Restore proper configure options defaults, and add a test (#93)

### What

By mistake, the confgure options had gotten empty defaults. The proper
defaults have now been restored.

### How

* A manual Default trait instance
* A test that checks that a 'vanilla' deployment (i.e., the one
generated from only a connectionUri) doesn't change.

crates/connectors/ndc-postgres/src/configuration/version1.rs

@@ -32,7 +32,7 @@ pub struct RawConfiguration {
 }
 
 /// Options which only influence how the configuration server updates the configuration
-#[derive(Debug, Default, Deserialize, Serialize, JsonSchema)]
+#[derive(Debug, Deserialize, Serialize, JsonSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct ConfigureOptions {
     /// Schemas which are excluded from introspection. The default setting will exclude the
@@ -44,6 +44,15 @@ pub struct ConfigureOptions {
     pub comparison_operator_mapping: Vec<ComparisonOperatorMapping>,
 }
 
+impl Default for ConfigureOptions {
+    fn default() -> ConfigureOptions {
+        ConfigureOptions {
+            excluded_schemas: default_excluded_schemas(),
+            comparison_operator_mapping: default_comparison_operator_mapping(),
+        }
+    }
+}
+
 /// Define the names that comparison operators will be exposed as by the automatic introspection.
 #[derive(Debug, Clone, Deserialize, Serialize, JsonSchema)]
 #[serde(rename_all = "camelCase")]

crates/connectors/ndc-postgres/tests/configuration_tests.rs

@@ -1,7 +1,3 @@
-//! Tests that configuration generation has not changed.
-//!
-//! If you have changed it intentionally, run `just generate-chinook-configuration`.
-
 pub mod common;
 
 use std::fs;
@@ -16,7 +12,13 @@ use tests_common::schemas::check_value_conforms_to_schema;
 const CONFIGURATION_QUERY: &str = include_str!("../src/configuration.sql");
 
 #[tokio::test]
-async fn test_configure() {
+// Tests that configuration generation has not changed.
+//
+// This test does not use insta snapshots because it checks the deployment file that is shared with
+// other tests.
+//
+// If you have changed it intentionally, run `just generate-chinook-configuration`.
+async fn test_configure_is_idempotent() {
     let expected_value = read_configuration();
 
     let mut args: configuration::RawConfiguration = serde_json::from_value(expected_value.clone())
@@ -34,6 +36,22 @@ async fn test_configure() {
     assert_eq!(expected_value, actual_value);
 }
 
+#[tokio::test]
+async fn test_configure_initial_configuration_is_unchanged() {
+    let args = configuration::RawConfiguration {
+        connection_uri: configuration::ConnectionUri::Uri(configuration::ResolvedSecret(
+            common::POSTGRESQL_CONNECTION_STRING.to_string(),
+        )),
+        ..configuration::RawConfiguration::empty()
+    };
+
+    let default_configuration = configuration::configure(args, CONFIGURATION_QUERY)
+        .await
+        .expect("configuration::configure");
+
+    insta::assert_json_snapshot!(default_configuration);
+}
+
 #[test]
 fn configuration_conforms_to_the_schema() {
     check_value_conforms_to_schema::<configuration::RawConfiguration>(read_configuration());