feat: add a RequestBuilder to create Request messages

A builder interface is easier to use I find.

Signed-off-by: Lars Wirzenius <liw@liw.fi>

4 files changed, 110 insertions, 60 deletions

diff --git a/src/bin/broker-messages.rs b/src/bin/broker-messages.rs
index 8e47ee1..deb3112 100644
--- a/src/bin/broker-messages.rs
+++ b/src/bin/broker-messages.rs
@@ -2,7 +2,7 @@ use radicle::git::RefString;
 use radicle::Profile;
 use radicle_ci_broker::{
     event::BrokerEvent,
-    msg::{Oid, RepoId, Request, Response, RunId, RunResult},
+    msg::{Oid, RepoId, RequestBuilder, Response, RunId, RunResult},
 };
 
 fn main() {
@@ -17,7 +17,11 @@ fn main() {
         old: None,
     };
     let profile = Profile::load().expect("create profile");
-    let trigger = Request::trigger(&profile, &be).expect("create trigger");
+    let trigger = RequestBuilder::default()
+        .profile(&profile)
+        .broker_event(&be)
+        .build_trigger()
+        .expect("create trigger");
     println!("Trigger request:\n{}\n", trigger);
 
     let triggered = Response::triggered(RunId::from("any-string-works-as-run-id"));
diff --git a/src/bin/ci-broker.rs b/src/bin/ci-broker.rs
index 9ea58ff..d8cf766 100644
--- a/src/bin/ci-broker.rs
+++ b/src/bin/ci-broker.rs
@@ -14,7 +14,7 @@ use radicle_ci_broker::{
     config::Config,
     error::BrokerError,
     event::NodeEventSource,
-    msg::Request,
+    msg::RequestBuilder,
     pages::{PageBuilder, StatusPage},
 };
 
@@ -101,7 +101,10 @@ fn fallible_main() -> Result<(), BrokerError> {
         for e in source.event()? {
             page.broker_event(&e);
             debug!("broker event {e:#?}");
-            let req = Request::trigger(&profile, &e)?;
+            let req = RequestBuilder::default()
+                .profile(&profile)
+                .broker_event(&e)
+                .build_trigger()?;
             broker.execute_ci(&req, &mut page)?;
         }
     }
diff --git a/src/msg.rs b/src/msg.rs
index 63fdccf..067faa2 100644
--- a/src/msg.rs
+++ b/src/msg.rs
@@ -95,62 +95,31 @@ impl fmt::Display for RunResult {
     }
 }
 
-/// A request message sent by the broker to its adapter child process.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(tag = "request")]
-#[serde(rename_all = "snake_case")]
-#[non_exhaustive]
-pub enum Request {
-    /// Trigger a run.
-    Trigger {
-        /// Common fields for all message variants.
-        #[serde(flatten)]
-        common: EventCommonFields,
-
-        /// The push event, if any.
-        #[serde(flatten)]
-        push: Option<PushEvent>,
-
-        /// The patch event, if any.
-        #[serde(flatten)]
-        patch: Option<PatchEvent>,
-    },
+/// Build a [`Request`].
+#[derive(Debug, Default)]
+pub struct RequestBuilder<'a> {
+    profile: Option<&'a Profile>,
+    event: Option<&'a BrokerEvent>,
 }
 
-impl Request {
-    /// Repository that the event concerns.
-    pub fn repo(&self) -> RepoId {
-        match self {
-            Self::Trigger {
-                common,
-                push: _,
-                patch: _,
-            } => common.repository.id,
-        }
+impl<'a> RequestBuilder<'a> {
+    /// Set the node profile to use.
+    pub fn profile(mut self, profile: &'a Profile) -> Self {
+        self.profile = Some(profile);
+        self
     }
 
-    /// Return the commit the event concerns. In other words, the
-    /// commit that CI should run against.
-    pub fn commit(&self) -> Oid {
-        match self {
-            Self::Trigger {
-                common: _,
-                push,
-                patch,
-            } => {
-                if let Some(push) = push {
-                    *push.commits.last().unwrap()
-                } else if let Some(patch) = patch {
-                    *patch.patch.commits.last().unwrap()
-                } else {
-                    panic!("neither push not panic: {self:#?}");
-                }
-            }
-        }
+    /// Set the broker event to use.
+    pub fn broker_event(mut self, event: &'a BrokerEvent) -> Self {
+        self.event = Some(event);
+        self
     }
 
-    /// Create a request event to trigger a run.
-    pub fn trigger(profile: &Profile, event: &BrokerEvent) -> Result<Self, MessageError> {
+    /// Create a [`Request::Trigger`] message.
+    pub fn build_trigger(self) -> Result<Request, MessageError> {
+        let profile = self.profile.ok_or(MessageError::NoProfile)?;
+        let event = self.event.ok_or(MessageError::NoEvent)?;
+
         let BrokerEvent::RefChanged {
             rid,
             name,
@@ -268,12 +237,67 @@ impl Request {
             },
         };
 
-        Ok(Self::Trigger {
+        Ok(Request::Trigger {
             common,
             push: push_info,
             patch: patch_info,
         })
     }
+}
+
+/// A request message sent by the broker to its adapter child process.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "request")]
+#[serde(rename_all = "snake_case")]
+#[non_exhaustive]
+pub enum Request {
+    /// Trigger a run.
+    Trigger {
+        /// Common fields for all message variants.
+        #[serde(flatten)]
+        common: EventCommonFields,
+
+        /// The push event, if any.
+        #[serde(flatten)]
+        push: Option<PushEvent>,
+
+        /// The patch event, if any.
+        #[serde(flatten)]
+        patch: Option<PatchEvent>,
+    },
+}
+
+impl Request {
+    /// Repository that the event concerns.
+    pub fn repo(&self) -> RepoId {
+        match self {
+            Self::Trigger {
+                common,
+                push: _,
+                patch: _,
+            } => common.repository.id,
+        }
+    }
+
+    /// Return the commit the event concerns. In other words, the
+    /// commit that CI should run against.
+    pub fn commit(&self) -> Oid {
+        match self {
+            Self::Trigger {
+                common: _,
+                push,
+                patch,
+            } => {
+                if let Some(push) = push {
+                    *push.commits.last().unwrap()
+                } else if let Some(patch) = patch {
+                    *patch.patch.commits.last().unwrap()
+                } else {
+                    panic!("neither push not panic: {self:#?}");
+                }
+            }
+        }
+    }
 
     /// Serialize the request as a single-line JSON, including the
     /// newline. This is meant for the broker to use.
@@ -547,6 +571,14 @@ impl Response {
 /// All possible errors from the CI broker messages.
 #[derive(Debug, thiserror::Error)]
 pub enum MessageError {
+    /// [`RequestBuilder`] does not have profile set.
+    #[error("RequestBuilder must have profile set")]
+    NoProfile,
+
+    /// [`RequestBuilder`] does not have event set.
+    #[error("RequestBuilder must have broker event set")]
+    NoEvent,
+
     /// Failed to serialize a request message as JSON. This should
     /// never happen and likely indicates a programming failure.
     #[error("failed to serialize a request into JSON to a file handle")]
@@ -606,7 +638,7 @@ pub enum MessageError {
 #[cfg(test)]
 pub mod tests {
     use crate::event::BrokerEvent;
-    use crate::msg::Request;
+    use crate::msg::{Request, RequestBuilder};
     use radicle::git::raw::Oid;
     use radicle::git::RefString;
     use radicle::patch::{MergeTarget, Patches};
@@ -637,7 +669,11 @@ pub mod tests {
             old: Some(repo_head),
         };
 
-        let req = Request::trigger(&profile, &be).expect("expect request trigger");
+        let req = RequestBuilder::default()
+            .profile(&profile)
+            .broker_event(&be)
+            .build_trigger()
+            .unwrap();
         let Request::Trigger {
             common,
             push,
@@ -702,7 +738,11 @@ pub mod tests {
             old: None,
         };
 
-        let req = Request::trigger(&profile, &be)?;
+        let req = RequestBuilder::default()
+            .profile(&profile)
+            .broker_event(&be)
+            .build_trigger()
+            .unwrap();
         let Request::Trigger {
             common,
             push,
diff --git a/src/test.rs b/src/test.rs
index f1e1bdd..7d1f9c1 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -6,7 +6,7 @@ use std::{
 
 use crate::adapter::Adapter;
 use crate::event::BrokerEvent;
-use crate::msg::Request;
+use crate::msg::{Request, RequestBuilder};
 use radicle::crypto::ssh::Keystore;
 use radicle::crypto::test::signer::MockSigner;
 use radicle::crypto::Signer;
@@ -77,7 +77,10 @@ pub fn trigger_request() -> TestResult<Request> {
         old: Some(repo_head),
     };
 
-    Ok(Request::trigger(&profile, &be)?)
+    Ok(RequestBuilder::default()
+        .profile(&profile)
+        .broker_event(&be)
+        .build_trigger()?)
 }
 
 pub fn mock_adapter(filename: &Path, script: &str) -> TestResult<Adapter> {