Add event node support

codama-attributes/src/attributes.rs

@@ -72,6 +72,8 @@ impl<'a> Attributes<'a> {
         self.has_codama_derive("CodamaAccount")
             || self.has_codama_derive("CodamaAccounts")
             || self.has_codama_derive("CodamaErrors")
+            || self.has_codama_derive("CodamaEvent")
+            || self.has_codama_derive("CodamaEvents")
             || self.has_codama_derive("CodamaInstruction")
             || self.has_codama_derive("CodamaInstructions")
             || self.has_codama_derive("CodamaPda")

codama-attributes/src/codama_directives/program_directive.rs

@@ -75,6 +75,13 @@ impl ProgramDirective {
                 ..ProgramNode::default()
             }
             .into(),
+            Node::Event(event) => ProgramNode {
+                name: self.name.clone(),
+                public_key: self.address.clone(),
+                events: vec![event],
+                ..ProgramNode::default()
+            }
+            .into(),
             other => other,
         }
     }

codama-korok-visitors/src/combine_modules_visitor.rs

@@ -141,6 +141,10 @@ fn get_scraps_root_node(nodes: Vec<Node>) -> Option<RootNode> {
                 add_or_replace_node_with_name(&mut root.program.pdas, node);
                 has_scraps = true
             }
+            Node::Event(node) => {
+                add_or_replace_node_with_name(&mut root.program.events, node);
+                has_scraps = true
+            }
             _ => (),
         }
     }
@@ -210,8 +214,9 @@ fn merge_program_nodes(this: &mut ProgramNode, that: ProgramNode) {
     merge_nodes_with_name(&mut this.accounts, that.accounts);
     merge_nodes_with_name(&mut this.instructions, that.instructions);
     merge_nodes_with_name(&mut this.defined_types, that.defined_types);
-    merge_nodes_with_name(&mut this.errors, that.errors);
     merge_nodes_with_name(&mut this.pdas, that.pdas);
+    merge_nodes_with_name(&mut this.events, that.events);
+    merge_nodes_with_name(&mut this.errors, that.errors);
 }
 
 fn merge_nodes_with_name<T>(nodes: &mut Vec<T>, new_nodes: Vec<T>)

codama-korok-visitors/src/lib.rs

@@ -10,6 +10,7 @@ mod set_accounts_visitor;
 mod set_default_values_visitor;
 mod set_defined_types_visitor;
 mod set_errors_visitor;
+mod set_events_visitor;
 mod set_instructions_visitors;
 mod set_pdas_visitor;
 mod set_program_metadata_visitor;
@@ -29,6 +30,7 @@ pub use set_accounts_visitor::*;
 pub use set_default_values_visitor::*;
 pub use set_defined_types_visitor::*;
 pub use set_errors_visitor::*;
+pub use set_events_visitor::*;
 pub use set_instructions_visitors::*;
 pub use set_pdas_visitor::*;
 pub use set_program_metadata_visitor::*;

codama-korok-visitors/src/set_events_visitor.rs

@@ -0,0 +1,213 @@
+use crate::{CombineTypesVisitor, KorokVisitor};
+use codama_attributes::{
+    DiscriminatorDirective, EnumDiscriminatorDirective, ProgramDirective, TryFromFilter,
+};
+use codama_errors::CodamaResult;
+use codama_nodes::{
+    CamelCaseString, DefaultValueStrategy, EnumVariantTypeNode, EventNode, FieldDiscriminatorNode,
+    NestedTypeNode, NestedTypeNodeTrait, Node, NumberValueNode, ProgramNode, StructFieldTypeNode,
+    StructTypeNode,
+};
+use codama_syn_helpers::extensions::*;
+
+pub struct SetEventsVisitor {
+    combine_types: CombineTypesVisitor,
+    enum_name: String,
+    enum_discriminator: EnumDiscriminatorDirective,
+    enum_current_discriminator: usize,
+}
+
+impl Default for SetEventsVisitor {
+    fn default() -> Self {
+        Self {
+            combine_types: CombineTypesVisitor::strict(),
+            enum_name: "".to_string(),
+            enum_discriminator: EnumDiscriminatorDirective::default(),
+            enum_current_discriminator: 0,
+        }
+    }
+}
+
+impl SetEventsVisitor {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl KorokVisitor for SetEventsVisitor {
+    fn visit_struct(&mut self, korok: &mut codama_koroks::StructKorok) -> CodamaResult<()> {
+        // No overrides.
+        if korok.node.is_some() {
+            return Ok(());
+        };
+
+        // Ensure the struct has the `CodamaEvent` attribute.
+        if !korok.attributes.has_codama_derive("CodamaEvent") {
+            return Ok(());
+        };
+
+        // Create a `DefinedTypeNode` from the struct, if it doesn't already exist.
+        self.combine_types.visit_struct(korok)?;
+
+        // Transform the defined type into an event node.
+        let (name, data) = parse_struct(korok)?;
+
+        let event = EventNode {
+            discriminators: DiscriminatorDirective::nodes(&korok.attributes),
+            ..EventNode::new(name, data)
+        };
+
+        korok.node = Some(ProgramDirective::apply(&korok.attributes, event.into()));
+
+        Ok(())
+    }
+
+    fn visit_enum(&mut self, korok: &mut codama_koroks::EnumKorok) -> CodamaResult<()> {
+        // No overrides.
+        if korok.node.is_some() {
+            return Ok(());
+        };
+
+        // Ensure the enum has the `CodamaEvents` attribute.
+        if !korok.attributes.has_codama_derive("CodamaEvents") {
+            return Ok(());
+        };
+
+        // Create a `DefinedTypeNode` from the enum.
+        self.combine_types.visit_enum(korok)?;
+
+        // Get enum discriminator info.
+        let enum_discriminator = korok
+            .attributes
+            .get_last(EnumDiscriminatorDirective::filter)
+            .cloned()
+            .unwrap_or_else(|| EnumDiscriminatorDirective::from(&korok.node));
+
+        // Transform each variant into an `EventNode`.
+        self.enum_name = korok.ast.ident.to_string();
+        self.enum_discriminator = enum_discriminator;
+        self.enum_current_discriminator = 0;
+
+        self.visit_children(korok)?;
+
+        // Gather all events in the variants.
+        let events = korok
+            .variants
+            .iter()
+            .filter_map(|variant| match &variant.node {
+                Some(Node::Event(event)) => Some(event.clone()),
+                _ => None,
+            })
+            .collect::<Vec<_>>();
+
+        let node: Node = ProgramNode {
+            events,
+            ..ProgramNode::default()
+        }
+        .into();
+
+        korok.node = Some(ProgramDirective::apply(&korok.attributes, node));
+
+        Ok(())
+    }
+
+    fn visit_enum_variant(
+        &mut self,
+        korok: &mut codama_koroks::EnumVariantKorok,
+    ) -> CodamaResult<()> {
+        // Update current discriminator.
+        let current_discriminator = match &korok.ast.discriminant {
+            Some((_, expr)) => expr.as_unsigned_integer()?,
+            _ => self.enum_current_discriminator,
+        };
+
+        self.enum_current_discriminator = current_discriminator + 1;
+
+        // Skip variants with #[codama(skip)] directive.
+        if korok.attributes.has_codama_attribute("skip") {
+            return Ok(());
+        };
+
+        let discriminator = StructFieldTypeNode {
+            default_value_strategy: Some(DefaultValueStrategy::Omitted),
+            default_value: Some(NumberValueNode::new(current_discriminator as u64).into()),
+            ..StructFieldTypeNode::from(&self.enum_discriminator)
+        };
+
+        let discriminator_name = discriminator.name.clone();
+
+        let (name, data) = parse_enum_variant(korok, &self.enum_name)?;
+
+        let data = data.map_nested_type_node(|node| {
+            let mut fields = node.fields;
+
+            fields.insert(0, discriminator);
+
+            StructTypeNode { fields }
+        });
+
+        let mut discriminators = DiscriminatorDirective::nodes(&korok.attributes);
+
+        discriminators.insert(0, FieldDiscriminatorNode::new(discriminator_name, 0).into());
+
+        let event = EventNode {
+            discriminators,
+            ..EventNode::new(name, data)
+        };
+
+        korok.node = Some(event.into());
+
+        Ok(())
+    }
+}
+
+fn parse_struct(
+    korok: &codama_koroks::StructKorok,
+) -> CodamaResult<(CamelCaseString, NestedTypeNode<StructTypeNode>)> {
+    // Ensure we have a `DefinedTypeNode` to work with.
+    if let Some(Node::DefinedType(node)) = &korok.node {
+        // Ensure the data type is a struct.
+        if let Ok(data) = NestedTypeNode::<StructTypeNode>::try_from(node.r#type.clone()) {
+            return Ok((node.name.clone(), data));
+        };
+    };
+
+    // Handle error.
+    let message = format!(
+        "The \"{}\" struct could not be used as an Event because its type is not a `NestedTypeNode<StructTypeNode>`.",
+        korok.ast.ident,
+    );
+
+    Err(korok.ast.error(message).into())
+}
+
+fn parse_enum_variant(
+    korok: &codama_koroks::EnumVariantKorok,
+    enum_name: &str,
+) -> CodamaResult<(CamelCaseString, NestedTypeNode<StructTypeNode>)> {
+    // Ensure we have a `Node`.
+    if let Some(node) = &korok.node {
+        // Ensure we have a `EnumVariantTypeNode`.
+        if let Ok(node) = EnumVariantTypeNode::try_from(node.clone()) {
+            match node {
+                // Ensure we have a non-nested `StructTypeNode`.
+                EnumVariantTypeNode::Struct(node) => {
+                    return Ok((node.name, node.r#struct));
+                }
+                // Or an empty variant.
+                EnumVariantTypeNode::Empty(node) => {
+                    return Ok((node.name, StructTypeNode::new(vec![]).into()))
+                }
+                _ => {}
+            }
+        };
+    };
+
+    // Handle error.
+    let message = format!(
+        "The \"{}\" variant of the \"{enum_name}\" enum could not be used as an Event because we cannot get a `StructTypeNode` for it. This is likely because it is not using named fields.",
+        korok.ast.ident
+    );
+
+    Err(korok.ast.error(message).into())
+}

codama-korok-visitors/tests/combine_modules_visitor/event_node.rs

@@ -0,0 +1,104 @@
+use super::utils::{combine_modules, CombineModulesInput};
+use codama_nodes::{EventNode, ProgramNode, RootNode, StructTypeNode};
+
+#[test]
+fn it_merges_events_into_root_nodes() {
+    let transfer = EventNode::new("transfer", StructTypeNode::default());
+    let burn = EventNode::new("burn", StructTypeNode::default());
+    assert_eq!(
+        combine_modules(
+            CombineModulesInput::new()
+                .add_node(transfer.clone())
+                .add_node(burn.clone())
+        ),
+        Some(RootNode::new(ProgramNode::default().add_event(transfer).add_event(burn)).into())
+    );
+}
+
+#[test]
+fn it_merges_events_inside_programs_into_root_nodes() {
+    let event_a = EventNode::new("foo", StructTypeNode::default());
+    let event_b = EventNode::new("bar", StructTypeNode::default());
+    let program_a = ProgramNode::default().add_event(event_a.clone());
+    let program_b = ProgramNode::default().add_event(event_b.clone());
+    assert_eq!(
+        combine_modules(
+            CombineModulesInput::new()
+                .add_node(program_a)
+                .add_node(program_b)
+        ),
+        Some(RootNode::new(ProgramNode::default().add_event(event_a).add_event(event_b)).into())
+    );
+}
+
+#[test]
+fn it_deduplicates_events_with_identical_names_by_using_the_last_one() {
+    let first = EventNode::new("duplicated", StructTypeNode::default());
+    let second = EventNode::new(
+        "duplicated",
+        StructTypeNode::new(vec![codama_nodes::StructFieldTypeNode::new(
+            "amount",
+            codama_nodes::NumberTypeNode::le(codama_nodes::NumberFormat::U64),
+        )]),
+    );
+    let third = EventNode::new(
+        "duplicated",
+        StructTypeNode::new(vec![codama_nodes::StructFieldTypeNode::new(
+            "value",
+            codama_nodes::NumberTypeNode::le(codama_nodes::NumberFormat::U32),
+        )]),
+    );
+    assert_eq!(
+        combine_modules(
+            CombineModulesInput::new()
+                .add_node(first)
+                .add_node(second)
+                .add_node(third.clone())
+        ),
+        Some(RootNode::new(ProgramNode::default().add_event(third)).into())
+    );
+}
+
+#[test]
+fn it_deduplicates_events_with_identical_names_inside_programs() {
+    let first = EventNode::new("duplicated", StructTypeNode::default());
+    let second = EventNode::new(
+        "duplicated",
+        StructTypeNode::new(vec![codama_nodes::StructFieldTypeNode::new(
+            "amount",
+            codama_nodes::NumberTypeNode::le(codama_nodes::NumberFormat::U64),
+        )]),
+    );
+    let program_a = ProgramNode::default().add_event(first);
+    let program_b = ProgramNode::default().add_event(second.clone());
+    assert_eq!(
+        combine_modules(
+            CombineModulesInput::new()
+                .add_node(program_a)
+                .add_node(program_b)
+        ),
+        Some(RootNode::new(ProgramNode::default().add_event(second)).into())
+    );
+}
+
+#[test]
+fn it_deduplicates_events_with_identical_names_with_an_initial_program_node() {
+    let first = EventNode::new("duplicated", StructTypeNode::default());
+    let second = EventNode::new(
+        "duplicated",
+        StructTypeNode::new(vec![codama_nodes::StructFieldTypeNode::new(
+            "amount",
+            codama_nodes::NumberTypeNode::le(codama_nodes::NumberFormat::U64),
+        )]),
+    );
+    let program_a = ProgramNode::default().add_event(first);
+    let program_b = ProgramNode::default().add_event(second.clone());
+    assert_eq!(
+        combine_modules(
+            CombineModulesInput::new()
+                .set_initial_node(program_a)
+                .add_node(program_b)
+        ),
+        Some(RootNode::new(ProgramNode::default().add_event(second)).into())
+    );
+}

codama-korok-visitors/tests/combine_modules_visitor/mod.rs

@@ -1,6 +1,7 @@
 mod account_node;
 mod defined_type_node;
 mod error_node;
+mod event_node;
 mod instruction_node;
 mod pda_node;
 mod program_directive;