Merge pull request #79 from timburks/result

Modify run_with_result() to return Result<(), Box<dyn std::error::Error>>
ksk001100 · Dec 4, 2023 · 34c897a · 34c897a
2 parents 36c5f28 + 4f4db04
commit 34c897a
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Showing 7 changed files with 87 additions and 44 deletions.
diff --git a/README.md b/README.md
@@ -239,7 +239,7 @@ $ cli calc -op sub 10 6 3 2
 ### Top level error handling
 
 ```rust
-use seahorse::{ActionError, App, Context, Flag, FlagType};
+use seahorse::{App, Context, Flag, FlagType};
 use std::env;
 
 fn main() {
@@ -251,9 +251,7 @@ fn main() {
         .version(env!("CARGO_PKG_VERSION"))
         .action_with_result(|c: &Context| {
             if c.bool_flag("error") {
-                Err(ActionError {
-                    message: "ERROR...".to_string(),
-                })
+                Err(Box::new(Error))
             } else {
                 Ok(())
             }
@@ -266,11 +264,20 @@ fn main() {
 
     match app.run_with_result(args) {
         Ok(_) => println!("OK"),
-        Err(e) => match e {
-            ActionError { message } => println!("{}", message),
-        },
+        Err(e) => println!("{}", e),
     };
 }
+
+#[derive(Debug, Clone)]
+struct Error;
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "ERROR...")
+    }
+}
+
+impl std::error::Error for Error {}
 ```
 
 ```bash

diff --git a/examples/top_level_error_handling.rs b/examples/top_level_error_handling.rs
@@ -1,5 +1,6 @@
-use seahorse::{ActionError, App, Context, Flag, FlagType};
+use seahorse::{App, Context, Flag, FlagType};
 use std::env;
+use std::fmt;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
@@ -10,9 +11,7 @@ fn main() {
         .version(env!("CARGO_PKG_VERSION"))
         .action_with_result(|c: &Context| {
             if c.bool_flag("error") {
-                Err(ActionError {
-                    message: "ERROR...".to_string(),
-                })
+                Err(Box::new(Error))
             } else {
                 Ok(())
             }
@@ -25,8 +24,17 @@ fn main() {
 
     match app.run_with_result(args) {
         Ok(_) => println!("OK"),
-        Err(e) => match e {
-            ActionError { message } => println!("{}", message),
-        },
+        Err(e) => println!("{}", e),
     };
 }
+
+#[derive(Debug, Clone)]
+struct Error;
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "test error")
+    }
+}
+
+impl std::error::Error for Error {}
diff --git a/src/action.rs b/src/action.rs
@@ -1,4 +1,6 @@
 use crate::Context;
+use std::error::Error;
+use std::result::Result;
 
 /// Command and application action type
 ///
@@ -13,11 +15,4 @@ use crate::Context;
 /// ```
 pub type Action = fn(&Context);
 
-pub type ActionWithResult = fn(&Context) -> ActionResult;
-
-pub type ActionResult = Result<(), ActionError>;
-
-#[derive(Debug)]
-pub struct ActionError {
-    pub message: String,
-}
+pub type ActionWithResult = fn(&Context) -> Result<(), Box<dyn Error>>;
diff --git a/src/app.rs b/src/app.rs
@@ -1,6 +1,8 @@
 use crate::{
-    Action, ActionError, ActionResult, ActionWithResult, Command, Context, Flag, FlagType, Help,
+    error::ActionError, error::ActionErrorKind, Action, ActionWithResult, Command, Context, Flag,
+    FlagType, Help,
 };
+use std::error::Error;
 
 /// Multiple action application entry point
 #[derive(Default)]
@@ -252,7 +254,7 @@ impl App {
     pub fn run(&self, args: Vec<String>) {
         match self.run_with_result(args) {
             Ok(_) => return,
-            Err(e) => panic!("{}", e.message),
+            Err(e) => panic!("{}", e),
         }
     }
 
@@ -268,7 +270,7 @@ impl App {
     /// let app = App::new("cli");
     /// let result = app.run_with_result(args);
     /// ```
-    pub fn run_with_result(&self, args: Vec<String>) -> ActionResult {
+    pub fn run_with_result(&self, args: Vec<String>) -> Result<(), Box<dyn Error>> {
         let args = Self::normalized_args(args);
         let (cmd_v, args_v) = match args.len() {
             1 => args.split_at(1),
@@ -279,9 +281,9 @@ impl App {
             Some(c) => c,
             None => {
                 self.help();
-                return Err(ActionError {
-                    message: "unsupported command".to_string(),
-                });
+                return Err(Box::new(ActionError {
+                    kind: ActionErrorKind::NotFound,
+                }));
             }
         };
 
@@ -493,7 +495,8 @@ impl Help for App {
 
 #[cfg(test)]
 mod tests {
-    use crate::{Action, ActionError, ActionWithResult, App, Command, Context, Flag, FlagType};
+    use crate::{Action, ActionWithResult, App, Command, Context, Flag, FlagType};
+    use std::fmt;
 
     #[test]
     fn app_new_only_test() {
@@ -727,9 +730,7 @@ mod tests {
     #[should_panic]
     fn app_with_error_result_test() {
         let a: ActionWithResult = |_: &Context| {
-            return Err(ActionError {
-                message: "we expect this to fail".to_string(),
-            });
+            return Err(Box::new(Error));
         };
         let app = App::new("test").action_with_result(a);
         app.run(vec!["test".to_string()]);
@@ -748,9 +749,7 @@ mod tests {
     #[test]
     fn app_with_error_result_value_test() {
         let a: ActionWithResult = |_: &Context| {
-            return Err(ActionError {
-                message: "we expect this to fail".to_string(),
-            });
+            return Err(Box::new(Error));
         };
         let app = App::new("test").action_with_result(a);
         let result = app.run_with_result(vec!["test".to_string()]);
@@ -771,9 +770,7 @@ mod tests {
     #[should_panic]
     fn command_with_error_result_test() {
         let a: ActionWithResult = |_: &Context| {
-            return Err(ActionError {
-                message: "we expect this to fail".to_string(),
-            });
+            return Err(Box::new(Error));
         };
         let command = Command::new("hello").action_with_result(a);
         let app = App::new("test").command(command);
@@ -794,13 +791,22 @@ mod tests {
     #[test]
     fn command_with_error_result_value_test() {
         let a: ActionWithResult = |_: &Context| {
-            return Err(ActionError {
-                message: "we expect this to fail".to_string(),
-            });
+            return Err(Box::new(Error));
         };
         let command = Command::new("hello").action_with_result(a);
         let app = App::new("test").command(command);
         let result = app.run_with_result(vec!["test".to_string(), "hello".to_string()]);
         assert!(result.is_err());
     }
+
+    #[derive(Debug, Clone)]
+    struct Error;
+
+    impl fmt::Display for Error {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            write!(f, "test error")
+        }
+    }
+
+    impl std::error::Error for Error {}
 }
diff --git a/src/command.rs b/src/command.rs
@@ -1,4 +1,5 @@
-use crate::{Action, ActionResult, ActionWithResult, Context, Flag, FlagType, Help};
+use crate::{Action, ActionWithResult, Context, Flag, FlagType, Help};
+use std::error::Error;
 
 /// Application command type
 #[derive(Default)]
@@ -256,7 +257,7 @@ impl Command {
 
     /// Run command
     /// Call this function only from `App`
-    pub fn run_with_result(&self, args: Vec<String>) -> ActionResult {
+    pub fn run_with_result(&self, args: Vec<String>) -> Result<(), Box<dyn Error>> {
         let args = Self::normalized_args(args);
 
         match args.split_first() {

diff --git a/src/error.rs b/src/error.rs
@@ -1,6 +1,32 @@
 use std::error;
 use std::fmt;
 
+#[derive(Debug)]
+pub struct ActionError {
+    pub kind: ActionErrorKind,
+}
+
+impl fmt::Display for ActionError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.kind)
+    }
+}
+
+impl std::error::Error for ActionError {}
+
+#[derive(PartialEq, Clone, Debug)]
+pub enum ActionErrorKind {
+    NotFound,
+}
+
+impl fmt::Display for ActionErrorKind {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            ActionErrorKind::NotFound => f.write_str("NotFound"),
+        }
+    }
+}
+
 #[derive(PartialEq, Clone, Debug)]
 pub enum FlagError {
     NotFound,

diff --git a/src/lib.rs b/src/lib.rs
@@ -6,7 +6,7 @@ pub mod error;
 mod flag;
 mod help;
 
-pub use action::{Action, ActionError, ActionResult, ActionWithResult};
+pub use action::{Action, ActionWithResult};
 pub use app::App;
 pub use command::Command;
 pub use context::Context;