100 exercises to learn Rust

exercises/05_ticket_v2/14_source/src/lib.rs

@@ -0,0 +1,76 @@
+use crate::status::Status;
+
+// We've seen how to declare modules in one of the earliest exercises, but
+// we haven't seen how to extract them into separate files.
+// Let's fix that now!
+//
+// In the simplest case, when the extracted module is a single file, it is enough to
+// create a new file with the same name as the module and move the module content there.
+// The module file should be placed in the same directory as the file that declares the module.
+// In this case, `src/lib.rs`, thus `status.rs` should be placed in the `src` directory.
+mod status;
+
+// TODO: Add a new error variant to `TicketNewError` for when the status string is invalid.
+//   When calling `source` on an error of that variant, it should return a `ParseStatusError` rather than `None`.
+
+#[derive(Debug, thiserror::Error)]
+pub enum TicketNewError {
+    #[error("Title cannot be empty")]
+    TitleCannotBeEmpty,
+    #[error("Title cannot be longer than 50 characters")]
+    TitleTooLong,
+    #[error("Description cannot be empty")]
+    DescriptionCannotBeEmpty,
+    #[error("Description cannot be longer than 500 characters")]
+    DescriptionTooLong,
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct Ticket {
+    title: String,
+    description: String,
+    status: Status,
+}
+
+impl Ticket {
+    pub fn new(title: String, description: String, status: String) -> Result<Self, TicketNewError> {
+        if title.is_empty() {
+            return Err(TicketNewError::TitleCannotBeEmpty);
+        }
+        if title.len() > 50 {
+            return Err(TicketNewError::TitleTooLong);
+        }
+        if description.is_empty() {
+            return Err(TicketNewError::DescriptionCannotBeEmpty);
+        }
+        if description.len() > 500 {
+            return Err(TicketNewError::DescriptionTooLong);
+        }
+
+        // TODO: Parse the status string into a `Status` enum.
+
+        Ok(Ticket {
+            title,
+            description,
+            status,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use common::{valid_description, valid_title};
+    use std::error::Error;
+
+    use super::*;
+
+    #[test]
+    fn invalid_status() {
+        let err = Ticket::new(valid_title(), valid_description(), "invalid".into()).unwrap_err();
+        assert_eq!(
+            err.to_string(),
+            "`invalid` is not a valid status. Use one of: ToDo, InProgress, Done"
+        );
+        assert!(err.source().is_some());
+    }
+}