harn-cli 0.10.145

CLI for the Harn programming language — run, test, REPL, format, and lint
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//! The environment a conformance case's subprocesses run under.
//!
//! A conformance case is a `.harn` script, and many of them shell out: they
//! resolve a repository root with `git`, re-exec `harn` against a generated
//! child script, or probe a toolchain. Those children need the runner's own
//! environment to find anything at all, so a case inherits.
//!
//! Since harn#8477 an inheriting spawn has to have a session environment
//! behind it. The process host cannot tell a deliberate inherit apart from a
//! forgotten one, and while it treated the forgotten case as permission, a
//! credential could reach a child nobody meant to hand it to. `harn run`
//! already launched a policy for the same reason; this is the conformance
//! runner's equivalent, and `inherited` reproduces its behaviour exactly.

/// Declare the runner's default environment for the life of one case.
///
/// Only when nothing else has declared one, and the previous declaration is
/// restored on drop: a case must not silently widen or erase a policy an
/// enclosing surface chose.
pub(super) fn declare() -> harn_vm::stdlib::process::SessionEnvironmentGuard {
    harn_vm::stdlib::process::declare_session_environment_if_absent(
        harn_vm::security::SessionEnvironment::inherited(),
    )
}