add 400+ unit tests for domain and application layers

Extract ReviewLogger trait to decouple import/integrations
from diary::log_review (cross-module coupling smell).

Add in-memory fakes for all repository ports, enabling
isolated testing of every use case module without a database.

Coverage: domain+application 22% → 80%, 427 tests.

crates/application/src/goals/create.rs

@@ -54,3 +54,7 @@ pub async fn execute(
         current_count,
     })
 }
+
+#[cfg(test)]
+#[path = "tests/create.rs"]
+mod tests;

crates/application/src/goals/delete.rs

@@ -26,3 +26,7 @@ pub async fn execute(ctx: &AppContext, cmd: DeleteGoalCommand) -> Result<(), Dom
 
     Ok(())
 }
+
+#[cfg(test)]
+#[path = "tests/delete.rs"]
+mod tests;

crates/application/src/goals/get.rs

@@ -28,3 +28,7 @@ pub async fn execute(
         current_count,
     }))
 }
+
+#[cfg(test)]
+#[path = "tests/get.rs"]
+mod tests;

crates/application/src/goals/list.rs

@@ -25,3 +25,7 @@ pub async fn execute(
 
     Ok(result)
 }
+
+#[cfg(test)]
+#[path = "tests/list.rs"]
+mod tests;

crates/application/src/goals/tests/create.rs

@@ -0,0 +1,117 @@
+use std::sync::Arc;
+
+use domain::events::DomainEvent;
+use domain::testing::{InMemoryGoalRepository, NoopEventPublisher};
+use uuid::Uuid;
+
+use crate::goals::{commands::CreateGoalCommand, create};
+use crate::test_helpers::TestContextBuilder;
+
+#[tokio::test]
+async fn creates_goal_and_returns_progress() {
+    let goals = InMemoryGoalRepository::new();
+    goals.set_review_count(Uuid::nil(), 2025, 5);
+    let events = NoopEventPublisher::new();
+    let ctx = TestContextBuilder::new()
+        .with_goal(Arc::clone(&goals) as _)
+        .with_event_publisher(Arc::clone(&events) as _)
+        .build();
+
+    let result = create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 50,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert_eq!(result.goal.year(), 2025);
+    assert_eq!(result.goal.target_count(), 50);
+    assert_eq!(result.current_count, 5);
+    assert_eq!(goals.count(), 1);
+}
+
+#[tokio::test]
+async fn emits_goal_created_event() {
+    let events = NoopEventPublisher::new();
+    let ctx = TestContextBuilder::new()
+        .with_event_publisher(Arc::clone(&events) as _)
+        .build();
+
+    create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 10,
+        },
+    )
+    .await
+    .unwrap();
+
+    let published = events.published();
+    assert!(
+        published
+            .iter()
+            .any(|e| matches!(e, DomainEvent::GoalCreated { year: 2025, .. }))
+    );
+}
+
+#[tokio::test]
+async fn rejects_duplicate_year() {
+    let ctx = TestContextBuilder::new().build();
+    let cmd = CreateGoalCommand {
+        user_id: Uuid::nil(),
+        year: 2025,
+        target_count: 10,
+    };
+
+    create::execute(&ctx, cmd).await.unwrap();
+
+    let result = create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 20,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}
+
+#[tokio::test]
+async fn rejects_year_before_2020() {
+    let ctx = TestContextBuilder::new().build();
+    let result = create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2019,
+            target_count: 10,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}
+
+#[tokio::test]
+async fn rejects_zero_target() {
+    let ctx = TestContextBuilder::new().build();
+    let result = create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 0,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}

crates/application/src/goals/tests/delete.rs

@@ -0,0 +1,59 @@
+use std::sync::Arc;
+
+use domain::testing::{InMemoryGoalRepository, NoopEventPublisher};
+use uuid::Uuid;
+
+use crate::goals::{
+    commands::{CreateGoalCommand, DeleteGoalCommand},
+    create, delete,
+};
+use crate::test_helpers::TestContextBuilder;
+
+#[tokio::test]
+async fn deletes_existing_goal() {
+    let goals = InMemoryGoalRepository::new();
+    let events = NoopEventPublisher::new();
+    let ctx = TestContextBuilder::new()
+        .with_goal(Arc::clone(&goals) as _)
+        .with_event_publisher(Arc::clone(&events) as _)
+        .build();
+
+    create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 10,
+        },
+    )
+    .await
+    .unwrap();
+    assert_eq!(goals.count(), 1);
+
+    delete::execute(
+        &ctx,
+        DeleteGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert_eq!(goals.count(), 0);
+}
+
+#[tokio::test]
+async fn fails_when_not_found() {
+    let ctx = TestContextBuilder::new().build();
+    let result = delete::execute(
+        &ctx,
+        DeleteGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}

crates/application/src/goals/tests/get.rs

@@ -0,0 +1,48 @@
+use uuid::Uuid;
+
+use crate::goals::{commands::CreateGoalCommand, create, get, queries::GetGoalQuery};
+use crate::test_helpers::TestContextBuilder;
+
+#[tokio::test]
+async fn returns_goal_when_exists() {
+    let ctx = TestContextBuilder::new().build();
+    create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 50,
+        },
+    )
+    .await
+    .unwrap();
+
+    let result = get::execute(
+        &ctx,
+        GetGoalQuery {
+            user_id: Uuid::nil(),
+            year: 2025,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert!(result.is_some());
+    assert_eq!(result.unwrap().goal.target_count(), 50);
+}
+
+#[tokio::test]
+async fn returns_none_when_missing() {
+    let ctx = TestContextBuilder::new().build();
+    let result = get::execute(
+        &ctx,
+        GetGoalQuery {
+            user_id: Uuid::nil(),
+            year: 2025,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert!(result.is_none());
+}

crates/application/src/goals/tests/list.rs

@@ -0,0 +1,47 @@
+use uuid::Uuid;
+
+use crate::goals::{commands::CreateGoalCommand, create, list, queries::ListGoalsQuery};
+use crate::test_helpers::TestContextBuilder;
+
+#[tokio::test]
+async fn returns_empty_when_no_goals() {
+    let ctx = TestContextBuilder::new().build();
+    let result = list::execute(
+        &ctx,
+        ListGoalsQuery {
+            user_id: Uuid::nil(),
+        },
+    )
+    .await
+    .unwrap();
+
+    assert!(result.is_empty());
+}
+
+#[tokio::test]
+async fn returns_all_goals_for_user() {
+    let ctx = TestContextBuilder::new().build();
+    for year in [2023, 2024, 2025] {
+        create::execute(
+            &ctx,
+            CreateGoalCommand {
+                user_id: Uuid::nil(),
+                year,
+                target_count: 10,
+            },
+        )
+        .await
+        .unwrap();
+    }
+
+    let result = list::execute(
+        &ctx,
+        ListGoalsQuery {
+            user_id: Uuid::nil(),
+        },
+    )
+    .await
+    .unwrap();
+
+    assert_eq!(result.len(), 3);
+}

crates/application/src/goals/tests/update.rs

@@ -0,0 +1,78 @@
+use uuid::Uuid;
+
+use crate::goals::{
+    commands::{CreateGoalCommand, UpdateGoalCommand},
+    create, update,
+};
+use crate::test_helpers::TestContextBuilder;
+
+#[tokio::test]
+async fn updates_target_count() {
+    let ctx = TestContextBuilder::new().build();
+    create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 10,
+        },
+    )
+    .await
+    .unwrap();
+
+    let result = update::execute(
+        &ctx,
+        UpdateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 100,
+        },
+    )
+    .await
+    .unwrap();
+
+    assert_eq!(result.goal.target_count(), 100);
+}
+
+#[tokio::test]
+async fn fails_when_goal_not_found() {
+    let ctx = TestContextBuilder::new().build();
+    let result = update::execute(
+        &ctx,
+        UpdateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 10,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}
+
+#[tokio::test]
+async fn rejects_zero_target() {
+    let ctx = TestContextBuilder::new().build();
+    create::execute(
+        &ctx,
+        CreateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 10,
+        },
+    )
+    .await
+    .unwrap();
+
+    let result = update::execute(
+        &ctx,
+        UpdateGoalCommand {
+            user_id: Uuid::nil(),
+            year: 2025,
+            target_count: 0,
+        },
+    )
+    .await;
+
+    assert!(result.is_err());
+}

crates/application/src/goals/update.rs

@@ -42,3 +42,7 @@ pub async fn execute(
         current_count,
     })
 }
+
+#[cfg(test)]
+#[path = "tests/update.rs"]
+mod tests;