Refactoring of the type generation/type assertion for provided variables to support internal use case with shared artifacts. (#4429)

Summary:
The main goal is to separate `codegen` and `typegen` for provided variables. Currently, there is an implicit dependency between `typegen` and `codegen` where were generating code for provided variables. The `codegen` expects the local type for provided variables to always be generated as `type ProvidedVariables` so we cam enable inline type assertion as

```
var providedVariables: ProvidedVariables = { ... object  with provided variables ... }
```

However, this approach doesn't work well with the `skip_types` option, where the `typegen` block for an operation is completely skipped (without the `skip_types` we would generate a type for `ProvidedVariables` in it), but the type inline assertion still remains in the `relay-codegen`.

The proposed solution is to make this dependency explicit by passing the generated provided variables object to the method responsible for generating types. Additionally, the type assertion should only be generated in the `relay-typegen`.

 ---
Pull Request resolved: #4429

Test Plan: TBD

Differential Revision: D48801823

Pulled By: alunyov

fbshipit-source-id: 556098bb2ad2457d451b5e77bc38fdb568df2d08

Author: alunyov

compiler/crates/relay-codegen/src/build_ast.rs

@@ -75,14 +75,12 @@ use crate::ast::QueryID;
 use crate::ast::RequestParameters;
 use crate::constants::CODEGEN_CONSTANTS;
 use crate::object;
-use crate::top_level_statements::TopLevelStatements;
 
 pub fn build_request_params_ast_key(
     schema: &SDLSchema,
     request_parameters: RequestParameters<'_>,
     ast_builder: &mut AstBuilder,
     operation: &OperationDefinition,
-    top_level_statements: &TopLevelStatements,
     definition_source_location: WithLocation<StringKey>,
     project_config: &ProjectConfig,
 ) -> AstKey {
@@ -93,7 +91,7 @@ pub fn build_request_params_ast_key(
         project_config,
         definition_source_location,
     );
-    operation_builder.build_request_parameters(operation, request_parameters, top_level_statements)
+    operation_builder.build_request_parameters(operation, request_parameters)
 }
 
 pub fn build_provided_variables(
@@ -1837,7 +1835,6 @@ impl<'schema, 'builder, 'config> CodegenBuilder<'schema, 'builder, 'config> {
         &mut self,
         operation: &OperationDefinition,
         request_parameters: RequestParameters<'_>,
-        top_level_statements: &TopLevelStatements,
     ) -> AstKey {
         let mut metadata_items: Vec<ObjectEntry> = operation
             .directives
@@ -1926,20 +1923,10 @@ impl<'schema, 'builder, 'config> CodegenBuilder<'schema, 'builder, 'config> {
             },
         });
 
-        let provided_variables = if top_level_statements
-            .contains(CODEGEN_CONSTANTS.provided_variables_definition.lookup())
-        {
-            Some(Primitive::Variable(
-                CODEGEN_CONSTANTS.provided_variables_definition,
-            ))
-        } else {
-            self.build_operation_provided_variables(operation)
-                .map(Primitive::Key)
-        };
-        if let Some(value) = provided_variables {
+        if let Some(provided_variables) = self.build_operation_provided_variables(operation) {
             params_object.push(ObjectEntry {
                 key: CODEGEN_CONSTANTS.provided_variables,
-                value,
+                value: Primitive::Key(provided_variables),
             });
         }
 

compiler/crates/relay-codegen/src/constants.rs

@@ -90,7 +90,6 @@ pub struct CodegenConstants {
     pub passing_value: StringKey,
     pub path: StringKey,
     pub plural: StringKey,
-    pub provided_variables_definition: StringKey,
     pub provided_variables: StringKey,
     pub provider: StringKey,
     pub query: StringKey,
@@ -200,7 +199,6 @@ lazy_static! {
         passing_value: "passingValue".intern(),
         path: "path".intern(),
         plural: "plural".intern(),
-        provided_variables_definition: "providedVariablesDefinition".intern(),
         provided_variables: "providedVariables".intern(),
         provider: "provider".intern(),
         query: "query".intern(),

compiler/crates/relay-codegen/src/lib.rs

@@ -28,6 +28,7 @@ pub use build_ast::CodegenVariant;
 pub use constants::CODEGEN_CONSTANTS;
 pub use printer::print_fragment;
 pub use printer::print_operation;
+pub use printer::print_provided_variables;
 pub use printer::print_request;
 pub use printer::print_request_params;
 pub use printer::JSONPrinter;

compiler/crates/relay-codegen/src/printer.rs

@@ -94,21 +94,37 @@ pub fn print_request_params(
 ) -> String {
     let mut request_parameters = build_request_params(operation);
     request_parameters.id = query_id;
-
-    let mut builder = AstBuilder::default();
+    let mut builder: AstBuilder = AstBuilder::default();
     let request_parameters_ast_key = build_request_params_ast_key(
         schema,
         request_parameters,
         &mut builder,
         operation,
-        top_level_statements,
         operation.name.map(|x| x.0),
         project_config,
     );
     let printer = JSONPrinter::new(&builder, project_config, top_level_statements);
     printer.print(request_parameters_ast_key, false)
 }
 
+pub fn print_provided_variables(
+    schema: &SDLSchema,
+    operation: &OperationDefinition,
+    project_config: &ProjectConfig,
+) -> Option<String> {
+    let mut top_level_statements = Default::default();
+    let mut builder = AstBuilder::default();
+    let maybe_provided_variables = build_provided_variables(
+        schema,
+        &mut builder,
+        operation,
+        operation.name.map(|x| x.0),
+        project_config,
+    )?;
+    let printer = JSONPrinter::new(&builder, project_config, &mut top_level_statements);
+    Some(printer.print(maybe_provided_variables, false))
+}
+
 pub struct Printer<'p> {
     project_config: &'p ProjectConfig,
     builder: AstBuilder,
@@ -138,15 +154,15 @@ impl<'p> Printer<'p> {
         operation: &OperationDefinition,
         top_level_statements: &mut TopLevelStatements,
     ) -> Option<String> {
-        let key = build_provided_variables(
+        let provided_variables = build_provided_variables(
             schema,
             &mut self.builder,
             operation,
             operation.name.map(|x| x.0),
             self.project_config,
         )?;
         let printer = JSONPrinter::new(&self.builder, self.project_config, top_level_statements);
-        Some(printer.print(key, self.dedupe))
+        Some(printer.print(provided_variables, self.dedupe))
     }
 
     pub fn print_updatable_query(
@@ -189,7 +205,6 @@ impl<'p> Printer<'p> {
             request_parameters,
             &mut self.builder,
             operation,
-            top_level_statements,
             operation.name.map(|x| x.0),
             self.project_config,
         );
@@ -253,7 +268,6 @@ impl<'p> Printer<'p> {
             request_parameters,
             &mut self.builder,
             operation,
-            top_level_statements,
             operation.name.map(|x| x.0),
             self.project_config,
         );

compiler/crates/relay-compiler-playground/src/lib.rs

@@ -18,6 +18,7 @@ use graphql_text_printer::PrinterOptions;
 use intern::string_key::Intern;
 use relay_codegen::print_fragment;
 use relay_codegen::print_operation;
+use relay_codegen::print_provided_variables;
 use relay_config::ProjectConfig;
 use relay_schema::build_schema_with_extensions;
 use relay_transforms::apply_transforms;
@@ -254,6 +255,7 @@ pub fn parse_to_types_impl(
                 &schema,
                 &project_config,
                 &fragment_locations,
+                print_provided_variables(&schema, normalization_operation, &project_config),
             )
         }))
         .collect::<Vec<_>>()

compiler/crates/relay-compiler/src/artifact_content/content.rs

@@ -14,12 +14,9 @@ use common::NamedItem;
 use graphql_ir::FragmentDefinition;
 use graphql_ir::FragmentDefinitionName;
 use graphql_ir::OperationDefinition;
-use intern::Lookup;
 use relay_codegen::build_request_params;
 use relay_codegen::Printer;
 use relay_codegen::QueryID;
-use relay_codegen::TopLevelStatement;
-use relay_codegen::CODEGEN_CONSTANTS;
 use relay_transforms::is_operation_preloadable;
 use relay_transforms::RelayDataDrivenDependencyMetadata;
 use relay_transforms::ASSIGNABLE_DIRECTIVE;
@@ -111,6 +108,7 @@ pub fn generate_updatable_query(
                 schema,
                 project_config,
                 fragment_locations,
+                None, // TODO: Add/investigrate support for provided variables in updatable queries
             )
         )?;
     }
@@ -129,7 +127,7 @@ pub fn generate_updatable_query(
         &project_config.typegen_config.language,
         &mut section,
         "node",
-        generated_types.ast_type,
+        Some(generated_types.ast_type),
         &request,
     )?;
     content_sections.push(ContentSection::Generic(section));
@@ -264,7 +262,14 @@ pub fn generate_operation(
         "relay-runtime",
     )?;
 
+    // -- Generate provided variables --
+    let mut top_level_statements = Default::default();
     if !skip_types {
+        let maybe_provided_variables = printer.print_provided_variables(
+            schema,
+            normalization_operation,
+            &mut top_level_statements,
+        );
         write!(
             section,
             "{}",
@@ -274,6 +279,7 @@ pub fn generate_operation(
                 schema,
                 project_config,
                 fragment_locations,
+                maybe_provided_variables,
             )
         )?;
     }
@@ -286,25 +292,11 @@ pub fn generate_operation(
 
     // -- Begin Top Level Statements Section --
     let mut section = GenericSection::default();
-    let mut top_level_statements = Default::default();
-    if let Some(provided_variables) =
-        printer.print_provided_variables(schema, normalization_operation, &mut top_level_statements)
-    {
-        let mut provided_variable_text = String::new();
-        write_variable_value_with_type(
-            &project_config.typegen_config.language,
-            &mut provided_variable_text,
-            CODEGEN_CONSTANTS.provided_variables_definition.lookup(),
-            relay_typegen::PROVIDED_VARIABLE_TYPE,
-            &provided_variables,
-        )
-        .unwrap();
-        top_level_statements.insert(
-            CODEGEN_CONSTANTS.provided_variables_definition.to_string(),
-            TopLevelStatement::VariableDefinition(provided_variable_text),
-        );
-    }
+    write!(section, "{}", &top_level_statements)?;
+    content_sections.push(ContentSection::Generic(section));
+    // -- End Top Level Statements Section --
 
+    // -- Begin Query Node Section --
     let request = printer.print_request(
         schema,
         normalization_operation,
@@ -313,17 +305,12 @@ pub fn generate_operation(
         &mut top_level_statements,
     );
 
-    write!(section, "{}", &top_level_statements)?;
-    content_sections.push(ContentSection::Generic(section));
-    // -- End Top Level Statements Section --
-
-    // -- Begin Query Node Section --
     let mut section = GenericSection::default();
     write_variable_value_with_type(
         &project_config.typegen_config.language,
         &mut section,
         "node",
-        generated_types.ast_type,
+        Some(generated_types.ast_type),
         &request,
     )?;
     content_sections.push(ContentSection::Generic(section));
@@ -469,7 +456,7 @@ pub fn generate_split_operation(
         &project_config.typegen_config.language,
         &mut section,
         "node",
-        "NormalizationSplitOperation",
+        Some("NormalizationSplitOperation"),
         &operation,
     )?;
     content_sections.push(ContentSection::Generic(section));
@@ -631,7 +618,7 @@ fn generate_read_only_fragment(
         &project_config.typegen_config.language,
         &mut section,
         "node",
-        generated_types.ast_type,
+        Some(generated_types.ast_type),
         &fragment,
     )?;
     content_sections.push(ContentSection::Generic(section));
@@ -726,7 +713,7 @@ fn generate_assignable_fragment(
         &project_config.typegen_config.language,
         &mut section,
         "node",
-        "any",
+        Some("any"),
         "{}",
     )?;
     content_sections.push(ContentSection::Generic(section));
@@ -774,17 +761,17 @@ fn write_variable_value_with_type(
     language: &TypegenLanguage,
     section: &mut dyn Write,
     variable_name: &str,
-    type_: &str,
+    type_: Option<&str>,
     value: &str,
 ) -> FmtResult {
-    match language {
-        TypegenLanguage::JavaScript => writeln!(section, "var {} = {};", variable_name, value),
-        TypegenLanguage::Flow => {
+    match (language, type_) {
+        (TypegenLanguage::Flow, Some(type_)) => {
             writeln!(section, "var {}/*: {}*/ = {};", variable_name, type_, value)
         }
-        TypegenLanguage::TypeScript => {
+        (TypegenLanguage::TypeScript, Some(type_)) => {
             writeln!(section, "const {}: {} = {};", variable_name, type_, value)
         }
+        (_, _) => writeln!(section, "var {} = {};", variable_name, value),
     }
 }
 

compiler/crates/relay-typegen/src/flow.rs

@@ -85,10 +85,10 @@ impl Writer for FlowPrinter {
         "FragmentType"
     }
 
-    fn write_local_type(&mut self, name: &str, value: &AST) -> FmtResult {
-        write!(&mut self.result, "type {} = ", name)?;
+    fn write_type_assertion(&mut self, name: &str, value: &AST) -> FmtResult {
+        write!(&mut self.result, "({}: ", name)?;
         self.write(value)?;
-        writeln!(&mut self.result, ";")
+        writeln!(&mut self.result, ");")
     }
 
     fn write_export_type(&mut self, name: &str, value: &AST) -> FmtResult {

compiler/crates/relay-typegen/src/javascript.rs

@@ -35,7 +35,7 @@ impl Writer for JavaScriptPrinter {
         ""
     }
 
-    fn write_local_type(&mut self, _name: &str, _value: &AST) -> FmtResult {
+    fn write_type_assertion(&mut self, _name: &str, _value: &AST) -> FmtResult {
         Ok(())
     }
 

compiler/crates/relay-typegen/src/lib.rs

@@ -44,7 +44,6 @@ static REACT_RELAY_MULTI_ACTOR: &str = "react-relay/multi-actor";
 static RELAY_RUNTIME: &str = "relay-runtime";
 static LOCAL_3D_PAYLOAD: &str = "Local3DPayload";
 static ACTOR_CHANGE_POINT: &str = "ActorChangePoint";
-pub static PROVIDED_VARIABLE_TYPE: &str = "ProvidedVariablesType";
 static VALIDATOR_EXPORT_NAME: &str = "validate";
 static LIVE_RESOLVERS_LIVE_STATE: &str = "LiveState";
 static LIVE_RESOLVERS_EXPERIMENTAL_STORE_PATH: &str =
@@ -171,6 +170,7 @@ pub fn generate_operation_type_exports_section(
     schema: &SDLSchema,
     project_config: &ProjectConfig,
     fragment_locations: &FragmentLocations,
+    maybe_provided_variables: Option<String>,
 ) -> String {
     let typegen_context = TypegenContext::new(
         schema,
@@ -192,6 +192,7 @@ pub fn generate_operation_type_exports_section(
         typegen_operation,
         normalization_operation,
         &mut writer,
+        maybe_provided_variables,
     )
     .unwrap();
     writer.into_string()

compiler/crates/relay-typegen/src/typescript.rs

@@ -91,10 +91,10 @@ impl Writer for TypeScriptPrinter {
         }
     }
 
-    fn write_local_type(&mut self, name: &str, value: &AST) -> FmtResult {
-        write!(&mut self.result, "type {} = ", name)?;
+    fn write_type_assertion(&mut self, name: &str, value: &AST) -> FmtResult {
+        write!(&mut self.result, "({} as ", name)?;
         self.write(value)?;
-        writeln!(&mut self.result, ";")
+        writeln!(&mut self.result, ");")
     }
 
     fn write_export_type(&mut self, name: &str, value: &AST) -> FmtResult {