Add --config as a command-line option (#422)

README.md

@@ -94,6 +94,8 @@ Arguments:
   <FILES>...
 
 Options:
+      --config <CONFIG>
+          Path to the `pyproject.toml` file to use for configuration
   -v, --verbose
           Enable verbose logging
   -q, --quiet
@@ -132,6 +134,8 @@ Options:
           Regular expression matching the name of dummy variables
       --target-version <TARGET_VERSION>
           The minimum Python version that should be supported
+      --stdin-filename <STDIN_FILENAME>
+          The name of the file when passing it through stdin
   -h, --help
           Print help information
   -V, --version

src/cli.rs

@@ -17,6 +17,9 @@ use crate::RawSettings;
 pub struct Cli {
     #[arg(required = true)]
     pub files: Vec<PathBuf>,
+    /// Path to the `pyproject.toml` file to use for configuration.
+    #[arg(long)]
+    pub config: Option<PathBuf>,
     /// Enable verbose logging.
     #[arg(short, long)]
     pub verbose: bool,

src/main.rs

@@ -216,7 +216,9 @@ fn inner_main() -> Result<ExitCode> {
         Some(path) => debug!("Found project root at: {:?}", path),
         None => debug!("Unable to identify project root; assuming current directory..."),
     };
-    let pyproject = pyproject::find_pyproject_toml(&project_root);
+    let pyproject = cli
+        .config
+        .or_else(|| pyproject::find_pyproject_toml(&project_root));
     match &pyproject {
         Some(path) => debug!("Found pyproject.toml at: {:?}", path),
         None => debug!("Unable to find pyproject.toml; using default settings..."),