Vendor things

third-party/vendor/tracing-subscriber/tests/option.rs

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+#![cfg(feature = "registry")]
+use tracing_core::{subscriber::Interest, LevelFilter, Metadata, Subscriber};
+use tracing_subscriber::{layer, prelude::*};
+
+// A basic layer that returns its inner for `max_level_hint`
+#[derive(Debug)]
+struct BasicLayer(Option<LevelFilter>);
+impl<S: Subscriber> tracing_subscriber::Layer<S> for BasicLayer {
+    fn register_callsite(&self, _m: &Metadata<'_>) -> Interest {
+        Interest::sometimes()
+    }
+
+    fn enabled(&self, _m: &Metadata<'_>, _: layer::Context<'_, S>) -> bool {
+        true
+    }
+
+    fn max_level_hint(&self) -> Option<LevelFilter> {
+        self.0
+    }
+}
+
+// This test is just used to compare to the tests below
+#[test]
+fn just_layer() {
+    let subscriber = tracing_subscriber::registry().with(LevelFilter::INFO);
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::INFO));
+}
+
+#[test]
+fn subscriber_and_option_some_layer() {
+    let subscriber = tracing_subscriber::registry()
+        .with(LevelFilter::INFO)
+        .with(Some(LevelFilter::DEBUG));
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::DEBUG));
+}
+
+#[test]
+fn subscriber_and_option_none_layer() {
+    // None means the other layer takes control
+    let subscriber = tracing_subscriber::registry()
+        .with(LevelFilter::ERROR)
+        .with(None::<LevelFilter>);
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::ERROR));
+}
+
+#[test]
+fn just_option_some_layer() {
+    // Just a None means everything is off
+    let subscriber = tracing_subscriber::registry().with(None::<LevelFilter>);
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::OFF));
+}
+
+/// Tests that the logic tested in `doesnt_override_none` works through the reload subscriber
+#[test]
+fn just_option_none_layer() {
+    let subscriber = tracing_subscriber::registry().with(Some(LevelFilter::ERROR));
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::ERROR));
+}
+
+// Test that the `None` max level hint only applies if its the only layer
+#[test]
+fn none_outside_doesnt_override_max_level() {
+    // None means the other layer takes control
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(None))
+        .with(None::<LevelFilter>);
+    assert_eq!(
+        subscriber.max_level_hint(),
+        None,
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The `None`-returning layer still wins
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(None))
+        .with(Some(LevelFilter::ERROR));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::ERROR),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Check that we aren't doing anything truly wrong
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(Some(LevelFilter::DEBUG)))
+        .with(None::<LevelFilter>);
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Test that per-subscriber filters aren't affected
+
+    // One layer is None so it "wins"
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(None))
+        .with(None::<LevelFilter>.with_filter(LevelFilter::DEBUG));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        None,
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The max-levels wins
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(Some(LevelFilter::INFO)))
+        .with(None::<LevelFilter>.with_filter(LevelFilter::DEBUG));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Test filter on the other layer
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(Some(LevelFilter::INFO)).with_filter(LevelFilter::DEBUG))
+        .with(None::<LevelFilter>);
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(None).with_filter(LevelFilter::DEBUG))
+        .with(None::<LevelFilter>);
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The `OFF` from `None` over overridden.
+    let subscriber = tracing_subscriber::registry()
+        .with(BasicLayer(Some(LevelFilter::INFO)))
+        .with(None::<LevelFilter>);
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::INFO),
+        "\n stack: {:#?}",
+        subscriber
+    );
+}
+
+// Test that the `None` max level hint only applies if its the only layer
+#[test]
+fn none_inside_doesnt_override_max_level() {
+    // None means the other layer takes control
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>)
+        .with(BasicLayer(None));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        None,
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The `None`-returning layer still wins
+    let subscriber = tracing_subscriber::registry()
+        .with(Some(LevelFilter::ERROR))
+        .with(BasicLayer(None));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::ERROR),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Check that we aren't doing anything truly wrong
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>)
+        .with(BasicLayer(Some(LevelFilter::DEBUG)));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Test that per-subscriber filters aren't affected
+
+    // One layer is None so it "wins"
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>.with_filter(LevelFilter::DEBUG))
+        .with(BasicLayer(None));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        None,
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The max-levels wins
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>.with_filter(LevelFilter::DEBUG))
+        .with(BasicLayer(Some(LevelFilter::INFO)));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // Test filter on the other layer
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>)
+        .with(BasicLayer(Some(LevelFilter::INFO)).with_filter(LevelFilter::DEBUG));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>)
+        .with(BasicLayer(None).with_filter(LevelFilter::DEBUG));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::DEBUG),
+        "\n stack: {:#?}",
+        subscriber
+    );
+
+    // The `OFF` from `None` over overridden.
+    let subscriber = tracing_subscriber::registry()
+        .with(None::<LevelFilter>)
+        .with(BasicLayer(Some(LevelFilter::INFO)));
+    assert_eq!(
+        subscriber.max_level_hint(),
+        Some(LevelFilter::INFO),
+        "\n stack: {:#?}",
+        subscriber
+    );
+}
+
+/// Tests that the logic tested in `doesnt_override_none` works through the reload layer
+#[test]
+fn reload_works_with_none() {
+    let (layer1, handle1) = tracing_subscriber::reload::Layer::new(None::<BasicLayer>);
+    let (layer2, _handle2) = tracing_subscriber::reload::Layer::new(None::<BasicLayer>);
+
+    let subscriber = tracing_subscriber::registry().with(layer1).with(layer2);
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::OFF));
+
+    // reloading one should pass through correctly.
+    handle1.reload(Some(BasicLayer(None))).unwrap();
+    assert_eq!(subscriber.max_level_hint(), None);
+
+    // Check pass-through of an actual level as well
+    handle1
+        .reload(Some(BasicLayer(Some(LevelFilter::DEBUG))))
+        .unwrap();
+    assert_eq!(subscriber.max_level_hint(), Some(LevelFilter::DEBUG));
+}