Use clap environment variable

Author: theRookieCoder

Cargo.toml

@@ -51,7 +51,7 @@ tokio = { version = "1.43", default-features = false, features = [
     "rt-multi-thread",
     "macros",
 ] }
-clap = { version = "4.5", features = ["derive"] }
+clap = { version = "4.5", features = ["derive", "env"] }
 clap_complete = "4.5"
 parking_lot = "0.12"
 serde_json = "1.0"

src/cli.rs

@@ -11,7 +11,6 @@ use std::path::PathBuf;
 
 #[derive(Clone, Debug, Parser)]
 #[clap(author, version, about)]
-#[clap(arg_required_else_help = true)]
 pub struct Ferium {
     #[clap(subcommand)]
     pub subcommand: SubCommands,
@@ -23,12 +22,10 @@ pub struct Ferium {
     #[clap(long, short = 'p', default_value_t = DEFAULT_PARALLEL_NETWORK)]
     pub parallel_network: usize,
     /// Set a GitHub personal access token for increasing the GitHub API rate limit.
-    /// You can also use the environment variable `GITHUB_TOKEN`.
-    #[clap(long, visible_alias = "gh")]
+    #[clap(long, visible_alias = "gh", env = "GITHUB_TOKEN")]
     pub github_token: Option<String>,
     /// Set a custom Curseforge API key.
-    /// You can also use the environment variable `CURSEFORGE_API_KEY`.
-    #[clap(long, visible_alias = "cf")]
+    #[clap(long, visible_alias = "cf", env = "CURSEFORGE_API_KEY")]
     pub curseforge_api_key: Option<String>,
     /// Set the file to read the config from.
     /// This does not change the `cache` and `tmp` directories.

src/main.rs

@@ -9,10 +9,10 @@
     clippy::complexity,
     clippy::create_dir,
     clippy::unwrap_used,
-    clippy::expect_used, // use anyhow::Context instead
     clippy::correctness,
-    clippy::allow_attributes,
+    clippy::allow_attributes
 )]
+#![deny(clippy::expect_used, reason = "Use anyhow::Context instead")]
 #![warn(clippy::dbg_macro)]
 #![expect(clippy::multiple_crate_versions, clippy::too_many_lines)]
 
@@ -140,10 +140,14 @@ async fn actual_main(mut cli_app: Ferium) -> Result<()> {
     }
 
     if let Some(token) = cli_app.github_token {
-        set_var("GITHUB_TOKEN", token);
+        if !token.is_empty() {
+            set_var("GITHUB_TOKEN", token);
+        }
     }
     if let Some(key) = cli_app.curseforge_api_key {
-        set_var("CURSEFORGE_API_KEY", key);
+        if !key.is_empty() {
+            set_var("CURSEFORGE_API_KEY", key);
+        }
     }
     let _ = SEMAPHORE.set(tokio::sync::Semaphore::new(cli_app.parallel_network));