Enable substitution for object literal shorthand property assignments in the system transform (#21106)

Author: weswigham

src/compiler/transformers/module/system.ts

@@ -24,6 +24,7 @@ namespace ts {
         context.onSubstituteNode = onSubstituteNode;
         context.onEmitNode = onEmitNode;
         context.enableSubstitution(SyntaxKind.Identifier); // Substitutes expression identifiers for imported symbols.
+        context.enableSubstitution(SyntaxKind.ShorthandPropertyAssignment); // Substitutes expression identifiers for imported symbols
         context.enableSubstitution(SyntaxKind.BinaryExpression); // Substitutes assignments to exported symbols.
         context.enableSubstitution(SyntaxKind.PrefixUnaryExpression); // Substitutes updates to exported symbols.
         context.enableSubstitution(SyntaxKind.PostfixUnaryExpression); // Substitutes updates to exported symbols.
@@ -1625,10 +1626,64 @@ namespace ts {
             if (hint === EmitHint.Expression) {
                 return substituteExpression(<Expression>node);
             }
+            else if (hint === EmitHint.Unspecified) {
+                return substituteUnspecified(node);
+            }
 
             return node;
         }
 
+        /**
+         * Substitute the node, if necessary.
+         *
+         * @param node The node to substitute.
+         */
+        function substituteUnspecified(node: Node) {
+            switch (node.kind) {
+                case SyntaxKind.ShorthandPropertyAssignment:
+                    return substituteShorthandPropertyAssignment(<ShorthandPropertyAssignment>node);
+            }
+            return node;
+        }
+        /**
+         * Substitution for a ShorthandPropertyAssignment whose name that may contain an imported or exported symbol.
+         *
+         * @param node The node to substitute.
+         */
+        function substituteShorthandPropertyAssignment(node: ShorthandPropertyAssignment) {
+            const name = node.name;
+            if (!isGeneratedIdentifier(name) && !isLocalName(name)) {
+                const importDeclaration = resolver.getReferencedImportDeclaration(name);
+                if (importDeclaration) {
+                    if (isImportClause(importDeclaration)) {
+                        return setTextRange(
+                            createPropertyAssignment(
+                                getSynthesizedClone(name),
+                                createPropertyAccess(
+                                    getGeneratedNameForNode(importDeclaration.parent),
+                                    createIdentifier("default")
+                                )
+                            ),
+                            /*location*/ node
+                        );
+                    }
+                    else if (isImportSpecifier(importDeclaration)) {
+                        return setTextRange(
+                            createPropertyAssignment(
+                                getSynthesizedClone(name),
+                                createPropertyAccess(
+                                    getGeneratedNameForNode(importDeclaration.parent.parent.parent),
+                                    getSynthesizedClone(importDeclaration.propertyName || importDeclaration.name)
+                                ),
+                            ),
+                            /*location*/ node
+                        );
+                    }
+                }
+            }
+            return node;
+        }
+
         /**
          * Substitute the expression, if necessary.
          *

tests/baselines/reference/systemObjectShorthandRename.js

@@ -0,0 +1,44 @@
+//// [tests/cases/compiler/systemObjectShorthandRename.ts] ////
+
+//// [x.ts]
+export const x = 'X'
+//// [index.ts]
+import {x} from './x.js'
+
+const x2 = {x}
+const a = {x2}
+
+const x3 = x
+const b = {x3}
+
+//// [x.js]
+System.register([], function (exports_1, context_1) {
+    "use strict";
+    var __moduleName = context_1 && context_1.id;
+    var x;
+    return {
+        setters: [],
+        execute: function () {
+            exports_1("x", x = 'X');
+        }
+    };
+});
+//// [index.js]
+System.register(["./x.js"], function (exports_1, context_1) {
+    "use strict";
+    var __moduleName = context_1 && context_1.id;
+    var x_js_1, x2, a, x3, b;
+    return {
+        setters: [
+            function (x_js_1_1) {
+                x_js_1 = x_js_1_1;
+            }
+        ],
+        execute: function () {
+            x2 = { x: x_js_1.x };
+            a = { x2 };
+            x3 = x_js_1.x;
+            b = { x3 };
+        }
+    };
+});

tests/baselines/reference/systemObjectShorthandRename.symbols

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/x.ts ===
+export const x = 'X'
+>x : Symbol(x, Decl(x.ts, 0, 12))
+
+=== tests/cases/compiler/index.ts ===
+import {x} from './x.js'
+>x : Symbol(x, Decl(index.ts, 0, 8))
+
+const x2 = {x}
+>x2 : Symbol(x2, Decl(index.ts, 2, 5))
+>x : Symbol(x, Decl(index.ts, 2, 12))
+
+const a = {x2}
+>a : Symbol(a, Decl(index.ts, 3, 5))
+>x2 : Symbol(x2, Decl(index.ts, 3, 11))
+
+const x3 = x
+>x3 : Symbol(x3, Decl(index.ts, 5, 5))
+>x : Symbol(x, Decl(index.ts, 0, 8))
+
+const b = {x3}
+>b : Symbol(b, Decl(index.ts, 6, 5))
+>x3 : Symbol(x3, Decl(index.ts, 6, 11))
+

tests/baselines/reference/systemObjectShorthandRename.types

@@ -0,0 +1,28 @@
+=== tests/cases/compiler/x.ts ===
+export const x = 'X'
+>x : "X"
+>'X' : "X"
+
+=== tests/cases/compiler/index.ts ===
+import {x} from './x.js'
+>x : "X"
+
+const x2 = {x}
+>x2 : { x: string; }
+>{x} : { x: string; }
+>x : string
+
+const a = {x2}
+>a : { x2: { x: string; }; }
+>{x2} : { x2: { x: string; }; }
+>x2 : { x: string; }
+
+const x3 = x
+>x3 : "X"
+>x : "X"
+
+const b = {x3}
+>b : { x3: string; }
+>{x3} : { x3: string; }
+>x3 : string
+

tests/cases/compiler/systemObjectShorthandRename.ts

@@ -0,0 +1,12 @@
+// @module: system
+// @target: es2015
+// @filename: x.ts
+export const x = 'X'
+// @filename: index.ts
+import {x} from './x.js'
+
+const x2 = {x}
+const a = {x2}
+
+const x3 = x
+const b = {x3}