initial commit

exercises/05_ticket_v2/09_error_trait/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "error_trait"
+version = "0.1.0"
+edition = "2021"
+
+[dev-dependencies]
+common = { path = "../../../helpers/common" }
+static_assertions = "1.1.0"

exercises/05_ticket_v2/09_error_trait/src/lib.rs

@@ -0,0 +1,105 @@
+// TODO: Implement `Debug`, `Display` and `Error` for the `TicketNewError` enum.
+//  When implementing `Display`, you may want to use the `write!` macro from Rust's standard library.
+//  The docs for the `std::fmt` module are a good place to start and look for examples:
+//  https://doc.rust-lang.org/std/fmt/index.html#write
+
+enum TicketNewError {
+    TitleError(String),
+    DescriptionError(String),
+}
+
+// TODO: `easy_ticket` should panic when the title is invalid, using the error message
+//   stored inside the relevant variant of the `TicketNewError` enum.
+//   When the description is invalid, instead, it should use a default description:
+//   "Description not provided".
+fn easy_ticket(title: String, description: String, status: Status) -> Ticket {
+    todo!()
+}
+
+#[derive(Debug, PartialEq, Clone)]
+struct Ticket {
+    title: String,
+    description: String,
+    status: Status,
+}
+
+#[derive(Debug, PartialEq, Clone)]
+enum Status {
+    ToDo,
+    InProgress { assigned_to: String },
+    Done,
+}
+
+impl Ticket {
+    pub fn new(
+        title: String,
+        description: String,
+        status: Status,
+    ) -> Result<Ticket, TicketNewError> {
+        if title.is_empty() {
+            return Err(TicketNewError::TitleError(
+                "Title cannot be empty".to_string(),
+            ));
+        }
+        if title.len() > 50 {
+            return Err(TicketNewError::TitleError(
+                "Title cannot be longer than 50 bytes".to_string(),
+            ));
+        }
+        if description.is_empty() {
+            return Err(TicketNewError::DescriptionError(
+                "Description cannot be empty".to_string(),
+            ));
+        }
+        if description.len() > 500 {
+            return Err(TicketNewError::DescriptionError(
+                "Description cannot be longer than 500 bytes".to_string(),
+            ));
+        }
+
+        Ok(Ticket {
+            title,
+            description,
+            status,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use common::{overly_long_description, overly_long_title, valid_description, valid_title};
+    use static_assertions::assert_impl_one;
+
+    #[test]
+    #[should_panic(expected = "Title cannot be empty")]
+    fn title_cannot_be_empty() {
+        easy_ticket("".into(), valid_description(), Status::ToDo);
+    }
+
+    #[test]
+    fn template_description_is_used_if_empty() {
+        let ticket = easy_ticket(valid_title(), "".into(), Status::ToDo);
+        assert_eq!(ticket.description, "Description not provided");
+    }
+
+    #[test]
+    #[should_panic(expected = "Title cannot be longer than 50 bytes")]
+    fn title_cannot_be_longer_than_fifty_chars() {
+        easy_ticket(overly_long_title(), valid_description(), Status::ToDo);
+    }
+
+    #[test]
+    fn template_description_is_used_if_too_long() {
+        let ticket = easy_ticket(valid_title(), overly_long_description(), Status::ToDo);
+        assert_eq!(ticket.description, "Description not provided");
+    }
+
+    #[test]
+    fn display_is_correctly_implemented() {
+        let ticket = Ticket::new("".into(), valid_description(), Status::ToDo);
+        assert_eq!(format!("{}", ticket.unwrap_err()), "Title cannot be empty");
+    }
+
+    assert_impl_one!(TicketNewError: std::error::Error);
+}