Return user-readable drift summary in migrate dev

Makefile

@@ -87,7 +87,7 @@ start-mysql_8:
 
 dev-mysql8: start-mysql_8
 	echo 'mysql8' > current_connector
-	cp $(CONFIG_PATH)/mysql58 $(CONFIG_FILE)
+	cp $(CONFIG_PATH)/mysql8 $(CONFIG_FILE)
 
 start-mysql_mariadb:
 	docker-compose -f docker-compose.yml up -d --remove-orphans mariadb-10-0

libs/datamodel/core/src/ast/mod.rs

@@ -52,7 +52,7 @@ pub(crate) use renderer::Renderer;
 #[derive(Debug, Clone, PartialEq)]
 pub struct SchemaAst {
     /// All models, enums, datasources, generators or type aliases
-    pub tops: Vec<Top>,
+    pub(crate) tops: Vec<Top>,
 }
 
 impl SchemaAst {

migration-engine/connectors/migration-connector/src/lib.rs

@@ -83,6 +83,9 @@ pub trait DatabaseMigrationMarker: Debug + Send + Sync {
 
     /// Is the migration empty?
     fn is_empty(&self) -> bool;
+
+    /// Render a human-readable summary of the migrations content, for drift diagnostics.
+    fn summary(&self) -> String;
 }
 
 /// Shorthand for a [Result](https://doc.rust-lang.org/std/result/enum.Result.html) where the error

migration-engine/connectors/mongodb-migration-connector/src/mongodb_migration.rs

@@ -11,6 +11,22 @@ impl DatabaseMigrationMarker for MongoDbMigration {
     fn is_empty(&self) -> bool {
         self.steps.is_empty()
     }
+
+    fn summary(&self) -> String {
+        let mut out = String::with_capacity(self.steps.len() * 10);
+
+        for step in &self.steps {
+            match step {
+                MongoDbMigrationStep::CreateCollection(collection) => {
+                    out.push_str("- Added collection `");
+                    out.push_str(collection);
+                    out.push_str("`\n");
+                }
+            }
+        }
+
+        out
+    }
 }
 
 #[derive(Debug)]

migration-engine/connectors/sql-migration-connector/src/sql_migration.rs

@@ -159,7 +159,11 @@ impl SqlMigration {
                     DriftType::RemovedTable => out.push_str("\n[-] Removed tables\n"),
                     DriftType::RemovedUdt => out.push_str("\n[-] Removed UDTs\n"),
                     DriftType::RemovedView => out.push_str("\n[-] Removed views\n"),
-                    DriftType::RedefinedTable => out.push_str("\n[*] Redefined tables\n"),
+                    DriftType::RedefinedTable => {
+                        out.push_str("\n[*] Redefined table `");
+                        out.push_str(item_name);
+                        out.push_str("`\n")
+                    }
                     DriftType::ChangedEnum => {
                         out.push_str("\n[*] Changed the `");
                         out.push_str(item_name);
@@ -373,6 +377,10 @@ impl DatabaseMigrationMarker for SqlMigration {
     fn is_empty(&self) -> bool {
         self.steps.is_empty()
     }
+
+    fn summary(&self) -> String {
+        self.drift_summary()
+    }
 }
 
 // The order of the variants matters for sorting. The steps are sorted _first_

migration-engine/core/src/api.rs

@@ -54,7 +54,7 @@ pub trait GenericApi: Send + Sync + 'static {
     ) -> CoreResult<MarkMigrationRolledBackOutput>;
 
     /// Prepare to create a migration.
-    async fn plan_migration(&self, input: &PlanMigrationInput) -> CoreResult<PlanMigrationOutput>;
+    async fn plan_migration(&self) -> CoreResult<()>;
 
     /// Reset a database to an empty state (no data, no schema).
     async fn reset(&self) -> CoreResult<()>;
@@ -99,7 +99,7 @@ impl<C: MigrationConnector> GenericApi for C {
         &self,
         input: &DiagnoseMigrationHistoryInput,
     ) -> CoreResult<DiagnoseMigrationHistoryOutput> {
-        DiagnoseMigrationHistoryCommand::execute(input, self)
+        diagnose_migration_history(input, self)
             .instrument(tracing::info_span!("DiagnoseMigrationHistory"))
             .await
     }
@@ -149,10 +149,8 @@ impl<C: MigrationConnector> GenericApi for C {
             .await
     }
 
-    async fn plan_migration(&self, input: &PlanMigrationInput) -> CoreResult<PlanMigrationOutput> {
-        PlanMigrationCommand::execute(input, self)
-            .instrument(tracing::info_span!("PlanMigration"))
-            .await
+    async fn plan_migration(&self) -> CoreResult<()> {
+        unreachable!("PlanMigration command")
     }
 
     async fn reset(&self) -> CoreResult<()> {

migration-engine/core/src/api/rpc.rs

@@ -126,7 +126,7 @@ impl RpcApi {
             }
             RpcCommand::MarkMigrationApplied => render(executor.mark_migration_applied(&params.parse()?).await?),
             RpcCommand::MarkMigrationRolledBack => render(executor.mark_migration_rolled_back(&params.parse()?).await?),
-            RpcCommand::PlanMigration => render(executor.plan_migration(&params.parse()?).await?),
+            RpcCommand::PlanMigration => render(executor.plan_migration().await?),
             RpcCommand::Reset => render(executor.reset().await?),
             RpcCommand::SchemaPush => render(executor.schema_push(&params.parse()?).await?),
         })

migration-engine/core/src/commands.rs

@@ -10,23 +10,21 @@ mod evaluate_data_loss;
 mod list_migration_directories;
 mod mark_migration_applied;
 mod mark_migration_rolled_back;
-mod plan_migration;
 mod schema_push;
 
 pub use apply_migrations::{ApplyMigrationsCommand, ApplyMigrationsInput, ApplyMigrationsOutput};
 pub use command::MigrationCommand;
 pub use create_migration::{CreateMigrationCommand, CreateMigrationInput, CreateMigrationOutput};
-pub(crate) use dev_diagnostic::dev_diagnostic;
 pub use dev_diagnostic::{DevAction, DevDiagnosticInput, DevDiagnosticOutput};
 pub use diagnose_migration_history::{
-    DiagnoseMigrationHistoryCommand, DiagnoseMigrationHistoryInput, DiagnoseMigrationHistoryOutput, DriftDiagnostic,
-    HistoryDiagnostic,
+    DiagnoseMigrationHistoryInput, DiagnoseMigrationHistoryOutput, DriftDiagnostic, HistoryDiagnostic,
 };
 pub use evaluate_data_loss::*;
 pub use list_migration_directories::*;
 pub use mark_migration_applied::{MarkMigrationAppliedCommand, MarkMigrationAppliedInput, MarkMigrationAppliedOutput};
 pub use mark_migration_rolled_back::{MarkMigrationRolledBackInput, MarkMigrationRolledBackOutput};
-pub use plan_migration::{PlanMigrationCommand, PlanMigrationInput, PlanMigrationOutput};
 pub use schema_push::{SchemaPushCommand, SchemaPushInput, SchemaPushOutput};
 
+pub(crate) use dev_diagnostic::dev_diagnostic;
+pub(crate) use diagnose_migration_history::diagnose_migration_history;
 pub(crate) use mark_migration_rolled_back::mark_migration_rolled_back;

migration-engine/core/src/commands/dev_diagnostic.rs

@@ -1,6 +1,6 @@
 use super::{
-    DiagnoseMigrationHistoryCommand, DiagnoseMigrationHistoryInput, DiagnoseMigrationHistoryOutput, DriftDiagnostic,
-    HistoryDiagnostic, MigrationCommand,
+    diagnose_migration_history, DiagnoseMigrationHistoryInput, DiagnoseMigrationHistoryOutput, DriftDiagnostic,
+    HistoryDiagnostic,
 };
 use migration_connector::{ConnectorResult, MigrationConnector};
 use serde::{Deserialize, Serialize};
@@ -33,8 +33,7 @@ pub(crate) async fn dev_diagnostic<C: MigrationConnector>(
         opt_in_to_shadow_database: true,
     };
 
-    let diagnose_migration_history_output =
-        DiagnoseMigrationHistoryCommand::execute(&diagnose_input, connector).await?;
+    let diagnose_migration_history_output = diagnose_migration_history(&diagnose_input, connector).await?;
 
     check_for_broken_migrations(&diagnose_migration_history_output)?;
 
@@ -75,11 +74,11 @@ fn check_for_reset_conditions(output: &DiagnoseMigrationHistoryOutput) -> Option
         ))
     }
 
-    if let Some(DriftDiagnostic::DriftDetected { rollback }) = &output.drift {
-        tracing::info!(rollback = rollback.as_str(), "DriftDetected diagnostic");
-
-        reset_reasons
-            .push("Drift detected: Your database schema is not in sync with your migration history.".to_owned())
+    if let Some(DriftDiagnostic::DriftDetected { summary }) = &output.drift {
+        let mut reason =
+            "Drift detected: Your database schema is not in sync with your migration history.\n".to_owned();
+        reason.push_str(summary);
+        reset_reasons.push(reason);
     }
 
     match &output.history {