luaur-analysis 0.1.3

Luau type checker and type inference (Rust).
Documentation
use crate::enums::subtyping_suppression_policy::SubtypingSuppressionPolicy;
use crate::enums::table_state::TableState;
use crate::enums::type_field::TypeField;
use crate::records::property_type::Property;
use crate::records::property_type_path::Property as PathProperty;
use crate::records::scope::Scope;
use crate::records::subtyping::Subtyping;
use crate::records::subtyping_environment::SubtypingEnvironment;
use crate::records::subtyping_result::SubtypingResult;
use crate::records::table_type::TableType;
use crate::type_aliases::component::Component;
use alloc::string::ToString;
use alloc::vec::Vec;
use luaur_common::FFlag;

fn path_property(name: &str, is_read: bool) -> Component {
    Component::Property(PathProperty {
        name: name.to_string(),
        is_read,
    })
}

fn index_result_component() -> Component {
    Component::TypeField(TypeField::IndexResult)
}

impl Subtyping {
    pub fn is_covariant_with_deprecated(
        &mut self,
        env: &mut SubtypingEnvironment,
        sub_table: &TableType,
        super_table: &TableType,
        force_covariant_test: bool,
        scope: *mut Scope,
    ) -> SubtypingResult {
        let mut result = SubtypingResult {
            is_subtype: true,
            ..Default::default()
        };

        if sub_table.props.is_empty()
            && sub_table.indexer.is_none()
            && sub_table.state == TableState::Sealed
            && super_table.indexer.is_some()
        {
            return SubtypingResult {
                is_subtype: false,
                ..Default::default()
            };
        }

        for (name, super_prop) in &super_table.props {
            let mut results = Vec::new();

            if let Some(sub_prop) = sub_table.props.get(name) {
                results.push(
                    self.is_covariant_with_subtyping_environment_property_property_string_bool_not_null_scope(
                        env,
                        sub_prop,
                        super_prop,
                        name,
                        force_covariant_test,
                        scope,
                    ),
                );
            } else if let Some(sub_indexer) = &sub_table.indexer {
                let can_index_by_string = unsafe {
                    self.is_covariant_with_subtyping_environment_type_id_type_id_not_null_scope(
                        env,
                        (*self.builtin_types).stringType,
                        sub_indexer.index_type,
                        scope,
                    )
                    .is_subtype
                };

                if can_index_by_string {
                    if super_prop.is_shared() {
                        if FFlag::LuauReadOnlyIndexers.get() && sub_indexer.is_read_only {
                            let mut sr = SubtypingResult {
                                is_subtype: false,
                                ..Default::default()
                            };
                            sr.with_sub_component(index_result_component());
                            sr.with_super_component(path_property(name, true));
                            results.push(sr);
                        } else {
                            let mut sr = self
                                .is_invariant_with_subtyping_environment_sub_ty_super_ty_not_null_scope(
                                    env,
                                    sub_indexer.index_result_type,
                                    super_prop.read_ty.unwrap(),
                                    scope,
                                );
                            sr.with_sub_component(index_result_component());
                            sr.with_super_component(path_property(name, true));
                            results.push(sr);
                        }
                    } else {
                        if let Some(super_read_ty) = super_prop.read_ty {
                            let mut sr = self
                                .is_covariant_with_subtyping_environment_type_id_type_id_not_null_scope(
                                    env,
                                    sub_indexer.index_result_type,
                                    super_read_ty,
                                    scope,
                                );
                            sr.with_sub_component(index_result_component());
                            sr.with_super_component(path_property(name, true));
                            results.push(sr);
                        }

                        if let Some(super_write_ty) = super_prop.write_ty {
                            if FFlag::LuauReadOnlyIndexers.get() && sub_indexer.is_read_only {
                                let mut sr = SubtypingResult {
                                    is_subtype: false,
                                    ..Default::default()
                                };
                                sr.with_sub_component(index_result_component());
                                sr.with_super_component(path_property(name, false));
                                results.push(sr);
                            } else {
                                let mut sr = self
                                    .is_contravariant_with_subtyping_environment_sub_ty_super_ty_not_null_scope(
                                        env,
                                        sub_indexer.index_result_type,
                                        super_write_ty,
                                        scope,
                                    );
                                sr.with_sub_component(index_result_component());
                                sr.with_super_component(path_property(name, false));
                                results.push(sr);
                            }
                        }
                    }
                }
            } else if FFlag::LuauSubtypingMissingPropertiesAsNil.get() {
                let nil_prop = unsafe { Property::readonly((*self.builtin_types).nilType) };
                let mut sr =
                    self.is_covariant_with_subtyping_environment_property_property_string_bool_not_null_scope(
                        env,
                        &nil_prop,
                        super_prop,
                        name,
                        force_covariant_test,
                        scope,
                    );
                sr.reasoning.clear();
                results.push(sr);
            }

            if results.is_empty() {
                return SubtypingResult {
                    is_subtype: false,
                    ..Default::default()
                };
            }

            let is_subtype = results.iter().all(|sr| sr.is_subtype);

            if result.is_subtype && !is_subtype {
                for sr in results {
                    result.and_also(sr, SubtypingSuppressionPolicy::Any);
                }
            } else {
                for sr in results {
                    result.and_also(sr, SubtypingSuppressionPolicy::All);
                }
            }
        }

        if let Some(super_indexer) = &super_table.indexer {
            if let Some(sub_indexer) = &sub_table.indexer {
                let indexer_result = if FFlag::LuauReadOnlyIndexers.get() {
                    self.is_covariant_with_subtyping_environment_table_indexer_table_indexer_not_null_scope(
                        env,
                        sub_indexer,
                        super_indexer,
                        scope,
                    )
                } else {
                    self.is_invariant_with_subtyping_environment_sub_ty_super_ty_not_null_scope(
                        env,
                        *sub_indexer,
                        *super_indexer,
                        scope,
                    )
                };
                result.and_also(indexer_result, SubtypingSuppressionPolicy::All);
            } else if sub_table.state != TableState::Sealed {
                return SubtypingResult {
                    is_subtype: true,
                    ..Default::default()
                };
            } else {
                return SubtypingResult {
                    is_subtype: false,
                    ..Default::default()
                };
            }
        }

        result
    }
}