chore: fresh DBs for mutation tests (#247)

<!-- The PR description should answer 2 (maybe 3) important questions:
-->

### What

We want to test mutations. To do this, we need fresh databases we can
mutate and discard. This creates helpers for creating a fresh database.

I think the abstraction could be improved, but hopefully it's not too
arduous for the test writer.

### How

Helpers to 
- make a UUID
- create a DB with UUID as name
- connect to that DB, import chinook
- return new connection string
- delete it afterwards

---------

Co-authored-by: Gil Mizrahi <[email protected]>

.gitignore

@@ -23,3 +23,6 @@ generated/
 # nix outputs
 /result
 /result-*
+
+# deployments created for testing
+static/temp-deploys/*.json

crates/ndc-citus/tests/common/mod.rs

@@ -12,7 +12,7 @@ pub async fn create_router() -> axum::Router {
 
     // work out where the deployment configs live
     let test_deployment_file =
-        tests_common::deployment::get_deployment_file(CHINOOK_DEPLOYMENT_PATH);
+        tests_common::deployment::helpers::get_path_from_project_root(CHINOOK_DEPLOYMENT_PATH);
 
     // initialise server state with the static configuration.
     let state = ndc_sdk::default_main::init_server_state::<connector::Citus>(

crates/ndc-citus/tests/configuration_tests.rs

@@ -12,7 +12,7 @@ use similar_asserts::assert_eq;
 // it should be switched the to the Citus one later
 use ndc_postgres::configuration;
 
-use tests_common::deployment::get_deployment_file;
+use tests_common::deployment::helpers::get_path_from_project_root;
 
 const CONFIGURATION_QUERY: &str = include_str!("../../ndc-postgres/src/configuration.sql");
 
@@ -26,7 +26,7 @@ async fn test_configure() {
     };
 
     let expected_value: serde_json::Value = {
-        let file = fs::File::open(get_deployment_file(common::CHINOOK_DEPLOYMENT_PATH))
+        let file = fs::File::open(get_path_from_project_root(common::CHINOOK_DEPLOYMENT_PATH))
             .expect("fs::File::open");
         let mut result: serde_json::Value =
             serde_json::from_reader(file).expect("serde_json::from_reader");

crates/ndc-cockroach/tests/common/mod.rs

@@ -11,7 +11,7 @@ pub async fn create_router() -> axum::Router {
 
     // work out where the deployment configs live
     let test_deployment_file =
-        tests_common::deployment::get_deployment_file(CHINOOK_DEPLOYMENT_PATH);
+        tests_common::deployment::helpers::get_path_from_project_root(CHINOOK_DEPLOYMENT_PATH);
 
     // initialise server state with the static configuration.
     let state = ndc_sdk::default_main::init_server_state::<connector::Cockroach>(

crates/ndc-cockroach/tests/configuration_tests.rs

@@ -8,7 +8,7 @@ use std::fs;
 
 use similar_asserts::assert_eq;
 
-use tests_common::deployment::get_deployment_file;
+use tests_common::deployment::helpers::get_path_from_project_root;
 
 const CONFIGURATION_QUERY: &str = include_str!("../src/configuration.sql");
 
@@ -22,7 +22,7 @@ async fn test_configure() {
     };
 
     let expected_value: serde_json::Value = {
-        let file = fs::File::open(get_deployment_file(common::CHINOOK_DEPLOYMENT_PATH))
+        let file = fs::File::open(get_path_from_project_root(common::CHINOOK_DEPLOYMENT_PATH))
             .expect("fs::File::open");
         let mut result: serde_json::Value =
             serde_json::from_reader(file).expect("serde_json::from_reader");

crates/ndc-postgres/tests/common/mod.rs

@@ -6,11 +6,16 @@ pub const CHINOOK_DEPLOYMENT_PATH: &str = "static/chinook-deployment.json";
 
 /// Creates a router with a fresh state from the test deployment.
 pub async fn create_router() -> axum::Router {
+    create_router_from_deployment(CHINOOK_DEPLOYMENT_PATH).await
+}
+
+/// Creates a router with a fresh state from a deployment file path
+pub async fn create_router_from_deployment(deployment_path: &str) -> axum::Router {
     let _ = env_logger::builder().is_test(true).try_init();
 
     // work out where the deployment configs live
     let test_deployment_file =
-        tests_common::deployment::get_deployment_file(CHINOOK_DEPLOYMENT_PATH);
+        tests_common::deployment::helpers::get_path_from_project_root(deployment_path);
 
     // initialise server state with the static configuration.
     let state = ndc_sdk::default_main::init_server_state::<connector::Postgres>(

crates/ndc-postgres/tests/configuration_tests.rs

@@ -10,7 +10,7 @@ use similar_asserts::assert_eq;
 
 use ndc_postgres::configuration;
 
-use tests_common::deployment::get_deployment_file;
+use tests_common::deployment::helpers::get_path_from_project_root;
 
 const POSTGRESQL_CONNECTION_STRING: &str = "postgresql://postgres:password@localhost:64002";
 const CHINOOK_DEPLOYMENT_PATH: &str = "static/chinook-deployment.json";
@@ -26,8 +26,8 @@ async fn test_configure() {
     };
 
     let expected_value: serde_json::Value = {
-        let file =
-            fs::File::open(get_deployment_file(CHINOOK_DEPLOYMENT_PATH)).expect("fs::File::open");
+        let file = fs::File::open(get_path_from_project_root(CHINOOK_DEPLOYMENT_PATH))
+            .expect("fs::File::open");
         let mut result: serde_json::Value =
             serde_json::from_reader(file).expect("serde_json::from_reader");
 

crates/ndc-postgres/tests/mutation_tests.rs

@@ -0,0 +1,29 @@
+pub mod common;
+use tests_common::deployment::{clean_up_deployment, create_fresh_deployment};
+use tests_common::request::run_query;
+
+pub const POSTGRESQL_CONNECTION_STRING: &str = "postgresql://postgres:password@localhost:64002";
+pub const CHINOOK_DEPLOYMENT_PATH: &str = "static/chinook-deployment.json";
+
+/// create a fresh db then run a query against it
+mod basic {
+    use super::{clean_up_deployment, create_fresh_deployment, run_query};
+
+    #[tokio::test]
+    async fn select_by_pk() {
+        let deployment = create_fresh_deployment(
+            super::POSTGRESQL_CONNECTION_STRING,
+            super::CHINOOK_DEPLOYMENT_PATH,
+        )
+        .await;
+
+        let result = run_query(
+            super::common::create_router_from_deployment(&deployment.deployment_path).await,
+            "select_by_pk",
+        )
+        .await;
+
+        clean_up_deployment(deployment).await;
+        insta::assert_json_snapshot!(result)
+    }
+}

crates/ndc-postgres/tests/snapshots/mutation_tests__basic__select_by_pk.snap

@@ -0,0 +1,13 @@
+---
+source: crates/ndc-postgres/tests/mutation_tests.rs
+expression: result
+---
+[
+  {
+    "rows": [
+      {
+        "Title": "Garage Inc. (Disc 1)"
+      }
+    ]
+  }
+]

crates/other-db-tests/src/aurora/common.rs

@@ -16,7 +16,7 @@ pub async fn create_router() -> axum::Router {
 
     // work out where the deployment configs live
     let test_deployment_file =
-        tests_common::deployment::get_deployment_file(CHINOOK_DEPLOYMENT_PATH);
+        tests_common::deployment::helpers::get_path_from_project_root(CHINOOK_DEPLOYMENT_PATH);
 
     // initialise server state with the static configuration.
     let state = ndc_sdk::default_main::init_server_state::<connector::Postgres>(

crates/tests-common/Cargo.toml

@@ -17,3 +17,6 @@ tracing = "0.1.37"
 axum = "0.6.19"
 axum-test-helper = "0.3.0"
 reqwest = "0.11.20"
+tokio-postgres = "0.7.10"
+sqlx = { version = "0.7.1", features = [ "json", "postgres", "runtime-tokio-rustls" ] }
+uuid = {version = "1.4.1", features = [ "v4", "fast-rng", "macro-diagnostics" ]}

crates/tests-common/src/deployment/configuration.rs

@@ -0,0 +1,44 @@
+//! Deployment configuration functions used across test cases.
+//! Use via helpers in `mod.rs` rather than directly.
+//!
+use super::helpers::get_path_from_project_root;
+use serde_json::Value;
+use std::fs;
+
+/// Load deployment at `main_deployment_path`
+/// replace url with `new_postgres_url`
+/// save at `new_deployment_path`
+pub fn copy_deployment_with_new_postgres_url(
+    main_deployment_path: &str,
+    new_postgres_url: &str,
+    new_deployment_path: &str,
+) {
+    let full_path = get_path_from_project_root(main_deployment_path);
+
+    // load and decode deployment
+    let deployment: Value = serde_json::from_str(&fs::read_to_string(full_path).unwrap()).unwrap();
+
+    let new_json = match deployment {
+        Value::Object(mut map) => {
+            map.insert(
+                "postgres_database_url".to_string(),
+                Value::String(new_postgres_url.to_string()),
+            );
+            Value::Object(map)
+        }
+        other => other,
+    };
+
+    let new_absolute_deployment_path = get_path_from_project_root(new_deployment_path);
+
+    let new_deployment = new_json.to_string();
+
+    fs::write(new_absolute_deployment_path, new_deployment).unwrap()
+}
+
+/// Erase test deployment file created at `deployment_path`
+pub fn delete_deployment(deployment_path: &str) {
+    let absolute_path = get_path_from_project_root(deployment_path);
+
+    fs::remove_file(absolute_path).unwrap()
+}