Function effective_test_framework 

pub fn effective_test_framework(
    target: &str,
    cfg: &TargetScaffoldConfig,
) -> String

The effective test framework for target given its validated config, applying the §20.6.2 target-appropriate default for any unset choice.

This is the single source of truth the build driver uses to pick which idiom crate::CodeGenerator::generate_tests emits, so the transpiled test files match the scaffolded manifest (e.g. a package.json with the Jest dev-dependency gets Jest-shaped test files). Returns:

• js/ts: "vitest" (default) or "jest",
• python: "pytest" (default) or "unittest",
• rust: "cargo" (universal), go: "go" (universal).