fix(es/transforms/typescript): Fix strip (#2496)

swc_ecma_transforms_typescript:
 - Visit the RHS of import equals declaration properly.

Cargo.lock

@@ -2981,7 +2981,7 @@ dependencies = [
 
 [[package]]
 name = "swc_ecma_transforms_typescript"
-version = "0.54.0"
+version = "0.54.1"
 dependencies = [
  "serde",
  "swc_atoms 0.2.9",

ecmascript/transforms/typescript/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc_ecma_transforms_typescript"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.54.0"
+version = "0.54.1"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

ecmascript/transforms/typescript/src/strip.rs

@@ -280,6 +280,10 @@ struct DeclInfo {
     has_type: bool,
     /// Var, Fn, Class
     has_concrete: bool,
+    /// In `import foo = bar.baz`, `foo`'s dependency is `bar`. This means that
+    /// when setting `has_concrete` for `foo`, it must also be set for
+    /// `bar`.
+    maybe_dependency: Option<Ident>,
 }
 
 impl<C> Strip<C>
@@ -1370,10 +1374,22 @@ where
     }
 
     fn visit_ident(&mut self, n: &Ident, _: &dyn Node) {
-        let is_type_only_export = self.is_type_only_export;
         let entry = self.scope.referenced_idents.entry(n.to_id()).or_default();
-        entry.has_concrete |= !is_type_only_export;
+        if self.is_type_only_export {
-
+            entry.has_type = true;
+        } else {
+            entry.has_concrete = true;
+        }
+        if let Some(i) = &entry.maybe_dependency {
+            let id = i.to_id();
+            if let Some(entry) = self.scope.referenced_idents.get_mut(&id) {
+                if self.is_type_only_export {
+                    entry.has_type = true;
+                } else {
+                    entry.has_concrete = true;
+                }
+            }
+        }
         n.visit_children_with(self);
     }
 
@@ -1439,14 +1455,41 @@ where
     fn visit_ts_entity_name(&mut self, name: &TsEntityName, _: &dyn Node) {
         match *name {
             TsEntityName::Ident(ref i) => {
+                let entry = self.scope.referenced_idents.entry(i.to_id()).or_default();
+                entry.has_type = true;
+                if let Some(i) = &entry.maybe_dependency {
+                    let id = i.to_id();
+                    if let Some(entry) = self.scope.referenced_idents.get_mut(&id) {
+                        entry.has_type = true;
+                    }
+                }
+            }
+            TsEntityName::TsQualifiedName(ref q) => q.left.visit_with(&*q, self),
+        }
+    }
+
+    fn visit_ts_import_equals_decl(&mut self, n: &TsImportEqualsDecl, _: &dyn Node) {
+        match &n.module_ref {
+            TsModuleRef::TsEntityName(name) => {
                 let entry = self
                     .scope
                     .referenced_idents
-                    .entry((i.sym.clone(), i.span.ctxt()))
+                    .entry(n.id.to_id())
                     .or_default();
-                entry.has_type = true;
+                let mut name = name;
+                loop {
+                    match name {
+                        TsEntityName::Ident(ref i) => {
+                            entry.maybe_dependency = Some(i.clone());
+                            break;
+                        }
+                        TsEntityName::TsQualifiedName(ref q) => name = &q.left,
+                    }
+                }
+            }
+            _ => {
+                n.visit_children_with(self);
             }
-            TsEntityName::TsQualifiedName(ref q) => q.left.visit_with(&*q, self),
         }
     }
 }
@@ -2080,7 +2123,16 @@ where
                 }
 
                 ModuleItem::ModuleDecl(ModuleDecl::TsImportEquals(import)) => {
-                    if !import.is_type_only {
+                    let maybe_entry = self.scope.referenced_idents.get(&import.id.to_id());
+                    let has_concrete = if let Some(entry) = maybe_entry {
+                        entry.has_concrete
+                    } else {
+                        true
+                    };
+                    // TODO(nayeemrmn): For some reason TSC preserves `import foo = bar.baz`
+                    // when `bar.baz` is not defined, even if `foo` goes unused. We can't currently
+                    // identify that case so we strip it anyway.
+                    if !import.is_type_only && (has_concrete || import.is_export) {
                         let var = Decl::Var(VarDecl {
                             span: DUMMY_SP,
                             kind: VarDeclKind::Var,

ecmascript/transforms/typescript/tests/strip.rs

@@ -462,8 +462,6 @@ to!(module_01, "module 'foo'{ }", "");
 
 to!(declare_01, "declare var env: FOO", "");
 
-to!(import_equals, "import A = B.C", "var A = B.C;");
-
 to!(
     issue_757,
     "// test.ts
@@ -4116,6 +4114,32 @@ Foo.identifier = 5;
   "
 );
 
+to!(
+    deno_12395_import_equals_1,
+    "
+    import * as mongo from 'https://deno.land/x/mongo@v0.27.0/mod.ts';
+    import MongoClient = mongo.MongoClient;
+    const mongoClient = new MongoClient();
+    ",
+    "
+    import * as mongo from 'https://deno.land/x/mongo@v0.27.0/mod.ts';
+    var MongoClient = mongo.MongoClient;
+    const mongoClient = new MongoClient();
+    "
+);
+
+to!(
+    deno_12395_import_equals_2,
+    "
+    import * as mongo from 'https://deno.land/x/mongo@v0.27.0/mod.ts';
+    import MongoClient = mongo.MongoClient;
+    const mongoClient: MongoClient = {};
+    ",
+    "
+    const mongoClient = {};
+    "
+);
+
 #[testing::fixture("tests/fixture/**/input.ts")]
 #[testing::fixture("tests/fixture/**/input.tsx")]
 fn exec(input: PathBuf) {

tests/tsc-references/externalModules/amdImportNotAsPrimaryExpression/input.ts/es2015.1.normal/output.js

@@ -16,7 +16,6 @@ export { E11 as E1 };
 }));
 // @Filename: foo_1.ts
 const foo = require("./foo_0");
-var f = foo.M1;
 var i;
 var x = {
 };

tests/tsc-references/externalModules/amdImportNotAsPrimaryExpression/input.ts/es2015.2.minified/output.js

@@ -5,6 +5,4 @@ export class C1 {
     }
 }
 C1.s1 = !0, (E1 = E11 || (E11 = {
-}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C";
+}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0");
-const foo = require("./foo_0");
-foo.M1;

tests/tsc-references/externalModules/amdImportNotAsPrimaryExpression/input.ts/es5.1.normal/output.js

@@ -21,7 +21,6 @@ export { E11 as E1 };
 }));
 // @Filename: foo_1.ts
 var foo = require("./foo_0");
-var f = foo.M1;
 var i;
 var x = {
 };

tests/tsc-references/externalModules/amdImportNotAsPrimaryExpression/input.ts/es5.2.minified/output.js

@@ -1,4 +1,4 @@
-var E1, foo, E11, i, z, C1 = function() {
+var E1, E11, i, z, C1 = function() {
     "use strict";
     !function(instance, Constructor) {
         if (!(instance instanceof Constructor)) throw new TypeError("Cannot call a class as a function");
@@ -6,4 +6,4 @@ var E1, foo, E11, i, z, C1 = function() {
 };
 export { E11 as E1 };
 C1.s1 = !0, (E1 = E11 || (E11 = {
-}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0").M1;
+}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0");

tests/tsc-references/externalModules/commonJSImportNotAsPrimaryExpression/input.ts/es2015.1.normal/output.js

@@ -16,7 +16,6 @@ export { E11 as E1 };
 }));
 // @Filename: foo_1.ts
 const foo = require("./foo_0");
-var f = foo.M1;
 var i;
 var x = {
 };

tests/tsc-references/externalModules/commonJSImportNotAsPrimaryExpression/input.ts/es2015.2.minified/output.js

@@ -5,6 +5,4 @@ export class C1 {
     }
 }
 C1.s1 = !0, (E1 = E11 || (E11 = {
-}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C";
+}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0");
-const foo = require("./foo_0");
-foo.M1;

tests/tsc-references/externalModules/commonJSImportNotAsPrimaryExpression/input.ts/es5.1.normal/output.js

@@ -21,7 +21,6 @@ export { E11 as E1 };
 }));
 // @Filename: foo_1.ts
 var foo = require("./foo_0");
-var f = foo.M1;
 var i;
 var x = {
 };

tests/tsc-references/externalModules/commonJSImportNotAsPrimaryExpression/input.ts/es5.2.minified/output.js

@@ -1,4 +1,4 @@
-var E1, foo, E11, i, z, C1 = function() {
+var E1, E11, i, z, C1 = function() {
     "use strict";
     !function(instance, Constructor) {
         if (!(instance instanceof Constructor)) throw new TypeError("Cannot call a class as a function");
@@ -6,4 +6,4 @@ var E1, foo, E11, i, z, C1 = function() {
 };
 export { E11 as E1 };
 C1.s1 = !0, (E1 = E11 || (E11 = {
-}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0").M1;
+}))[E1.A = 0] = "A", E1[E1.B = 1] = "B", E1[E1.C = 2] = "C", require("./foo_0");

tests/tsc-references/internalModules/codeGeneration/importStatementsInterfaces/input.ts/es2015.1.normal/output.js

@@ -1,14 +1,6 @@
 // no code gen expected
-var B;
-(function(B) {
-    var a = A;
-})(B || (B = {
-}));
-// no code gen expected
 var C;
 (function(C) {
-    var a = A;
-    var b = a.inA;
     var m;
     var p;
     var p = {
@@ -21,14 +13,12 @@ var C;
 // no code gen expected
 var D;
 (function(D) {
-    var a = A;
     var p;
 })(D || (D = {
 }));
 // no code gen expected
 var E1;
 (function(E) {
-    var a = A.inA;
     function xDist(x) {
         return 0 - x.x;
     }

tests/tsc-references/internalModules/codeGeneration/importStatementsInterfaces/input.ts/es5.1.normal/output.js

@@ -1,14 +1,6 @@
 // no code gen expected
-var B;
-(function(B) {
-    var a = A;
-})(B || (B = {
-}));
-// no code gen expected
 var C;
 (function(C) {
-    var a = A;
-    var b = a.inA;
     var m;
     var p;
     var p = {
@@ -21,7 +13,6 @@ var C;
 // no code gen expected
 var D;
 (function(D) {
-    var a = A;
     var p;
 })(D || (D = {
 }));
@@ -31,7 +22,6 @@ var E1;
     var xDist = function xDist(x) {
         return 0 - x.x;
     };
-    var a = A.inA;
     E.xDist = xDist;
 })(E1 || (E1 = {
 }));

tests/tsc-references/internalModules/importDeclarations/importAliasIdentifiers/input.ts/es2015.1.normal/output.js

@@ -9,7 +9,6 @@ var moduleA1;
     moduleA.Point = Point;
 })(moduleA1 || (moduleA1 = {
 }));
-var alias = moduleA1;
 var p;
 var p;
 var p;
@@ -22,7 +21,6 @@ class clodule {
     };
 })(clodule || (clodule = {
 }));
-var clolias = clodule;
 var p;
 var p;
 var p;
@@ -39,7 +37,6 @@ function fundule() {
     };
 })(fundule || (fundule = {
 }));
-var funlias = fundule;
 var p;
 var p;
 var p;

tests/tsc-references/internalModules/importDeclarations/importAliasIdentifiers/input.ts/es5.1.normal/output.js

@@ -14,7 +14,6 @@ var moduleA1;
     moduleA.Point = Point;
 })(moduleA1 || (moduleA1 = {
 }));
-var alias = moduleA1;
 var p;
 var p;
 var p;
@@ -29,7 +28,6 @@ var clodule = function clodule() {
     };
 })(clodule || (clodule = {
 }));
-var clolias = clodule;
 var p;
 var p;
 var p;
@@ -46,7 +44,6 @@ function fundule() {
     };
 })(fundule || (fundule = {
 }));
-var funlias = fundule;
 var p;
 var p;
 var p;

tests/tsc-references/internalModules/importDeclarations/invalidImportAliasIdentifiers/input.ts/es2015.1.normal/output.js

@@ -1,15 +1,11 @@
 // none of these should work, since non are actually modules
 var V = 12;
-var v = V;
 class C {
 }
-var c = C;
 var E1;
 (function(E) {
     E[E["Red"] = 0] = "Red";
     E[E["Blue"] = 1] = "Blue";
 })(E1 || (E1 = {
 }));
-var e = E1;
-var i = I;
 export { };

tests/tsc-references/internalModules/importDeclarations/invalidImportAliasIdentifiers/input.ts/es5.1.normal/output.js

@@ -5,18 +5,14 @@ function _classCallCheck(instance, Constructor) {
 }
 // none of these should work, since non are actually modules
 var V = 12;
-var v = V;
 var C = function C() {
     "use strict";
     _classCallCheck(this, C);
 };
-var c = C;
 var E1;
 (function(E) {
     E[E["Red"] = 0] = "Red";
     E[E["Blue"] = 1] = "Blue";
 })(E1 || (E1 = {
 }));
-var e = E1;
-var i = I;
 export { };

tests/tsc-references/internalModules/importDeclarations/shadowedInternalModule/input.ts/es2015.1.normal/output.js

@@ -13,7 +13,6 @@ var B;
         x: 0,
         y: 0
     };
-    var Point = A;
 })(B || (B = {
 }));
 var X1;
@@ -25,7 +24,6 @@ var X1;
 }));
 var Z;
 (function(Z) {
-    var Y = X1.Y;
     var Y = 12;
 })(Z || (Z = {
 }));

tests/tsc-references/internalModules/importDeclarations/shadowedInternalModule/input.ts/es2015.2.minified/output.js

@@ -1,9 +1,8 @@
-var A, X, Z;
+var A, X;
 (A || (A = {
 })).Point = {
     x: 0,
     y: 0
 }, (X || (X = {
 })).Y = class {
-}, Z || (Z = {
+};
-}), X.Y;

tests/tsc-references/internalModules/importDeclarations/shadowedInternalModule/input.ts/es5.1.normal/output.js

@@ -18,7 +18,6 @@ var B;
         x: 0,
         y: 0
     };
-    var Point = A;
 })(B || (B = {
 }));
 var X1;
@@ -32,7 +31,6 @@ var X1;
 }));
 var Z;
 (function(Z) {
-    var Y = X1.Y;
     var Y = 12;
 })(Z || (Z = {
 }));

tests/tsc-references/internalModules/importDeclarations/shadowedInternalModule/input.ts/es5.2.minified/output.js

@@ -1,4 +1,4 @@
-var A, X1, Z;
+var A, X1;
 (A || (A = {
 })).Point = {
     x: 0,
@@ -12,5 +12,4 @@ var A, X1, Z;
     };
     X.Y = Y;
 })(X1 || (X1 = {
-})), Z || (Z = {
+}));
-}), X1.Y;

tests/tsc-references/parser/ecmascript5/parserImportDeclaration1/input.ts/es2015.1.normal/output.js

@@ -1,2 +1 @@
-var TypeScript = TypeScriptServices.TypeScript;
 export { };

tests/tsc-references/parser/ecmascript5/parserImportDeclaration1/input.ts/es5.1.normal/output.js

@@ -1,2 +1 @@
-var TypeScript = TypeScriptServices.TypeScript;
 export { };

tests/tsc-references/scanner/ecmascript5/scannerImportDeclaration1/input.ts/es2015.1.normal/output.js

@@ -1,2 +1 @@
-var TypeScript = TypeScriptServices.TypeScript;
 export { };

tests/tsc-references/scanner/ecmascript5/scannerImportDeclaration1/input.ts/es5.1.normal/output.js

@@ -1,2 +1 @@
-var TypeScript = TypeScriptServices.TypeScript;
 export { };

tests/tsc-references/types/specifyingTypes/typeQueries/typeofANonExportedType/input.ts/es2015.1.normal/output.js

@@ -25,7 +25,6 @@ var M1;
 }));
 export var r6;
 export var r7;
-var Z = M1;
 export var r8;
 export var r9;
 var E1;

tests/tsc-references/types/specifyingTypes/typeQueries/typeofANonExportedType/input.ts/es5.1.normal/output.js

@@ -34,7 +34,6 @@ var M1;
 }));
 export var r6;
 export var r7;
-var Z = M1;
 export var r8;
 export var r9;
 var E1;