feat(transformer): eliminate ExportSpecifier where refers to a declare declaration

crates/oxc_transformer/src/typescript/annotations.rs

@@ -78,20 +78,20 @@ impl<'a> Traverse<'a> for TypeScriptAnnotations<'a, '_> {
                         // Keep the export declaration if there are no export specifiers
                         true
                     } else {
-                        decl.specifiers.retain(|specifier| {
-                            !(specifier.export_kind.is_type()
-                                || self.type_identifier_names.contains(&specifier.exported.name())
-                                || matches!(
-                                    &specifier.local, ModuleExportName::IdentifierReference(ident)
-                                    if ctx.scoping().get_reference(ident.reference_id()).is_type()
-                                ))
-                        });
+                        decl.specifiers
+                            .retain(|specifier| self.can_retain_export_specifier(specifier, ctx));
                         // Keep the export declaration if there are still specifiers after removing type exports
                         !decl.specifiers.is_empty()
                     }
                 }
                 Statement::ExportAllDeclaration(decl) => !decl.export_kind.is_type(),
-                Statement::ExportDefaultDeclaration(decl) => !decl.is_typescript_syntax(),
+                Statement::ExportDefaultDeclaration(decl) => {
+                    !decl.is_typescript_syntax()
+                        && !matches!(
+                            &decl.declaration,
+                            ExportDefaultDeclarationKind::Identifier(ident) if Self::is_refers_to_type(ident, ctx)
+                        )
+                }
                 Statement::ImportDeclaration(decl) => {
                     if decl.import_kind.is_type() {
                         false
@@ -614,6 +614,30 @@ impl<'a> TypeScriptAnnotations<'a, '_> {
 
         self.is_jsx_imports(&id.name)
     }
+
+    fn can_retain_export_specifier(
+        &self,
+        specifier: &ExportSpecifier<'a>,
+        ctx: &TraverseCtx<'a>,
+    ) -> bool {
+        if specifier.export_kind.is_type()
+            || self.type_identifier_names.contains(&specifier.exported.name())
+        {
+            return false;
+        }
+        !matches!(&specifier.local, ModuleExportName::IdentifierReference(ident) if Self::is_refers_to_type(ident, ctx))
+    }
+
+    fn is_refers_to_type(ident: &IdentifierReference<'a>, ctx: &TraverseCtx<'a>) -> bool {
+        let scoping = ctx.scoping();
+        let reference = scoping.get_reference(ident.reference_id());
+
+        reference.symbol_id().is_some_and(|symbol_id| {
+            reference.is_type()
+                || scoping.symbol_flags(symbol_id).is_ambient()
+                    && scoping.symbol_redeclarations(symbol_id).iter().all(|r| r.flags.is_ambient())
+        })
+    }
 }
 
 struct Assignment<'a> {

tasks/coverage/snapshots/semantic_babel.snap

@@ -1498,15 +1498,6 @@ rebuilt        : ScopeId(0): []
 Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "foo":
-after transform: SymbolId(0) "foo"
-rebuilt        : <None>
-Reference flags mismatch for "foo":
-after transform: ReferenceId(0): ReferenceFlags(Read)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["foo"]
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/scope/export-declare-function-before/input.ts
 semantic error: Bindings mismatch:
@@ -1515,15 +1506,6 @@ rebuilt        : ScopeId(0): []
 Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "foo":
-after transform: SymbolId(0) "foo"
-rebuilt        : <None>
-Reference flags mismatch for "foo":
-after transform: ReferenceId(0): ReferenceFlags(Read)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["foo"]
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/scope/export-enum-after/input.ts
 semantic error: Scope flags mismatch:

tasks/coverage/snapshots/semantic_typescript.snap

@@ -361,15 +361,6 @@ tasks/coverage/typescript/tests/cases/compiler/allowSyntheticDefaultImportsCanPa
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "Color":
-after transform: SymbolId(0) "Color"
-rebuilt        : <None>
-Reference flags mismatch for "Color":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["Color"]
 
 tasks/coverage/typescript/tests/cases/compiler/ambientClassDeclarationWithExtends.ts
 semantic error: Bindings mismatch:
@@ -8163,29 +8154,11 @@ tasks/coverage/typescript/tests/cases/compiler/declarationEmitToDeclarationDirWi
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "Foo":
-after transform: SymbolId(0) "Foo"
-rebuilt        : <None>
-Reference flags mismatch for "Foo":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["Foo"]
 
 tasks/coverage/typescript/tests/cases/compiler/declarationEmitToDeclarationDirWithDeclarationOption.ts
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "Foo":
-after transform: SymbolId(0) "Foo"
-rebuilt        : <None>
-Reference flags mismatch for "Foo":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["Foo"]
 
 tasks/coverage/typescript/tests/cases/compiler/declarationEmitTopLevelNodeFromCrossFile.ts
 semantic error: Scope children mismatch:
@@ -8291,15 +8264,6 @@ tasks/coverage/typescript/tests/cases/compiler/declarationEmitWithComposite.ts
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "Foo":
-after transform: SymbolId(0) "Foo"
-rebuilt        : <None>
-Reference flags mismatch for "Foo":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["Foo"]
 
 tasks/coverage/typescript/tests/cases/compiler/declarationEmitWithDefaultAsComputedName.ts
 semantic error: Bindings mismatch:
@@ -13152,15 +13116,6 @@ rebuilt        : ScopeId(0): []
 Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "m":
-after transform: SymbolId(0) "m"
-rebuilt        : <None>
-Reference flags mismatch for "m":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["m"]
 
 tasks/coverage/typescript/tests/cases/compiler/exportDefaultImportedType.ts
 semantic error: Scope children mismatch:
@@ -20643,15 +20598,6 @@ tasks/coverage/typescript/tests/cases/compiler/moduleAugmentationOfAlias.ts
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "I":
-after transform: SymbolId(0) "I"
-rebuilt        : <None>
-Reference flags mismatch for "I":
-after transform: ReferenceId(0): ReferenceFlags(Type)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["I"]
 
 tasks/coverage/typescript/tests/cases/compiler/moduleAugmentationsBundledOutput1.ts
 semantic error: Scope children mismatch:
@@ -28735,15 +28681,9 @@ rebuilt        : ScopeId(0): []
 Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1), ScopeId(2), ScopeId(4), ScopeId(6), ScopeId(7), ScopeId(8), ScopeId(14), ScopeId(16), ScopeId(19)]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "spected":
-after transform: SymbolId(0) "spected"
-rebuilt        : <None>
-Reference flags mismatch for "spected":
-after transform: ReferenceId(73): ReferenceFlags(Read)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
 Unresolved references mismatch:
 after transform: ["Array", "Partial", "ReadonlyArray"]
-rebuilt        : ["spected"]
+rebuilt        : []
 
 tasks/coverage/typescript/tests/cases/compiler/specializationError.ts
 semantic error: Scope children mismatch:
@@ -31954,15 +31894,6 @@ tasks/coverage/typescript/tests/cases/compiler/uniqueSymbolPropertyDeclarationEm
 semantic error: Bindings mismatch:
 after transform: ScopeId(0): ["Op"]
 rebuilt        : ScopeId(0): []
-Reference symbol mismatch for "Op":
-after transform: SymbolId(0) "Op"
-rebuilt        : <None>
-Reference flags mismatch for "Op":
-after transform: ReferenceId(0): ReferenceFlags(Read)
-rebuilt        : ReferenceId(0): ReferenceFlags(Read | Type)
-Unresolved references mismatch:
-after transform: []
-rebuilt        : ["Op"]
 
 tasks/coverage/typescript/tests/cases/compiler/unknownLikeUnionObjectFlagsNotPropagated.ts
 semantic error: Scope children mismatch:

tasks/transform_conformance/snapshots/babel.snap.md

@@ -1727,7 +1727,36 @@ after transform: SymbolId(3): [Span { start: 147, end: 154 }, Span { start: 225,
 rebuilt        : SymbolId(2): []
 
 * exports/declared-types/input.ts
-x Output mismatch
+Bindings mismatch:
+after transform: ScopeId(0): ["BB", "BB2", "C", "C2", "E", "M", "N", "f", "foo", "x"]
+rebuilt        : ScopeId(0): ["BB", "BB2", "C2", "foo"]
+Scope children mismatch:
+after transform: ScopeId(0): [ScopeId(1), ScopeId(2), ScopeId(3), ScopeId(4), ScopeId(5), ScopeId(6), ScopeId(7), ScopeId(8), ScopeId(9), ScopeId(10), ScopeId(11), ScopeId(12), ScopeId(13), ScopeId(14), ScopeId(15), ScopeId(16), ScopeId(17), ScopeId(18)]
+rebuilt        : ScopeId(0): [ScopeId(1), ScopeId(2), ScopeId(3), ScopeId(4), ScopeId(5)]
+Bindings mismatch:
+after transform: ScopeId(12): ["BB", "K"]
+rebuilt        : ScopeId(2): ["BB"]
+Scope flags mismatch:
+after transform: ScopeId(12): ScopeFlags(StrictMode)
+rebuilt        : ScopeId(2): ScopeFlags(StrictMode | Function)
+Bindings mismatch:
+after transform: ScopeId(13): ["BB", "L"]
+rebuilt        : ScopeId(3): ["BB"]
+Scope flags mismatch:
+after transform: ScopeId(13): ScopeFlags(StrictMode)
+rebuilt        : ScopeId(3): ScopeFlags(StrictMode | Function)
+Scope flags mismatch:
+after transform: ScopeId(16): ScopeFlags(StrictMode)
+rebuilt        : ScopeId(4): ScopeFlags(StrictMode | Function)
+Symbol flags mismatch for "BB":
+after transform: SymbolId(11): SymbolFlags(RegularEnum)
+rebuilt        : SymbolId(1): SymbolFlags(FunctionScopedVariable)
+Symbol redeclarations mismatch for "BB":
+after transform: SymbolId(11): [Span { start: 479, end: 481 }, Span { start: 495, end: 497 }]
+rebuilt        : SymbolId(1): []
+Symbol flags mismatch for "BB2":
+after transform: SymbolId(16): SymbolFlags(RegularEnum)
+rebuilt        : SymbolId(4): SymbolFlags(FunctionScopedVariable)
 
 * exports/default-function/input.ts
 Scope children mismatch: