turbopack_ecmascript/references/
pattern_mapping.rs

1use std::{borrow::Cow, collections::HashSet};
2
3use anyhow::Result;
4use bincode::{Decode, Encode};
5use swc_core::{
6    common::DUMMY_SP,
7    ecma::ast::{
8        CallExpr, Callee, Expr, ExprOrSpread, KeyValueProp, Lit, ObjectLit, Prop, PropName,
9        PropOrSpread,
10    },
11    quote, quote_expr,
12};
13use turbo_rcstr::{RcStr, rcstr};
14use turbo_tasks::{
15    FxIndexMap, NonLocalValue, ResolvedVc, TaskInput, TryJoinIterExt, Vc, debug::ValueDebugFormat,
16    trace::TraceRawVcs,
17};
18use turbopack_core::{
19    chunk::{ChunkableModule, ChunkingContext, ModuleChunkItemIdExt, ModuleId},
20    issue::{
21        Issue, IssueExt, IssueSeverity, StyledString, code_gen::CodeGenerationIssue,
22        module::emit_unknown_module_type_error,
23    },
24    resolve::{
25        ExternalType, ModuleResolveResult, ModuleResolveResultItem, origin::ResolveOrigin,
26        parse::Request,
27    },
28};
29
30use crate::{
31    references::util::{
32        request_to_string, throw_module_not_found_error_expr, throw_module_not_found_expr,
33        throw_module_not_found_expr_async,
34    },
35    runtime_functions::{
36        TURBOPACK_ASYNC_LOADER, TURBOPACK_EXTERNAL_IMPORT, TURBOPACK_EXTERNAL_REQUIRE,
37        TURBOPACK_IMPORT, TURBOPACK_MODULE_CONTEXT, TURBOPACK_REQUIRE,
38    },
39    utils::module_id_to_lit,
40};
41
42#[derive(PartialEq, Eq, ValueDebugFormat, TraceRawVcs, NonLocalValue, Encode, Decode)]
43pub(crate) enum SinglePatternMapping {
44    /// Invalid request.
45    Invalid,
46    /// Unresolvable request.
47    Unresolvable(String),
48    /// Ignored request.
49    Ignored,
50    /// Constant request that always maps to the same module.
51    ///
52    /// ### Example
53    /// ```js
54    /// require("./module")
55    /// ```
56    Module(ModuleId),
57    /// Constant request that always maps to the same module.
58    /// This is used for dynamic imports.
59    /// Module id points to a loader module.
60    ///
61    /// ### Example
62    /// ```js
63    /// import("./module")
64    /// ```
65    ModuleLoader(ModuleId),
66    /// External reference with request and type
67    External(RcStr, ExternalType),
68}
69
70/// A mapping from a request pattern (e.g. "./module", `./images/${name}.png`)
71/// to corresponding module ids. The same pattern can map to multiple module ids
72/// at runtime when using variable interpolation.
73#[turbo_tasks::value]
74pub(crate) enum PatternMapping {
75    /// Constant request that always maps to the same module.
76    ///
77    /// ### Example
78    /// ```js
79    /// require("./module")
80    /// ```
81    Single(SinglePatternMapping),
82    /// Variable request that can map to different modules at runtime.
83    ///
84    /// ### Example
85    /// ```js
86    /// require(`./images/${name}.png`)
87    /// ```
88    Map(#[bincode(with = "turbo_bincode::indexmap")] FxIndexMap<String, SinglePatternMapping>),
89}
90
91#[derive(
92    Copy, Clone, Debug, Eq, PartialEq, Hash, TraceRawVcs, TaskInput, NonLocalValue, Encode, Decode,
93)]
94pub(crate) enum ResolveType {
95    AsyncChunkLoader,
96    ChunkItem,
97}
98
99impl SinglePatternMapping {
100    pub fn create_id(&self, key_expr: Cow<'_, Expr>) -> Expr {
101        match self {
102            Self::Invalid => {
103                quote!(
104                    "(() => { throw new Error('could not resolve \"' + $arg + '\" into a module'); })()" as Expr,
105                    arg: Expr = key_expr.into_owned()
106                )
107            }
108            Self::Unresolvable(request) => throw_module_not_found_expr(request),
109            Self::Ignored => {
110                quote!("undefined" as Expr)
111            }
112            Self::Module(module_id) | Self::ModuleLoader(module_id) => module_id_to_lit(module_id),
113            Self::External(s, _) => Expr::Lit(Lit::Str(s.as_str().into())),
114        }
115    }
116
117    pub fn create_require(&self, key_expr: Cow<'_, Expr>) -> Expr {
118        match self {
119            Self::Invalid => self.create_id(key_expr),
120            Self::Unresolvable(request) => throw_module_not_found_expr(request),
121            Self::Ignored => quote!("{}" as Expr),
122            Self::Module(_) | Self::ModuleLoader(_) => quote!(
123                "$turbopack_require($arg)" as Expr,
124                turbopack_require: Expr = TURBOPACK_REQUIRE.into(),
125                arg: Expr = self.create_id(key_expr)
126            ),
127            Self::External(request, ExternalType::CommonJs) => quote!(
128                "$turbopack_external_require($arg, () => require($arg))" as Expr,
129                turbopack_external_require: Expr = TURBOPACK_EXTERNAL_REQUIRE.into(),
130                arg: Expr = request.as_str().into()
131            ),
132            Self::External(request, ty) => throw_module_not_found_error_expr(
133                request,
134                &format!("Unsupported external type {ty:?} for commonjs reference"),
135            ),
136        }
137    }
138
139    pub fn create_import(&self, key_expr: Cow<'_, Expr>, import_externals: bool) -> Expr {
140        match self {
141            Self::Invalid => {
142                let error = quote_expr!(
143                    "() => { throw new Error('could not resolve \"' + $arg + '\" into a module'); }",
144                    arg: Expr = key_expr.into_owned()
145                );
146                Expr::Call(CallExpr {
147                    callee: Callee::Expr(quote_expr!("Promise.resolve().then")),
148                    args: vec![ExprOrSpread {
149                        spread: None,
150                        expr: error,
151                    }],
152                    span: DUMMY_SP,
153                    ..Default::default()
154                })
155            }
156            Self::Unresolvable(request) => throw_module_not_found_expr_async(request),
157            Self::External(_, ExternalType::EcmaScriptModule) => {
158                if import_externals {
159                    Expr::Call(CallExpr {
160                        callee: Callee::Expr(Box::new(TURBOPACK_EXTERNAL_IMPORT.into())),
161                        args: vec![ExprOrSpread {
162                            spread: None,
163                            expr: Box::new(key_expr.into_owned()),
164                        }],
165                        span: DUMMY_SP,
166                        ..Default::default()
167                    })
168                } else {
169                    Expr::Call(CallExpr {
170                        callee: Callee::Expr(quote_expr!("Promise.resolve().then")),
171                        args: vec![ExprOrSpread {
172                            spread: None,
173                            expr: quote_expr!(
174                                "() => $turbopack_external_require($arg, () => require($arg), true)",
175                                turbopack_external_require: Expr = TURBOPACK_EXTERNAL_REQUIRE.into(),
176                                arg: Expr = key_expr.into_owned()
177                            ),
178                        }],
179                        span: DUMMY_SP,
180                        ..Default::default()
181                    })
182                }
183            }
184            Self::External(_, ExternalType::CommonJs | ExternalType::Url) => Expr::Call(CallExpr {
185                callee: Callee::Expr(quote_expr!("Promise.resolve().then")),
186                args: vec![ExprOrSpread {
187                    spread: None,
188                    expr: quote_expr!(
189                        "() => $turbopack_external_require($arg, () => require($arg), true)",
190                        turbopack_external_require: Expr = TURBOPACK_EXTERNAL_REQUIRE.into(),
191                        arg: Expr = key_expr.into_owned()
192                    ),
193                }],
194                span: DUMMY_SP,
195                ..Default::default()
196            }),
197            #[allow(unreachable_patterns)]
198            Self::External(request, ty) => throw_module_not_found_error_expr(
199                request,
200                &format!("Unsupported external type {ty:?} for dynamic import reference"),
201            ),
202            Self::ModuleLoader(module_id) => {
203                quote!("$turbopack_async_loader($id)" as Expr,
204                    turbopack_async_loader: Expr = TURBOPACK_ASYNC_LOADER.into(),
205                    id: Expr = module_id_to_lit(module_id)
206                )
207            }
208            Self::Ignored => {
209                quote!("Promise.resolve({})" as Expr)
210            }
211            Self::Module(_) => Expr::Call(CallExpr {
212                callee: Callee::Expr(quote_expr!("Promise.resolve().then")),
213                args: vec![ExprOrSpread {
214                    spread: None,
215                    expr: quote_expr!(
216                        "() => $turbopack_import($arg)",
217                        turbopack_import: Expr = TURBOPACK_IMPORT.into(),
218                        arg: Expr = self.create_id(key_expr)
219                    ),
220                }],
221                span: DUMMY_SP,
222                ..Default::default()
223            }),
224        }
225    }
226}
227
228enum ImportMode {
229    Require,
230    Import { import_externals: bool },
231}
232
233fn create_context_map(
234    map: &FxIndexMap<String, SinglePatternMapping>,
235    key_expr: &Expr,
236    import_mode: ImportMode,
237) -> Expr {
238    let props = map
239        .iter()
240        .map(|(k, v)| {
241            PropOrSpread::Prop(Box::new(Prop::KeyValue(KeyValueProp {
242                key: PropName::Str(k.as_str().into()),
243                value: quote_expr!(
244                        "{ id: () => $id, module: () => $module }",
245                        id: Expr = v.create_id(Cow::Borrowed(key_expr)),
246                        module: Expr = match import_mode {
247                            ImportMode::Require => v.create_require(Cow::Borrowed(key_expr)),
248                            ImportMode::Import { import_externals } => v.create_import(Cow::Borrowed(key_expr), import_externals),
249                        },
250                    ),
251            })))
252        })
253        .collect();
254
255    Expr::Object(ObjectLit {
256        span: DUMMY_SP,
257        props,
258    })
259}
260
261impl PatternMapping {
262    pub fn create_id(&self, key_expr: Expr) -> Expr {
263        match self {
264            PatternMapping::Single(pm) => pm.create_id(Cow::Owned(key_expr)),
265            PatternMapping::Map(map) => {
266                let map = create_context_map(map, &key_expr, ImportMode::Require);
267
268                quote!("$turbopack_module_context($map).resolve($key)" as Expr,
269                    turbopack_module_context: Expr = TURBOPACK_MODULE_CONTEXT.into(),
270                    map: Expr = map,
271                    key: Expr = key_expr
272                )
273            }
274        }
275    }
276
277    pub fn create_require(&self, key_expr: Expr) -> Expr {
278        match self {
279            PatternMapping::Single(pm) => pm.create_require(Cow::Owned(key_expr)),
280            PatternMapping::Map(map) => {
281                let map = create_context_map(map, &key_expr, ImportMode::Require);
282
283                quote!("$turbopack_module_context($map)($key)" as Expr,
284                    turbopack_module_context: Expr = TURBOPACK_MODULE_CONTEXT.into(),
285                    map: Expr = map,
286                    key: Expr = key_expr
287                )
288            }
289        }
290    }
291
292    pub fn create_import(&self, key_expr: Expr, import_externals: bool) -> Expr {
293        match self {
294            PatternMapping::Single(pm) => pm.create_import(Cow::Owned(key_expr), import_externals),
295            PatternMapping::Map(map) => {
296                let map =
297                    create_context_map(map, &key_expr, ImportMode::Import { import_externals });
298
299                quote!("$turbopack_module_context($map).import($key)" as Expr,
300                    turbopack_module_context: Expr = TURBOPACK_MODULE_CONTEXT.into(),
301                    map: Expr = map,
302                    key: Expr = key_expr
303                )
304            }
305        }
306    }
307}
308
309async fn to_single_pattern_mapping(
310    origin: Vc<Box<dyn ResolveOrigin>>,
311    chunking_context: Vc<Box<dyn ChunkingContext>>,
312    resolve_item: &ModuleResolveResultItem,
313    resolve_type: ResolveType,
314) -> Result<SinglePatternMapping> {
315    let module = match resolve_item {
316        ModuleResolveResultItem::Module(module) => *module,
317        ModuleResolveResultItem::External { name: s, ty, .. } => {
318            return Ok(SinglePatternMapping::External(s.clone(), *ty));
319        }
320        ModuleResolveResultItem::Ignore => return Ok(SinglePatternMapping::Ignored),
321        ModuleResolveResultItem::Unknown(source) => {
322            emit_unknown_module_type_error(**source).await?;
323            return Ok(SinglePatternMapping::Unresolvable(
324                "unknown module type".to_string(),
325            ));
326        }
327        ModuleResolveResultItem::Error(issue) => {
328            return Ok(SinglePatternMapping::Unresolvable(
329                issue.title().await?.to_unstyled_string(),
330            ));
331        }
332        ModuleResolveResultItem::OutputAsset(_)
333        | ModuleResolveResultItem::Empty
334        | ModuleResolveResultItem::Custom(_) => {
335            // TODO implement mapping
336            CodeGenerationIssue {
337                severity: IssueSeverity::Bug,
338                title: StyledString::Text(rcstr!(
339                    "pattern mapping is not implemented for this result"
340                ))
341                .resolved_cell(),
342                message: StyledString::Text(
343                    format!(
344                        "the reference resolves to a non-trivial result, which is not supported \
345                         yet: {resolve_item:?}"
346                    )
347                    .into(),
348                )
349                .resolved_cell(),
350                path: origin.origin_path().owned().await?,
351                source: None,
352            }
353            .resolved_cell()
354            .emit();
355            return Ok(SinglePatternMapping::Invalid);
356        }
357    };
358    if let Some(chunkable) = ResolvedVc::try_downcast::<Box<dyn ChunkableModule>>(module) {
359        match resolve_type {
360            ResolveType::AsyncChunkLoader => {
361                let ident = chunking_context.async_loader_chunk_item_ident(*chunkable);
362                let loader_id = chunking_context
363                    .chunk_item_id_strategy()
364                    .await?
365                    .get_id_from_ident(ident)
366                    .await?;
367                return Ok(SinglePatternMapping::ModuleLoader(loader_id));
368            }
369            ResolveType::ChunkItem => {
370                let item_id = chunkable.chunk_item_id(chunking_context).await?;
371                return Ok(SinglePatternMapping::Module(item_id));
372            }
373        }
374    }
375    CodeGenerationIssue {
376        severity: IssueSeverity::Bug,
377        title: StyledString::Text(rcstr!("non-ecmascript placeable asset")).resolved_cell(),
378        message: StyledString::Text(rcstr!(
379            "asset is not placeable in ESM chunks, so it doesn't have a module id"
380        ))
381        .resolved_cell(),
382        path: origin.origin_path().owned().await?,
383        source: None,
384    }
385    .resolved_cell()
386    .emit();
387    Ok(SinglePatternMapping::Invalid)
388}
389
390#[turbo_tasks::value_impl]
391impl PatternMapping {
392    /// Resolves a request into a pattern mapping.
393    // NOTE(alexkirsz) I would rather have used `resolve` here but it's already reserved by the Vc
394    // impl.
395    #[turbo_tasks::function]
396    pub async fn resolve_request(
397        request: Vc<Request>,
398        origin: Vc<Box<dyn ResolveOrigin>>,
399        chunking_context: Vc<Box<dyn ChunkingContext>>,
400        resolve_result: Vc<ModuleResolveResult>,
401        resolve_type: ResolveType,
402    ) -> Result<Vc<PatternMapping>> {
403        let result = resolve_result.await?;
404        match result.primary.len() {
405            0 => Ok(PatternMapping::Single(SinglePatternMapping::Unresolvable(
406                request_to_string(request).await?.to_string(),
407            ))
408            .cell()),
409            1 if !request.request_pattern().await?.has_dynamic_parts() => {
410                let resolve_item = &result.primary.first().unwrap().1;
411                let single_pattern_mapping =
412                    to_single_pattern_mapping(origin, chunking_context, resolve_item, resolve_type)
413                        .await?;
414                Ok(PatternMapping::Single(single_pattern_mapping).cell())
415            }
416            _ => {
417                let mut set = HashSet::new();
418                let map = result
419                    .primary
420                    .iter()
421                    .filter_map(|(k, v)| {
422                        let request = k.request.as_ref()?;
423                        set.insert(request).then(|| (request.to_string(), v))
424                    })
425                    .map(|(k, v)| async move {
426                        let single_pattern_mapping =
427                            to_single_pattern_mapping(origin, chunking_context, v, resolve_type)
428                                .await?;
429                        Ok((k, single_pattern_mapping))
430                    })
431                    .try_join()
432                    .await?
433                    .into_iter()
434                    .collect();
435                Ok(PatternMapping::Map(map).cell())
436            }
437        }
438    }
439}
turbopack_ecmascript/references/pattern_mapping.rs

turbopack_ecmascript/references/
pattern_mapping.rs
