WIP: use argument based logging configuration

Signed-off-by: Nick Gerace <nickagerace@gmail.com>

Cargo.toml

@@ -22,6 +22,7 @@ strip = true
 [dependencies]
 anyhow = { version = "1.0", features = ["backtrace"] }
 clap = { version = "4.5", features = ["derive"] }
+clap-verbosity-flag = "3.0.2"
 env_logger = { version = "0.11", features = [ "humantime" ], default-features = false }
 git2 = { version = "0.20", default-features = false }
 log = "0.4"

src/lib.rs

@@ -15,7 +15,6 @@ mod tests {
     use git2::Oid;
     use git2::Repository;
     use git2::Signature;
-    use log::LevelFilter;
     use pretty_assertions::assert_eq;
     use std::fs::File;
     use std::path::{Path, PathBuf};
@@ -27,11 +26,6 @@ mod tests {
     /// of nesting.
     #[test]
     fn scenario() -> anyhow::Result<()> {
-        env_logger::builder()
-            .is_test(true)
-            .filter_level(LevelFilter::Info)
-            .try_init()?;
-
         // Temporary directory structure:
         // └── root
         //     ├── one (repo)

src/main.rs

@@ -6,10 +6,10 @@
 
 use crate::config::{ColorMode, Config, DisplayMode};
 use crate::display::DisplayHarness;
+use clap_verbosity_flag::{InfoLevel, Verbosity};
 use gfold::RepositoryCollector;
 
 use clap::Parser;
-use env_logger::Builder;
 use log::{debug, LevelFilter};
 use std::{env, path::PathBuf};
 
@@ -46,20 +46,22 @@ struct Cli {
     /// ignore config file settings
     #[arg(short, long)]
     pub ignore_config_file: bool,
+
+    #[command(flatten)]
+    verbose: Verbosity<InfoLevel>,
 }
 
 /// Initializes the logger based on the debug flag and `RUST_LOG` environment variable, then
 /// parses CLI arguments and generates a [`Config`](config::Config) by merging configurations as needed,
 /// and finally collects results and displays them.
 fn main() -> anyhow::Result<()> {
-    if env::var("RUST_LOG").is_err() {
-        Builder::new().filter_level(LevelFilter::Off).init();
-    } else {
-        env_logger::init();
-    }
+    let cli = Cli::parse();
+
+    env_logger::Builder::new()
+        .filter_level(cli.verbose.log_level_filter())
+        .init();
     debug!("initialized logger");
 
-    let cli = Cli::parse();
     let mut config = if cli.ignore_config_file {
         Config::try_config_default()?
     } else {