refactor: Reduce cognitive complexity of WebhookNotification handler. 2/2

Closes kemitix/git-next#49

Cargo.toml

@@ -3,7 +3,8 @@ resolver = "2"
 members = ["crates/*"]
 
 [workspace.package]
-version = "0.10.0"
+version = "0.10.0" # Update git-next-* under workspace.dependencies
+
 edition = "2021"
 license = "MIT"
 repository = "https://git.kemitix.net/kemitix/git-next"

crates/repo-actor/src/handlers/webhook_notification.rs

@@ -1,41 +1,27 @@
 //
 use actix::prelude::*;
 
-use crate::{self as actor, messages::WebhookNotification};
-use git_next_config as config;
-use git_next_git as git;
+use crate::{self as actor, messages::WebhookNotification, RepoActorLog};
+use git_next_config::WebhookAuth;
+use git_next_config::{
+    webhook::{push::Branch, Push},
+    BranchName,
+};
+use git_next_git::{self as git, Commit, ForgeLike};
 
 use tracing::{info, warn};
 
 impl Handler<WebhookNotification> for actor::RepoActor {
     type Result = ();
 
-    #[allow(clippy::cognitive_complexity)] // TODO: (#49) reduce complexity
     #[tracing::instrument(name = "RepoActor::WebhookMessage", skip_all, fields(token = %self.message_token, repo = %self.repo_details))]
     fn handle(&mut self, msg: WebhookNotification, ctx: &mut Self::Context) -> Self::Result {
-        let Some(expected_authorization) = &self.webhook_auth else {
-            actor::logger(&self.log, "server has no auth token");
-            warn!("Don't know what authorization to expect");
-            return;
-        };
         let Some(config) = &self.repo_details.repo_config else {
             actor::logger(&self.log, "server has no repo config");
             warn!("No repo config");
             return;
         };
-        if !self
-            .forge
-            .is_message_authorised(&msg, expected_authorization)
-        {
-            actor::logger(&self.log, "message authorisation is invalid");
-            warn!(
-                "Invalid authorization - expected {}",
-                expected_authorization
-            );
-            return;
-        }
-        if self.forge.should_ignore_message(&msg) {
-            actor::logger(&self.log, "forge sent ignorable message");
+        if validate_notification(&msg, &self.webhook_auth, &*self.forge, &self.log).is_err() {
             return;
         }
         let body = msg.body();
@@ -54,47 +40,41 @@ impl Handler<WebhookNotification> for actor::RepoActor {
                     );
                     return;
                 }
-                Some(config::webhook::push::Branch::Main) => {
-                    actor::logger(&self.log, "message is for main branch");
-                    let commit = git::Commit::from(push);
-                    if self.last_main_commit.as_ref() == Some(&commit) {
-                        actor::logger(&self.log, "not a new commit on main");
-                        info!(
-                            branch = %config.branches().main(),
-                            %commit,
-                            "Ignoring - already aware of branch at commit",
-                        );
+                Some(Branch::Main) => {
+                    if handle_push(
+                        push,
+                        config.branches().main(),
+                        &mut self.last_main_commit,
+                        &self.log,
+                    )
+                    .is_err()
+                    {
                         return;
+                    };
                 }
-                    self.last_main_commit.replace(commit);
-                }
-                Some(config::webhook::push::Branch::Next) => {
-                    actor::logger(&self.log, "message is for next branch");
-                    let commit = git::Commit::from(push);
-                    if self.last_next_commit.as_ref() == Some(&commit) {
-                        actor::logger(&self.log, "not a new commit on next");
-                        info!(
-                            branch = %config.branches().next(),
-                            %commit,
-                            "Ignoring - already aware of branch at commit",
-                        );
+                Some(Branch::Next) => {
+                    if handle_push(
+                        push,
+                        config.branches().next(),
+                        &mut self.last_next_commit,
+                        &self.log,
+                    )
+                    .is_err()
+                    {
                         return;
+                    };
                 }
-                    self.last_next_commit.replace(commit);
-                }
-                Some(config::webhook::push::Branch::Dev) => {
-                    actor::logger(&self.log, "message is for dev branch");
-                    let commit = git::Commit::from(push);
-                    if self.last_dev_commit.as_ref() == Some(&commit) {
-                        actor::logger(&self.log, "not a new commit on dev");
-                        info!(
-                            branch = %config.branches().dev(),
-                            %commit,
-                            "Ignoring - already aware of branch at commit",
-                        );
+                Some(Branch::Dev) => {
+                    if handle_push(
+                        push,
+                        config.branches().dev(),
+                        &mut self.last_dev_commit,
+                        &self.log,
+                    )
+                    .is_err()
+                    {
                         return;
-                    }
-                    self.last_dev_commit.replace(commit);
+                    };
                 }
             },
         }
@@ -110,3 +90,51 @@ impl Handler<WebhookNotification> for actor::RepoActor {
         );
     }
 }
+
+fn validate_notification(
+    msg: &WebhookNotification,
+    webhook_auth: &Option<WebhookAuth>,
+    forge: &dyn ForgeLike,
+    log: &Option<RepoActorLog>,
+) -> Result<(), ()> {
+    let Some(expected_authorization) = webhook_auth else {
+        actor::logger(log, "server has no auth token");
+        warn!("Don't know what authorization to expect");
+        return Err(());
+    };
+
+    if !forge.is_message_authorised(msg, expected_authorization) {
+        actor::logger(log, "message authorisation is invalid");
+        warn!(
+            "Invalid authorization - expected {}",
+            expected_authorization
+        );
+        return Err(());
+    }
+    if forge.should_ignore_message(msg) {
+        actor::logger(log, "forge sent ignorable message");
+        return Err(());
+    }
+    Ok(())
+}
+
+fn handle_push(
+    push: Push,
+    branch: BranchName,
+    last_commit: &mut Option<Commit>,
+    log: &Option<RepoActorLog>,
+) -> Result<(), ()> {
+    actor::logger(log, "message is for dev branch");
+    let commit = git::Commit::from(push);
+    if last_commit.as_ref() == Some(&commit) {
+        actor::logger(log, format!("not a new commit on {branch}"));
+        info!(
+            %branch ,
+            %commit,
+            "Ignoring - already aware of branch at commit",
+        );
+        return Err(());
+    }
+    last_commit.replace(commit);
+    Ok(())
+}

crates/repo-actor/src/tests/handlers/webhook_notification.rs

@@ -252,8 +252,9 @@ async fn when_message_is_push_already_seen_commit_to_main() -> TestResult {
     let forge_notification = ForgeNotification::new(forge_alias, repo_alias, headers, body);
     let repository_factory = MockRepositoryFactory::new();
     let commit = given::a_commit();
+    let main = repo_config.branches().main();
     let push = given::a_push()
-        .with_branch(repo_config.branches().main())
+        .with_branch(main.clone())
         .with_sha(commit.sha().to_string())
         .with_message(commit.message().to_string());
     let mut forge = given::a_forge();
@@ -283,7 +284,7 @@ async fn when_message_is_push_already_seen_commit_to_main() -> TestResult {
 
     //then
     log.no_message_contains("send")?;
-    log.require_message_containing("not a new commit on main")?;
+    log.require_message_containing(format!("not a new commit on {main}"))?;
     Ok(())
 }
 
@@ -300,8 +301,9 @@ async fn when_message_is_push_already_seen_commit_to_next() -> TestResult {
     let forge_notification = ForgeNotification::new(forge_alias, repo_alias, headers, body);
     let repository_factory = MockRepositoryFactory::new();
     let commit = given::a_commit();
+    let next = repo_config.branches().next();
     let push = given::a_push()
-        .with_branch(repo_config.branches().next())
+        .with_branch(next.clone())
         .with_sha(commit.sha().to_string())
         .with_message(commit.message().to_string());
     let mut forge = given::a_forge();
@@ -331,7 +333,7 @@ async fn when_message_is_push_already_seen_commit_to_next() -> TestResult {
 
     //then
     log.no_message_contains("send")?;
-    log.require_message_containing("not a new commit on next")?;
+    log.require_message_containing(format!("not a new commit on {next}"))?;
     Ok(())
 }
 
@@ -348,8 +350,9 @@ async fn when_message_is_push_already_seen_commit_to_dev() -> TestResult {
     let forge_notification = ForgeNotification::new(forge_alias, repo_alias, headers, body);
     let repository_factory = MockRepositoryFactory::new();
     let commit = given::a_commit();
+    let dev = repo_config.branches().dev();
     let push = given::a_push()
-        .with_branch(repo_config.branches().dev())
+        .with_branch(dev.clone())
         .with_sha(commit.sha().to_string())
         .with_message(commit.message().to_string());
     let mut forge = given::a_forge();
@@ -379,7 +382,7 @@ async fn when_message_is_push_already_seen_commit_to_dev() -> TestResult {
 
     //then
     log.no_message_contains("send")?;
-    log.require_message_containing("not a new commit on dev")?;
+    log.require_message_containing(format!("not a new commit on {dev}"))?;
     Ok(())
 }