Function score 

pub fn score(
    features: &JitFeatures,
    purpose: JitPurpose,
) -> (f64, JitContributions)

Available on crate feature vcs-git only.

Compute the composite JIT risk score and its per-group breakdown.

The term weights and signs come from the JIT literature (see the module docs): size, diffusion, and history are positively signed; experience is negative (experienced authors induce fewer defects); purpose adds for fixes and subtracts for reverts. The contributions sum to the score before the final non-negative floor.

The f64 casts of count fields are exact for every realistic input (counts never approach 2^53) and the score is ordinal, so the precision lint is allowed locally.