Struct ConfigLock 

pub struct ConfigLock { /* private fields */ }

A guard that holds the global configuration lock and provides override functionality.

This struct acts as both a lock guard (preventing other tests from modifying global config) and as the only way to create configuration overrides. Override guards cannot outlive this ConfigLock, ensuring proper synchronization.

Implementations

impl ConfigLock

pub fn override_key<'a, T: AttrValue>( &'a self, key: Key<T>, value: T, ) -> ConfigValueGuard<'a, T>

Create a configuration override that is active until the returned guard is dropped.

Each call pushes a new frame onto a per-key override stack within the Source::TestOverride layer. The topmost frame defines the effective value seen by get() and in the mirrored environment variable (if any). When a guard is dropped, its frame is removed: if it was the top, the previous frame (if any) becomes active or the key and env var are restored to their prior state.

The returned guard must not outlive this ConfigLock.

Trait Implementations

impl Drop for ConfigLock

When a ConfigLock is dropped, the special Source::TestOverride layer (if present) is removed entirely. This discards all temporary overrides created under the lock, ensuring they cannot leak into subsequent tests or callers. Other layers (Runtime, Env, File, ClientOverride, and defaults) are left untouched.

Note: individual values within the TestOverride layer may already have been restored by ConfigValueGuards as they drop. This final removal guarantees no residual layer remains once the lock itself is released.

fn drop(&mut self)

Executes the destructor for this type.