fix(transformer/typescript): retain TSImportEqualsDeclaration in name…

…space when its binding has been referenced or onlyRemoveTypeImports is true

crates/oxc_transformer/src/typescript/namespace.rs

@@ -1,3 +1,4 @@
+use oxc_semantic::Reference;
 use rustc_hash::FxHashSet;
 
 use oxc_allocator::{Box as ArenaBox, Vec as ArenaVec};
@@ -23,11 +24,16 @@ pub struct TypeScriptNamespace<'a, 'ctx> {
 
     // Options
     allow_namespaces: bool,
+    only_remove_type_imports: bool,
 }
 
 impl<'a, 'ctx> TypeScriptNamespace<'a, 'ctx> {
     pub fn new(options: &TypeScriptOptions, ctx: &'ctx TransformCtx<'a>) -> Self {
-        Self { ctx, allow_namespaces: options.allow_namespaces }
+        Self {
+            ctx,
+            allow_namespaces: options.allow_namespaces,
+            only_remove_type_imports: options.only_remove_type_imports,
+        }
     }
 }
 
@@ -274,9 +280,20 @@ impl<'a> TypeScriptNamespace<'a, '_> {
                 | Statement::TSEnumDeclaration(_) => {
                     names.insert(stmt.to_declaration().id().as_ref().unwrap().name.clone());
                 }
-                Statement::TSTypeAliasDeclaration(_)
-                | Statement::TSInterfaceDeclaration(_)
-                | Statement::TSImportEqualsDeclaration(_) => continue,
+                // Retain when `only_remove_type_imports` is true or there are value references
+                // The behavior is the same as `TypeScriptModule::transform_ts_import_equals`
+                Statement::TSImportEqualsDeclaration(decl)
+                    if !self.only_remove_type_imports
+                        && ctx
+                            .symbols()
+                            .get_resolved_references(decl.id.symbol_id())
+                            .all(Reference::is_type) =>
+                {
+                    continue;
+                }
+                Statement::TSTypeAliasDeclaration(_) | Statement::TSInterfaceDeclaration(_) => {
+                    continue
+                }
                 _ => {}
             }
             new_stmts.push(stmt);

tasks/transform_conformance/snapshots/oxc.snap.md

@@ -1,6 +1,6 @@
 commit: 54a8389f
 
-Passed: 126/145
+Passed: 126/147
 
 # All Passed:
 * babel-plugin-transform-class-static-block
@@ -47,7 +47,7 @@ after transform: SymbolId(0): [ReferenceId(0), ReferenceId(2), ReferenceId(6), R
 rebuilt        : SymbolId(0): [ReferenceId(0), ReferenceId(2), ReferenceId(6), ReferenceId(10)]
 
 
-# babel-plugin-transform-typescript (2/11)
+# babel-plugin-transform-typescript (2/13)
 * class-property-definition/input.ts
 Unresolved references mismatch:
 after transform: ["const"]
@@ -159,6 +159,65 @@ Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1)]
 rebuilt        : ScopeId(0): []
 
+* namespace/import-=/input.ts
+Missing SymbolId: "N1"
+Missing SymbolId: "_N"
+Missing ReferenceId: "N1"
+Missing ReferenceId: "N1"
+Missing SymbolId: "N2"
+Missing SymbolId: "_N2"
+Missing SymbolId: "X"
+Missing ReferenceId: "N2"
+Missing ReferenceId: "N2"
+Binding symbols mismatch:
+after transform: ScopeId(0): [SymbolId(0), SymbolId(1), SymbolId(4)]
+rebuilt        : ScopeId(0): [SymbolId(0), SymbolId(1), SymbolId(4)]
+Bindings mismatch:
+after transform: ScopeId(1): ["V", "X", "_N"]
+rebuilt        : ScopeId(1): ["V", "_N"]
+Scope flags mismatch:
+after transform: ScopeId(1): ScopeFlags(StrictMode | Function)
+rebuilt        : ScopeId(1): ScopeFlags(Function)
+Binding symbols mismatch:
+after transform: ScopeId(2): [SymbolId(5), SymbolId(6), SymbolId(8)]
+rebuilt        : ScopeId(2): [SymbolId(5), SymbolId(6), SymbolId(7)]
+Scope flags mismatch:
+after transform: ScopeId(2): ScopeFlags(StrictMode | Function)
+rebuilt        : ScopeId(2): ScopeFlags(Function)
+Symbol reference IDs mismatch for "A":
+after transform: SymbolId(0): [ReferenceId(0), ReferenceId(1)]
+rebuilt        : SymbolId(0): [ReferenceId(2)]
+Reference symbol mismatch for "X":
+after transform: SymbolId(5) "X"
+rebuilt        : SymbolId(6) "X"
+
+* namespace/preserve-import-=/input.ts
+Missing SymbolId: "N1"
+Missing SymbolId: "_N"
+Missing SymbolId: "Foo"
+Missing ReferenceId: "N1"
+Missing ReferenceId: "N1"
+Missing SymbolId: "N2"
+Missing SymbolId: "_N2"
+Missing SymbolId: "Foo"
+Missing ReferenceId: "N2"
+Missing ReferenceId: "N2"
+Binding symbols mismatch:
+after transform: ScopeId(0): [SymbolId(0), SymbolId(1), SymbolId(4)]
+rebuilt        : ScopeId(0): [SymbolId(0), SymbolId(1), SymbolId(5)]
+Binding symbols mismatch:
+after transform: ScopeId(1): [SymbolId(2), SymbolId(3), SymbolId(7)]
+rebuilt        : ScopeId(1): [SymbolId(2), SymbolId(3), SymbolId(4)]
+Scope flags mismatch:
+after transform: ScopeId(1): ScopeFlags(StrictMode | Function)
+rebuilt        : ScopeId(1): ScopeFlags(Function)
+Binding symbols mismatch:
+after transform: ScopeId(2): [SymbolId(5), SymbolId(6), SymbolId(8)]
+rebuilt        : ScopeId(2): [SymbolId(6), SymbolId(7), SymbolId(8)]
+Scope flags mismatch:
+after transform: ScopeId(2): ScopeFlags(StrictMode | Function)
+rebuilt        : ScopeId(2): ScopeFlags(Function)
+
 * preserve-import-=/input.js
 Missing SymbolId: "Foo"
 Binding symbols mismatch:

tasks/transform_conformance/tests/babel-plugin-transform-typescript/test/fixtures/namespace/import-=/input.ts

@@ -0,0 +1,13 @@
+import A from 'mod';
+namespace N1 {
+  // Remove because `X` has not been referenced
+  import X = A.B;
+  const V = 0;
+}
+
+namespace N2 {
+  // Retain because `X` has been referenced
+  import X = A.B;
+  const V = X;
+}
+

tasks/transform_conformance/tests/babel-plugin-transform-typescript/test/fixtures/namespace/import-=/output.js

@@ -0,0 +1,11 @@
+import A from 'mod';
+let N1;
+(function (_N) {
+    const V = 0;
+})(N1 || (N1 = {}));
+let N2;
+(function (_N2) {
+    // Retain because `X` has been referenced
+    var X = A.B;
+    const V = X;
+})(N2 || (N2 = {}));

tasks/transform_conformance/tests/babel-plugin-transform-typescript/test/fixtures/namespace/preserve-import-=/input.ts

@@ -0,0 +1,13 @@
+import nsa from "mod";
+
+namespace N1 {
+  // Retain because `onlyRemoveTypeImports` is true
+  import Foo = nsa.bar;
+  const foo = 0;
+}
+
+namespace N2 {
+  // Retain because `onlyRemoveTypeImports` is true
+  import Foo = nsa.bar;
+  const foo: Foo = 0;
+}

tasks/transform_conformance/tests/babel-plugin-transform-typescript/test/fixtures/namespace/preserve-import-=/options.json

@@ -0,0 +1,10 @@
+{
+  "plugins": [
+    [
+      "transform-typescript",
+      {
+        "onlyRemoveTypeImports": true
+      }
+    ]
+  ]
+}

tasks/transform_conformance/tests/babel-plugin-transform-typescript/test/fixtures/namespace/preserve-import-=/output.js

@@ -0,0 +1,15 @@
+import nsa from "mod";
+
+let N1;
+(function(_N) {
+  // Retain because `onlyRemoveTypeImports` is true
+  var Foo = nsa.bar;
+  const foo = 0;
+})(N1 || (N1 = {}));
+
+let N2;
+(function(_N2) {
+  // Retain because `onlyRemoveTypeImports` is true
+  var Foo = nsa.bar;
+  const foo = 0;
+})(N2 || (N2 = {}));