keyfork-bin: initial commit

Cargo.lock

@@ -1674,6 +1674,7 @@ dependencies = [
  "card-backend-pcsc",
  "clap",
  "clap_complete",
+ "keyfork-bin",
  "keyfork-derive-openpgp",
  "keyfork-derive-util",
  "keyfork-entropy",
@@ -1692,6 +1693,13 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "keyfork-bin"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+]
+
 [[package]]
 name = "keyfork-crossterm"
 version = "0.27.1"

Cargo.toml

@@ -14,6 +14,7 @@ members = [
     "crates/qrcode/keyfork-qrcode",
     "crates/qrcode/keyfork-zbar",
     "crates/qrcode/keyfork-zbar-sys",
+    "crates/util/keyfork-bin",
     "crates/util/keyfork-crossterm",
     "crates/util/keyfork-entropy",
     "crates/util/keyfork-frame",

crates/keyfork/Cargo.toml

@@ -43,3 +43,4 @@ openpgp-card-sequoia = { version = "0.2.0", default-features = false }
 openpgp-card = "0.4.1"
 clap_complete = { version = "4.4.6", optional = true }
 sequoia-openpgp = { version = "1.17.0", default-features = false, features = ["compression"] }
+keyfork-bin = { version = "0.1.0", path = "../util/keyfork-bin" }

crates/keyfork/src/main.rs

@@ -6,21 +6,16 @@ use std::process::ExitCode;
 
 use clap::Parser;
 
+use keyfork_bin::{Bin, ClosureBin};
+
 mod cli;
 mod config;
 
 fn main() -> ExitCode {
-    let opts = cli::Keyfork::parse();
+    let bin = ClosureBin::new(|| {
+        let opts = cli::Keyfork::parse();
+        opts.command.handle(&opts)
+    });
 
-    if let Err(e) = opts.command.handle(&opts) {
+    bin.main()
-        eprintln!("Unable to run command: {e}");
-        let mut source = e.source();
-        while let Some(new_error) = source.take() {
-            eprintln!("Source: {new_error}");
-            source = new_error.source();
-        }
-        return ExitCode::FAILURE;
-    }
-
-    ExitCode::SUCCESS
 }

crates/util/keyfork-bin/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "keyfork-bin"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[dev-dependencies]
+anyhow = "1.0.79"

crates/util/keyfork-bin/src/lib.rs

@@ -0,0 +1,140 @@
+#![allow(clippy::needless_doctest_main)]
+
+//! A convenient trait for quickly writing binaries in a consistent pattern.
+//!
+//! # Examples
+//! ```rust
+//! use anyhow::anyhow;
+//! use keyfork_bin::Bin;
+//!
+//! struct Main;
+//!
+//! impl Bin for Main {
+//!     type Args = (String, String);
+//!
+//!     fn usage_hint(&self) -> Option<String> {
+//!         Some(String::from("<param1> <param2>"))
+//!     }
+//!
+//!     fn validate_args(&self, mut args: impl Iterator<Item = String>) -> keyfork_bin::ProcessResult<Self::Args> {
+//!         let arg1 = args.next().ok_or(anyhow!("missing argument 1"))?;
+//!         let arg2 = args.next().ok_or(anyhow!("missing argument 2"))?;
+//!         Ok((arg1, arg2))
+//!     }
+//!
+//!     fn run(&self, (arg1, arg2): Self::Args) -> keyfork_bin::ProcessResult {
+//!         println!("First argument: {arg1}");
+//!         println!("Second argument: {arg2}");
+//!         Ok(())
+//!     }
+//!#
+//!#    fn main(&self) -> std::process::ExitCode {
+//!#        self.main_inner([String::from("hello"), String::from("world")].into_iter())
+//!#    }
+//! }
+//!
+//! fn main() {
+//!     // Assume the program was called with something like "hello world"...
+//!     let bin = Main;
+//!     bin.main();
+//! }
+//! ```
+
+use std::process::ExitCode;
+
+/// A result that may contain any error.
+pub type ProcessResult<T = ()> = Result<T, Box<dyn std::error::Error>>;
+
+fn report_err(e: Box<dyn std::error::Error>) {
+    eprintln!("Unable to run command: {e}");
+    let mut source = e.source();
+    while let Some(new_error) = source.take() {
+        eprintln!("- Caused by: {new_error}");
+        source = new_error.source();
+    }
+}
+
+/// A trait for implementing the flow of a binary's execution.
+pub trait Bin {
+    /// The type for command-line arguments required by the function.
+    type Args;
+
+    /// A usage hint for how the arguments should be provided to the program.
+    fn usage_hint(&self) -> Option<String> {
+        None
+    }
+
+    /// Validate the arguments provided by the user into types required by the binary.
+    #[allow(clippy::missing_errors_doc)]
+    fn validate_args(&self, args: impl Iterator<Item = String>) -> ProcessResult<Self::Args>;
+
+    /// Run the binary 
+    #[allow(clippy::missing_errors_doc)]
+    fn run(&self, args: Self::Args) -> ProcessResult;
+
+    /// The default handler for running the binary and reporting any errors.
+    fn main(&self) -> ExitCode {
+        self.main_inner(std::env::args())
+    }
+
+    #[doc(hidden)]
+    fn main_inner(&self, mut args: impl Iterator<Item = String>) -> ExitCode {
+        let command = args.next();
+        let args = match self.validate_args(args) {
+            Ok(args) => args,
+            Err(e) => {
+                if let (Some(command), Some(hint)) = (command, self.usage_hint()) {
+                    eprintln!("Usage: {command} {hint}");
+                }
+                report_err(e);
+                return ExitCode::FAILURE;
+            }
+        };
+
+        if let Err(e) = self.run(args) {
+            report_err(e);
+            return ExitCode::FAILURE;
+        }
+
+        ExitCode::SUCCESS
+    }
+}
+
+/// A Bin that doesn't take any arguments.
+pub struct ClosureBin<F: Fn() -> ProcessResult> {
+    closure: F
+}
+
+impl<F> ClosureBin<F> where F: Fn() -> ProcessResult {
+    /// Create a new Bin from a closure.
+    ///
+    /// # Examples
+    /// ```rust
+    /// use keyfork_bin::{Bin, ClosureBin};
+    ///
+    /// let bin = ClosureBin::new(|| {
+    ///     println!("Hello, world!");
+    ///     Ok(())
+    /// });
+    ///
+    /// bin.main();
+    /// ```
+    pub fn new(closure: F) -> Self {
+        Self {
+            closure
+        }
+    }
+}
+
+impl<F> Bin for ClosureBin<F> where F: Fn() -> ProcessResult {
+    type Args = ();
+
+    fn validate_args(&self, _args: impl Iterator<Item = String>) -> ProcessResult<Self::Args> {
+        Ok(())
+    }
+
+    fn run(&self, _args: Self::Args) -> ProcessResult {
+        let c = &self.closure;
+        c()
+    }
+}