feat: impl product name exists for category DB port

src/inventory/adapters/output/db/postgres/product_name_exists_for_category.rs

@@ -0,0 +1,78 @@
+// SPDX-FileCopyrightText: 2024 Aravinth Manivannan <realaravinth@batsense.net>
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+use super::InventoryDBPostgresAdapter;
+use crate::inventory::application::port::output::db::{
+    errors::*, product_name_exists_for_category::*,
+};
+use crate::inventory::domain::product_aggregate::*;
+
+#[async_trait::async_trait]
+impl ProductNameExistsForCategoryDBPort for InventoryDBPostgresAdapter {
+    async fn product_name_exists_for_category(&self, s: &Product) -> InventoryDBResult<bool> {
+        let res = sqlx::query!(
+            "SELECT EXISTS (
+                SELECT 1
+                    FROM cqrs_inventory_product_query
+                WHERE
+                    name = $1
+                AND
+                    category_id = $2
+            );",
+            s.name(),
+            s.category_id(),
+        )
+        .fetch_one(&self.pool)
+        .await?;
+        if let Some(x) = res.exists {
+            Ok(x)
+        } else {
+            Ok(false)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::inventory::adapters::output::db::postgres::product_id_exists::tests::create_dummy_product_record;
+    use crate::inventory::domain::add_product_command::tests::get_command;
+    use crate::utils::uuid::tests::UUID;
+
+    #[actix_rt::test]
+    async fn test_postgres_product_exists() {
+        let product_name = "foo_product";
+
+        let settings = crate::settings::tests::get_settings().await;
+        settings.create_db().await;
+        let db = super::InventoryDBPostgresAdapter::new(
+            sqlx::postgres::PgPool::connect(&settings.database.url)
+                .await
+                .unwrap(),
+        );
+
+        let cmd = get_command();
+
+        let product = ProductBuilder::default()
+            .name(product_name.into())
+            .description(cmd.description().as_ref().map(|s| s.to_string()))
+            .image(cmd.image().as_ref().map(|s| s.to_string()))
+            .sku_able(cmd.sku_able().clone())
+            .category_id(cmd.category_id().clone())
+            .product_id(UUID.clone())
+            .price(cmd.price().clone())
+            .build()
+            .unwrap();
+
+        // state doesn't exist
+        assert!(!db.product_name_exists_for_category(&product).await.unwrap());
+
+        create_dummy_product_record(&product, &db).await;
+
+        // state exists
+        assert!(db.product_name_exists_for_category(&product).await.unwrap());
+
+        settings.drop_db().await;
+    }
+}