feat!: Gate log crate behind feature flag

Cargo.toml

@@ -113,8 +113,12 @@ pre-release-replacements = [
 [badges]
 codecov = { repository = "clap-rs/clap-verbosity-flag" }
 
+[features]
+default = ["log"]
+log = ["dep:log"]
+
 [dependencies]
-log = "0.4.1"
+log = { version = "0.4.1", optional = true }
 clap = { version = "4.0.0", default-features = false, features = ["std", "derive"] }
 
 [dev-dependencies]
@@ -126,3 +130,15 @@ tracing-log = "0.2"
 
 [lints]
 workspace = true
+
+[[example]]
+name = "log"
+required-features = ["log"]
+
+[[example]]
+name = "log_level"
+required-features = ["log"]
+
+[[example]]
+name = "tracing"
+required-features = ["log"]

src/lib.rs

@@ -28,6 +28,7 @@
 //! #     verbose: Verbosity,
 //! # }
 //! let cli = Cli::parse();
+//! # #[cfg(feature = "log")]
 //! env_logger::Builder::new()
 //!     .filter_level(cli.verbose.log_level_filter())
 //!     .init();
@@ -63,8 +64,8 @@
 
 use std::fmt;
 
-pub use log::Level;
-pub use log::LevelFilter;
+#[cfg(feature = "log")]
+pub mod log;
 
 /// Logging flags to `#[command(flatten)]` into your CLI
 #[derive(clap::Args, Debug, Clone, Default)]
@@ -111,18 +112,6 @@ impl<L: LogLevel> Verbosity<L> {
         self.verbose != 0 || self.quiet != 0
     }
 
-    /// Get the log level.
-    ///
-    /// `None` means all output is disabled.
-    pub fn log_level(&self) -> Option<Level> {
-        self.filter().into()
-    }
-
-    /// Get the log level filter.
-    pub fn log_level_filter(&self) -> LevelFilter {
-        self.filter().into()
-    }
-
     /// If the user requested complete silence (i.e. not just no-logging).
     pub fn is_silent(&self) -> bool {
         self.filter() == VerbosityFilter::Off
@@ -135,6 +124,21 @@ impl<L: LogLevel> Verbosity<L> {
     }
 }
 
+#[cfg(feature = "log")]
+impl<L: LogLevel> Verbosity<L> {
+    /// Get the log level.
+    ///
+    /// `None` means all output is disabled.
+    pub fn log_level(&self) -> Option<log::Level> {
+        self.filter().into()
+    }
+
+    /// Get the log level filter.
+    pub fn log_level_filter(&self) -> log::LevelFilter {
+        self.filter().into()
+    }
+}
+
 impl<L: LogLevel> fmt::Display for Verbosity<L> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.filter().fmt(f)
@@ -217,58 +221,6 @@ impl fmt::Display for VerbosityFilter {
     }
 }
 
-impl From<VerbosityFilter> for LevelFilter {
-    fn from(filter: VerbosityFilter) -> Self {
-        match filter {
-            VerbosityFilter::Off => LevelFilter::Off,
-            VerbosityFilter::Error => LevelFilter::Error,
-            VerbosityFilter::Warn => LevelFilter::Warn,
-            VerbosityFilter::Info => LevelFilter::Info,
-            VerbosityFilter::Debug => LevelFilter::Debug,
-            VerbosityFilter::Trace => LevelFilter::Trace,
-        }
-    }
-}
-
-impl From<LevelFilter> for VerbosityFilter {
-    fn from(level: LevelFilter) -> Self {
-        match level {
-            LevelFilter::Off => Self::Off,
-            LevelFilter::Error => Self::Error,
-            LevelFilter::Warn => Self::Warn,
-            LevelFilter::Info => Self::Info,
-            LevelFilter::Debug => Self::Debug,
-            LevelFilter::Trace => Self::Trace,
-        }
-    }
-}
-
-impl From<VerbosityFilter> for Option<Level> {
-    fn from(filter: VerbosityFilter) -> Self {
-        match filter {
-            VerbosityFilter::Off => None,
-            VerbosityFilter::Error => Some(Level::Error),
-            VerbosityFilter::Warn => Some(Level::Warn),
-            VerbosityFilter::Info => Some(Level::Info),
-            VerbosityFilter::Debug => Some(Level::Debug),
-            VerbosityFilter::Trace => Some(Level::Trace),
-        }
-    }
-}
-
-impl From<Option<Level>> for VerbosityFilter {
-    fn from(level: Option<Level>) -> Self {
-        match level {
-            None => Self::Off,
-            Some(Level::Error) => Self::Error,
-            Some(Level::Warn) => Self::Warn,
-            Some(Level::Info) => Self::Info,
-            Some(Level::Debug) => Self::Debug,
-            Some(Level::Trace) => Self::Trace,
-        }
-    }
-}
-
 /// Default to [`VerbosityFilter::Error`]
 #[derive(Copy, Clone, Debug, Default)]
 pub struct ErrorLevel;
@@ -345,33 +297,6 @@ mod test {
         Cli::command().debug_assert();
     }
 
-    #[test]
-    fn log_level() {
-        let v = Verbosity::<OffLevel>::default();
-        assert_eq!(v.log_level(), None);
-        assert_eq!(v.log_level_filter(), LevelFilter::Off);
-
-        let v = Verbosity::<ErrorLevel>::default();
-        assert_eq!(v.log_level(), Some(Level::Error));
-        assert_eq!(v.log_level_filter(), LevelFilter::Error);
-
-        let v = Verbosity::<WarnLevel>::default();
-        assert_eq!(v.log_level(), Some(Level::Warn));
-        assert_eq!(v.log_level_filter(), LevelFilter::Warn);
-
-        let v = Verbosity::<InfoLevel>::default();
-        assert_eq!(v.log_level(), Some(Level::Info));
-        assert_eq!(v.log_level_filter(), LevelFilter::Info);
-
-        let v = Verbosity::<DebugLevel>::default();
-        assert_eq!(v.log_level(), Some(Level::Debug));
-        assert_eq!(v.log_level_filter(), LevelFilter::Debug);
-
-        let v = Verbosity::<TraceLevel>::default();
-        assert_eq!(v.log_level(), Some(Level::Trace));
-        assert_eq!(v.log_level_filter(), LevelFilter::Trace);
-    }
-
     /// Asserts that the filter is correct for the given verbosity and quiet values.
     #[track_caller]
     fn assert_filter<L: LogLevel>(verbose: u8, quiet: u8, expected: VerbosityFilter) {

src/log.rs

@@ -0,0 +1,91 @@
+// These re-exports of the log crate make it easy to use this crate without having to depend on the
+// log crate directly. See <https://github.com/clap-rs/clap-verbosity-flag/issues/54> for more
+// information.
+pub use log::{Level, LevelFilter};
+
+use crate::VerbosityFilter;
+
+impl From<VerbosityFilter> for LevelFilter {
+    fn from(filter: VerbosityFilter) -> Self {
+        match filter {
+            VerbosityFilter::Off => LevelFilter::Off,
+            VerbosityFilter::Error => LevelFilter::Error,
+            VerbosityFilter::Warn => LevelFilter::Warn,
+            VerbosityFilter::Info => LevelFilter::Info,
+            VerbosityFilter::Debug => LevelFilter::Debug,
+            VerbosityFilter::Trace => LevelFilter::Trace,
+        }
+    }
+}
+
+impl From<LevelFilter> for VerbosityFilter {
+    fn from(level: LevelFilter) -> Self {
+        match level {
+            LevelFilter::Off => Self::Off,
+            LevelFilter::Error => Self::Error,
+            LevelFilter::Warn => Self::Warn,
+            LevelFilter::Info => Self::Info,
+            LevelFilter::Debug => Self::Debug,
+            LevelFilter::Trace => Self::Trace,
+        }
+    }
+}
+
+impl From<VerbosityFilter> for Option<Level> {
+    fn from(filter: VerbosityFilter) -> Self {
+        match filter {
+            VerbosityFilter::Off => None,
+            VerbosityFilter::Error => Some(Level::Error),
+            VerbosityFilter::Warn => Some(Level::Warn),
+            VerbosityFilter::Info => Some(Level::Info),
+            VerbosityFilter::Debug => Some(Level::Debug),
+            VerbosityFilter::Trace => Some(Level::Trace),
+        }
+    }
+}
+
+impl From<Option<Level>> for VerbosityFilter {
+    fn from(level: Option<Level>) -> Self {
+        match level {
+            None => Self::Off,
+            Some(Level::Error) => Self::Error,
+            Some(Level::Warn) => Self::Warn,
+            Some(Level::Info) => Self::Info,
+            Some(Level::Debug) => Self::Debug,
+            Some(Level::Trace) => Self::Trace,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{DebugLevel, ErrorLevel, InfoLevel, OffLevel, TraceLevel, Verbosity, WarnLevel};
+
+    #[test]
+    fn log_level() {
+        let v = Verbosity::<OffLevel>::default();
+        assert_eq!(v.log_level(), None);
+        assert_eq!(v.log_level_filter(), LevelFilter::Off);
+
+        let v = Verbosity::<ErrorLevel>::default();
+        assert_eq!(v.log_level(), Some(Level::Error));
+        assert_eq!(v.log_level_filter(), LevelFilter::Error);
+
+        let v = Verbosity::<WarnLevel>::default();
+        assert_eq!(v.log_level(), Some(Level::Warn));
+        assert_eq!(v.log_level_filter(), LevelFilter::Warn);
+
+        let v = Verbosity::<InfoLevel>::default();
+        assert_eq!(v.log_level(), Some(Level::Info));
+        assert_eq!(v.log_level_filter(), LevelFilter::Info);
+
+        let v = Verbosity::<DebugLevel>::default();
+        assert_eq!(v.log_level(), Some(Level::Debug));
+        assert_eq!(v.log_level_filter(), LevelFilter::Debug);
+
+        let v = Verbosity::<TraceLevel>::default();
+        assert_eq!(v.log_level(), Some(Level::Trace));
+        assert_eq!(v.log_level_filter(), LevelFilter::Trace);
+    }
+}