a bare version is exact.
assert_eq!(
    concrete_pin_version("2.14.1", EcosystemId::Maven),
    Some("2.14.1")
);