Unmount and remount connects to the same component data (#28828)

This PR implements some of the desired component unmount + remount behavior.
* Adds a new `ComponentState` to the metadata, unmounting instead of deleting the component when you push a configuration without an existing component.
* Remounts components at the same path to the same data.
* Adds an application-level test that unmounts + remounts by pushing a `mounted` project, then an `empty` project, then the `mounted` project again.

This does not make the data read-only while unmounted, will follow up about that.

GitOrigin-RevId: 9fe3753af05308066a0cb385d6357d3bb1a828a1

crates/application/src/tests/components.rs

@@ -1,4 +1,5 @@
 use common::{
+    bootstrap_model::components::ComponentState,
     components::{
         CanonicalizedComponentFunctionPath,
         ComponentId,
@@ -12,6 +13,7 @@ use common::{
     RequestId,
 };
 use database::{
+    BootstrapComponentsModel,
     TableModel,
     UserFacingModel,
 };
@@ -44,12 +46,21 @@ async fn run_function(
     application: &Application<TestRuntime>,
     udf_path: CanonicalizedUdfPath,
     args: Vec<JsonValue>,
+) -> anyhow::Result<Result<FunctionReturn, FunctionError>> {
+    run_component_function(application, udf_path, args, ComponentPath::root()).await
+}
+
+async fn run_component_function(
+    application: &Application<TestRuntime>,
+    udf_path: CanonicalizedUdfPath,
+    args: Vec<JsonValue>,
+    component: ComponentPath,
 ) -> anyhow::Result<Result<FunctionReturn, FunctionError>> {
     application
         .any_udf(
             RequestId::new(),
             CanonicalizedComponentFunctionPath {
-                component: ComponentPath::root(),
+                component,
                 udf_path,
             },
             args,
@@ -246,3 +257,76 @@ async fn test_delete_tables_in_component(rt: TestRuntime) -> anyhow::Result<()>
     assert!(!table_model.table_exists(table_namespace, &table_name));
     Ok(())
 }
+
+#[convex_macro::test_runtime]
+async fn test_unmount_and_remount_component(rt: TestRuntime) -> anyhow::Result<()> {
+    let application = Application::new_for_tests(&rt).await?;
+    application.load_component_tests_modules("mounted").await?;
+    let component_path = ComponentPath::deserialize(Some("component"))?;
+    run_component_function(
+        &application,
+        "messages:insertMessage".parse()?,
+        vec![assert_obj!("channel" => "sports", "text" => "the celtics won!").into()],
+        component_path.clone(),
+    )
+    .await??;
+
+    // Unmount component
+    application.load_component_tests_modules("empty").await?;
+
+    let mut tx = application.begin(Identity::system()).await?;
+    let mut components_model = BootstrapComponentsModel::new(&mut tx);
+    let (_, component_id) = components_model
+        .component_path_to_ids(component_path.clone())
+        .await?;
+    let component = components_model
+        .load_component(component_id)
+        .await?
+        .unwrap();
+    assert!(matches!(component.state, ComponentState::Unmounted));
+
+    // Data should still exist in unmounted component tables
+    let mut table_model = TableModel::new(&mut tx);
+    let count = table_model
+        .count(component_id.into(), &"messages".parse()?)
+        .await?;
+    assert_eq!(count, 1);
+
+    // Calling component function after the component is unmounted should fail
+    let result = run_component_function(
+        &application,
+        "messages:listMessages".parse()?,
+        vec![assert_obj!().into()],
+        ComponentPath::deserialize(Some("component"))?,
+    )
+    .await?;
+    assert!(result.is_err());
+
+    // Remount the component
+    application.load_component_tests_modules("mounted").await?;
+
+    let mut tx = application.begin(Identity::system()).await?;
+    let mut components_model = BootstrapComponentsModel::new(&mut tx);
+    let component = components_model
+        .load_component(component_id)
+        .await?
+        .unwrap();
+    assert!(matches!(component.state, ComponentState::Active));
+
+    // Data should still exist in remounted component tables
+    let mut table_model = TableModel::new(&mut tx);
+    let count = table_model
+        .count(component_id.into(), &"messages".parse()?)
+        .await?;
+    assert_eq!(count, 1);
+
+    // Calling functions from the remounted component should work
+    run_component_function(
+        &application,
+        "messages:listMessages".parse()?,
+        vec![assert_obj!().into()],
+        ComponentPath::deserialize(Some("component"))?,
+    )
+    .await??;
+    Ok(())
+}

crates/common/src/bootstrap_model/components/mod.rs

@@ -24,6 +24,17 @@ use crate::components::{
 pub struct ComponentMetadata {
     pub definition_id: DeveloperDocumentId,
     pub component_type: ComponentType,
+    pub state: ComponentState,
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+#[cfg_attr(any(test, feature = "testing"), derive(proptest_derive::Arbitrary))]
+pub enum ComponentState {
+    /// The component is mounted and can be used.
+    Active,
+    /// The component is unmounted. Component functions are not available, and
+    /// tables in the component are read-only.
+    Unmounted,
 }
 
 impl ComponentMetadata {
@@ -59,6 +70,7 @@ struct SerializedComponentMetadata {
     pub parent: Option<String>,
     pub name: Option<String>,
     pub args: Option<Vec<(String, SerializedResource)>>,
+    pub state: Option<String>,
 }
 
 impl TryFrom<ComponentMetadata> for SerializedComponentMetadata {
@@ -77,11 +89,16 @@ impl TryFrom<ComponentMetadata> for SerializedComponentMetadata {
                 ),
             ),
         };
+        let state = match m.state {
+            ComponentState::Active => "active",
+            ComponentState::Unmounted => "unmounted",
+        };
         Ok(Self {
             definition_id: m.definition_id.to_string(),
             parent,
             name,
             args,
+            state: Some(state.to_string()),
         })
     }
 }
@@ -102,9 +119,15 @@ impl TryFrom<SerializedComponentMetadata> for ComponentMetadata {
             },
             _ => anyhow::bail!("Invalid component type"),
         };
+        let state = match m.state.as_deref() {
+            None | Some("active") => ComponentState::Active,
+            Some("unmounted") => ComponentState::Unmounted,
+            Some(invalid_state) => anyhow::bail!("Invalid component state: {invalid_state}"),
+        };
         Ok(Self {
             definition_id: m.definition_id.parse()?,
             component_type,
+            state,
         })
     }
 }

crates/database/src/bootstrap_model/components/mod.rs

@@ -416,6 +416,7 @@ mod tests {
                 ComponentInstantiation,
             },
             ComponentMetadata,
+            ComponentState,
             ComponentType,
         },
         components::{
@@ -481,6 +482,7 @@ mod tests {
                 ComponentMetadata {
                     definition_id: root_definition_id.into(),
                     component_type: ComponentType::App,
+                    state: ComponentState::Active,
                 }
                 .try_into()?,
             )
@@ -495,6 +497,7 @@ mod tests {
                         name: "subcomponent_child".parse()?,
                         args: Default::default(),
                     },
+                    state: ComponentState::Active,
                 }
                 .try_into()?,
             )

crates/isolate/build.rs

@@ -30,7 +30,7 @@ const COMPONENT_TESTS_DIR: &str = "../../npm-packages/component-tests";
 const COMPONENT_TESTS_CHILD_DIR_EXCEPTIONS: [&str; 3] = [".rush", "node_modules", "projects"];
 /// Directory where test projects that use components live.
 const COMPONENT_TESTS_PROJECTS_DIR: &str = "../../npm-packages/component-tests/projects";
-const COMPONENT_TESTS_PROJECTS: [&str; 2] = ["basic", "with-schema"];
+const COMPONENT_TESTS_PROJECTS: [&str; 4] = ["basic", "with-schema", "mounted", "empty"];
 /// Components in `component-tests` directory that are used in projects.
 const COMPONENTS: [&str; 3] = ["component", "envVars", "errors"];
 

crates/model/src/components/config.rs

@@ -6,6 +6,7 @@ use common::{
         components::{
             definition::ComponentDefinitionMetadata,
             ComponentMetadata,
+            ComponentState,
             ComponentType,
         },
         schema::SchemaState,
@@ -402,8 +403,8 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
         let mut stack = vec![(ComponentPath::root(), None, existing_root, Some(app))];
         let mut diffs = BTreeMap::new();
         while let Some((path, parent_and_name, existing_node, new_node)) = stack.pop() {
-            let new_metadata = match new_node {
-                Some(new_node) => {
+            let new_metadata = new_node
+                .map(|new_node| {
                     let definition_id = *definition_id_by_path
                         .get(&new_node.definition_path)
                         .context("Missing definition ID for component")?;
@@ -418,13 +419,13 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
                             args: new_node.args.clone(),
                         },
                     };
-                    Some(ComponentMetadata {
+                    Ok(ComponentMetadata {
                         definition_id,
                         component_type,
+                        state: ComponentState::Active,
                     })
-                },
-                None => None,
-            };
+                })
+                .transpose()?;
 
             // Diff the node itself.
             let (internal_id, diff) = match (existing_node, new_metadata) {
@@ -452,8 +453,8 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
                     )
                     .await?
                 },
-                // Delete an existing node.
-                (Some(existing_node), None) => self.delete_component(existing_node).await?,
+                // Unmount an existing node.
+                (Some(existing_node), None) => self.unmount_component(existing_node).await?,
                 (None, None) => anyhow::bail!("Unexpected None/None in stack"),
             };
             diffs.insert(path.clone(), diff);
@@ -613,7 +614,7 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
         ))
     }
 
-    async fn delete_component(
+    async fn unmount_component(
         &mut self,
         existing: &ParsedDocument<ComponentMetadata>,
     ) -> anyhow::Result<(DeveloperDocumentId, ComponentDiff)> {
@@ -622,9 +623,10 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
         } else {
             ComponentId::Child(existing.id().into())
         };
-        // TODO: Delete the component's system tables.
+        let mut unmounted_metadata = existing.clone().into_value();
+        unmounted_metadata.state = ComponentState::Unmounted;
         SystemMetadataModel::new_global(self.tx)
-            .delete(existing.id())
+            .replace(existing.id(), unmounted_metadata.try_into()?)
             .await?;
         let module_diff = ModuleModel::new(self.tx)
             .apply(component_id, vec![], None, BTreeMap::new())
@@ -638,7 +640,7 @@ impl<'a, RT: Runtime> ComponentConfigModel<'a, RT> {
         Ok((
             existing.id().into(),
             ComponentDiff {
-                diff_type: ComponentDiffType::Delete,
+                diff_type: ComponentDiffType::Unmount,
                 module_diff,
                 udf_config_diff: None,
                 cron_diff,
@@ -703,7 +705,7 @@ struct TreeDiffChild<'a> {
 pub enum ComponentDiffType {
     Create,
     Modify,
-    Delete,
+    Unmount,
 }
 
 pub struct ComponentDiff {
@@ -718,7 +720,7 @@ pub struct ComponentDiff {
 pub enum SerializedComponentDiffType {
     Create,
     Modify,
-    Delete,
+    Unmount,
 }
 
 #[derive(Serialize)]
@@ -737,7 +739,7 @@ impl TryFrom<ComponentDiffType> for SerializedComponentDiffType {
         Ok(match value {
             ComponentDiffType::Create => Self::Create,
             ComponentDiffType::Modify => Self::Modify,
-            ComponentDiffType::Delete => Self::Delete,
+            ComponentDiffType::Unmount => Self::Unmount,
         })
     }
 }

npm-packages/component-tests/projects/empty/.gitignore

@@ -0,0 +1,2 @@
+
+.env.local