turbopack_ecmascript/side_effect_optimization/facade/

module.rs

use std::collections::BTreeMap;

use anyhow::{Result, bail};
use turbo_tasks::{ResolvedVc, Vc};
use turbopack_core::{
    chunk::{
        AsyncModuleInfo, ChunkableModule, ChunkingContext, EvaluatableAsset, MergeableModule,
        MergeableModules, MergeableModulesExposed,
    },
    ident::AssetIdent,
    module::{Module, ModuleSideEffects},
    module_graph::ModuleGraph,
    reference::ModuleReferences,
    resolve::{ExportUsage, ModulePart},
};

use super::chunk_item::EcmascriptModuleFacadeChunkItem;
use crate::{
    AnalyzeEcmascriptModuleResult, EcmascriptAnalyzable, EcmascriptModuleContent,
    EcmascriptModuleContentOptions, EcmascriptOptions, MergedEcmascriptModule, SpecifiedModuleType,
    chunk::{EcmascriptChunkPlaceable, EcmascriptExports},
    code_gen::CodeGens,
    export::Liveness,
    references::{
        async_module::{AsyncModule, OptionAsyncModule},
        esm::{EsmExport, EsmExports, base::EsmAssetReferences},
    },
    side_effect_optimization::reference::EcmascriptModulePartReference,
};

/// A module derived from an original ecmascript module that only contains all
/// the reexports from that module and also reexports the locals from
/// [EcmascriptModuleLocalsModule]. It allows to follow
#[turbo_tasks::value]
pub struct EcmascriptModuleFacadeModule {
    module: ResolvedVc<Box<dyn EcmascriptChunkPlaceable>>,
    /// The part of the module that this facade represents.
    /// ModulePart::Facade | ModulePart::RenamedExport |
    /// ModulePart::RenamedNamespace
    part: ModulePart,
}

#[turbo_tasks::value_impl]
impl EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    pub fn new(
        module: ResolvedVc<Box<dyn EcmascriptChunkPlaceable>>,
        part: ModulePart,
    ) -> Vc<Self> {
        debug_assert!(
            matches!(
                part,
                ModulePart::Facade
                    | ModulePart::RenamedExport { .. }
                    | ModulePart::RenamedNamespace { .. }
            ),
            "{part:?} is unexpected for EcmascriptModuleFacadeModule"
        );
        EcmascriptModuleFacadeModule { module, part }.cell()
    }

    #[turbo_tasks::function]
    pub async fn async_module(&self) -> Result<Vc<AsyncModule>> {
        let (import_externals, has_top_level_await) =
            if let Some(async_module) = *self.module.get_async_module().await? {
                (
                    async_module.await?.import_externals,
                    async_module.await?.has_top_level_await,
                )
            } else {
                (false, false)
            };
        Ok(AsyncModule {
            has_top_level_await,
            import_externals,
        }
        .cell())
    }
}

impl EcmascriptModuleFacadeModule {
    pub async fn specific_references(
        &self,
    ) -> Result<(
        Vec<ResolvedVc<EcmascriptModulePartReference>>,
        ResolvedVc<EsmAssetReferences>,
    )> {
        Ok(match &self.part {
            ModulePart::Facade => {
                let Some(module) =
                    ResolvedVc::try_sidecast::<Box<dyn EcmascriptAnalyzable>>(self.module)
                else {
                    bail!(
                        "Expected EcmascriptModuleAsset for a EcmascriptModuleFacadeModule with \
                         ModulePart::Facade"
                    );
                };
                let result = module.analyze().await?;
                (
                    vec![
                        // TODO skip if side effect free and no local exports
                        EcmascriptModulePartReference::new_part(
                            *self.module,
                            ModulePart::locals(),
                            ExportUsage::all(),
                        )
                        .to_resolved()
                        .await?,
                    ],
                    result.esm_reexport_references,
                )
            }
            ModulePart::RenamedNamespace { .. } => (
                vec![
                    EcmascriptModulePartReference::new_normal(
                        *self.module,
                        self.part.clone(),
                        ExportUsage::all(),
                    )
                    .to_resolved()
                    .await?,
                ],
                EsmAssetReferences::empty().to_resolved().await?,
            ),
            ModulePart::RenamedExport {
                original_export, ..
            } => (
                vec![
                    EcmascriptModulePartReference::new_normal(
                        *self.module,
                        self.part.clone(),
                        ExportUsage::named(original_export.clone()),
                    )
                    .to_resolved()
                    .await?,
                ],
                EsmAssetReferences::empty().to_resolved().await?,
            ),
            _ => {
                bail!("Unexpected ModulePart for EcmascriptModuleFacadeModule");
            }
        })
    }
}

#[turbo_tasks::value_impl]
impl Module for EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    fn ident(&self) -> Vc<AssetIdent> {
        self.module.ident().with_part(self.part.clone())
    }

    #[turbo_tasks::function]
    fn source(&self) -> Vc<turbopack_core::source::OptionSource> {
        Vc::cell(None)
    }

    #[turbo_tasks::function]
    async fn references(&self) -> Result<Vc<ModuleReferences>> {
        let (part_references, esm_references) = self.specific_references().await?;
        let references = part_references
            .iter()
            .map(|r| ResolvedVc::upcast(*r))
            .chain(esm_references.await?.iter().map(|r| ResolvedVc::upcast(*r)))
            .collect();
        Ok(Vc::cell(references))
    }

    #[turbo_tasks::function]
    async fn is_self_async(self: Vc<Self>) -> Result<Vc<bool>> {
        let async_module = self.async_module();
        let references = self.references();
        let is_self_async = async_module
            .resolve()
            .await?
            .is_self_async(references.resolve().await?)
            .resolve()
            .await?;
        Ok(is_self_async)
    }

    #[turbo_tasks::function]
    fn side_effects(&self) -> Result<Vc<ModuleSideEffects>> {
        Ok(match self.part {
            ModulePart::Facade => self.module.side_effects(),
            ModulePart::RenamedExport { .. } | ModulePart::RenamedNamespace { .. } => {
                ModuleSideEffects::SideEffectFree.cell()
            }
            _ => bail!("Unexpected ModulePart for EcmascriptModuleFacadeModule"),
        })
    }
}

#[turbo_tasks::value_impl]
impl EcmascriptAnalyzable for EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    fn analyze(&self) -> Result<Vc<AnalyzeEcmascriptModuleResult>> {
        bail!("EcmascriptModuleFacadeModule::analyze shouldn't be called");
    }

    #[turbo_tasks::function]
    fn module_content_without_analysis(
        &self,
        _generate_source_map: bool,
    ) -> Result<Vc<EcmascriptModuleContent>> {
        bail!("EcmascriptModuleFacadeModule::module_content_without_analysis shouldn't be called");
    }

    #[turbo_tasks::function]
    async fn module_content_options(
        self: ResolvedVc<Self>,
        chunking_context: ResolvedVc<Box<dyn ChunkingContext>>,
        async_module_info: Option<ResolvedVc<AsyncModuleInfo>>,
    ) -> Result<Vc<EcmascriptModuleContentOptions>> {
        let (part_references, esm_references) = self.await?.specific_references().await?;

        Ok(EcmascriptModuleContentOptions {
            parsed: None,
            module: ResolvedVc::upcast(self),
            specified_module_type: SpecifiedModuleType::EcmaScript,
            chunking_context,
            references: self.references().to_resolved().await?,
            part_references,
            esm_references,
            code_generation: CodeGens::empty().to_resolved().await?,
            async_module: ResolvedVc::cell(Some(self.async_module().to_resolved().await?)),
            // The facade module cannot generate source maps, because the inserted references
            // contain spans from the original module, but the facade module itself doesn't have the
            // original module's swc_common::SourceMap in `parsed`.
            generate_source_map: false,
            original_source_map: None,
            exports: self.get_exports().to_resolved().await?,
            async_module_info,
        }
        .cell())
    }
}

#[turbo_tasks::value_impl]
impl EcmascriptChunkPlaceable for EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    async fn get_exports(&self) -> Result<Vc<EcmascriptExports>> {
        let mut exports = BTreeMap::new();
        let mut star_exports = Vec::new();

        match &self.part {
            ModulePart::Facade => {
                let EcmascriptExports::EsmExports(esm_exports) = *self.module.get_exports().await?
                else {
                    bail!(
                        "EcmascriptModuleFacadeModule must only be used on modules with EsmExports"
                    );
                };
                let esm_exports = esm_exports.await?;
                for (name, export) in &esm_exports.exports {
                    let name = name.clone();
                    match export {
                        EsmExport::LocalBinding(_, liveness) => {
                            exports.insert(
                                name.clone(),
                                EsmExport::ImportedBinding(
                                    ResolvedVc::upcast(
                                        EcmascriptModulePartReference::new_part(
                                            *self.module,
                                            ModulePart::locals(),
                                            ExportUsage::named(name.clone()),
                                        )
                                        .to_resolved()
                                        .await?,
                                    ),
                                    name,
                                    *liveness == Liveness::Mutable,
                                ),
                            );
                        }
                        EsmExport::ImportedNamespace(reference) => {
                            exports.insert(name, EsmExport::ImportedNamespace(*reference));
                        }
                        EsmExport::ImportedBinding(reference, imported_name, mutable) => {
                            exports.insert(
                                name,
                                EsmExport::ImportedBinding(
                                    *reference,
                                    imported_name.clone(),
                                    *mutable,
                                ),
                            );
                        }
                        EsmExport::Error => {
                            exports.insert(name, EsmExport::Error);
                        }
                    }
                }
                star_exports.extend(esm_exports.star_exports.iter().copied());
            }
            ModulePart::RenamedExport {
                original_export,
                export,
            } => {
                exports.insert(
                    export.clone(),
                    EsmExport::ImportedBinding(
                        ResolvedVc::upcast(
                            EcmascriptModulePartReference::new_normal(
                                *self.module,
                                self.part.clone(),
                                ExportUsage::named(original_export.clone()),
                            )
                            .to_resolved()
                            .await?,
                        ),
                        original_export.clone(),
                        false,
                    ),
                );
            }
            ModulePart::RenamedNamespace { export } => {
                exports.insert(
                    export.clone(),
                    EsmExport::ImportedNamespace(ResolvedVc::upcast(
                        EcmascriptModulePartReference::new_normal(
                            *self.module,
                            self.part.clone(),
                            ExportUsage::all(),
                        )
                        .to_resolved()
                        .await?,
                    )),
                );
            }
            _ => bail!("Unexpected ModulePart for EcmascriptModuleFacadeModule"),
        }

        let exports = EsmExports {
            exports,
            star_exports,
        }
        .resolved_cell();
        Ok(EcmascriptExports::EsmExports(exports).cell())
    }

    #[turbo_tasks::function]
    async fn get_async_module(self: Vc<Self>) -> Result<Vc<OptionAsyncModule>> {
        Ok(Vc::cell(Some(self.async_module().to_resolved().await?)))
    }
}

#[turbo_tasks::value_impl]
impl ChunkableModule for EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    fn as_chunk_item(
        self: ResolvedVc<Self>,
        _module_graph: ResolvedVc<ModuleGraph>,
        chunking_context: ResolvedVc<Box<dyn ChunkingContext>>,
    ) -> Result<Vc<Box<dyn turbopack_core::chunk::ChunkItem>>> {
        Ok(Vc::upcast(
            EcmascriptModuleFacadeChunkItem {
                module: self,
                chunking_context,
            }
            .cell(),
        ))
    }
}

#[turbo_tasks::value_impl]
impl EvaluatableAsset for EcmascriptModuleFacadeModule {}

#[turbo_tasks::value_impl]
impl MergeableModule for EcmascriptModuleFacadeModule {
    #[turbo_tasks::function]
    async fn merge(
        self: Vc<Self>,
        modules: Vc<MergeableModulesExposed>,
        entry_points: Vc<MergeableModules>,
    ) -> Result<Vc<Box<dyn ChunkableModule>>> {
        Ok(Vc::upcast(
            *MergedEcmascriptModule::new(
                modules,
                entry_points,
                EcmascriptOptions::default().resolved_cell(),
            )
            .await?,
        ))
    }
}