Cleaned up emit of enum declaration

Author: rbuckton

src/compiler/transformers/module/module.ts

@@ -792,12 +792,6 @@ namespace ts {
         function visitExpressionStatementForEnumOrNamespaceDeclaration(node: ExpressionStatement, original: EnumDeclaration | ModuleDeclaration): VisitResult<Statement> {
             const statements: Statement[] = [node];
 
-            // Preserve old behavior for enums in which a variable statement is emitted after the body itself.
-            if (hasModifier(original, ModifierFlags.Export) &&
-                original.kind === SyntaxKind.EnumDeclaration &&
-                isFirstDeclarationOfKind(original, SyntaxKind.EnumDeclaration)) {
-                addVarForExportedEnumOrNamespaceDeclaration(statements, original);
-            }
 
             addExportMemberAssignments(statements, <Identifier>original.name);
 

src/compiler/transformers/module/system.ts

@@ -692,12 +692,6 @@ namespace ts {
             const originalNode = getOriginalNode(node);
             if ((originalNode.kind === SyntaxKind.ModuleDeclaration || originalNode.kind === SyntaxKind.EnumDeclaration) && hasModifier(originalNode, ModifierFlags.Export)) {
                 const name = getDeclarationName(<ModuleDeclaration | EnumDeclaration>originalNode);
-                // We only need to hoistVariableDeclaration for EnumDeclaration
-                // as ModuleDeclaration is already hoisted when the transformer call visitVariableStatement
-                // which then call transformsVariable for each declaration in declarationList
-                if (originalNode.kind === SyntaxKind.EnumDeclaration) {
-                    hoistVariableDeclaration(name);
-                }
                 return [
                     node,
                     createExportStatement(name, name)
@@ -849,7 +843,7 @@ namespace ts {
                 visitNode(node.statement, visitNestedNode, isStatement, /*optional*/ false, liftToBlock),
                 node.expression
             );
-            }
+        }
 
         /**
          * Visits the body of a WhileStatement to hoist declarations.
@@ -862,7 +856,7 @@ namespace ts {
                 node.expression,
                 visitNode(node.statement, visitNestedNode, isStatement, /*optional*/ false, liftToBlock)
             );
-            }
+        }
 
         /**
          * Visits the body of a LabeledStatement to hoist declarations.

src/compiler/transformers/ts.ts

@@ -2517,29 +2517,6 @@ namespace ts {
                 || compilerOptions.isolatedModules;
         }
 
-        function shouldEmitVarForEnumDeclaration(node: EnumDeclaration | ModuleDeclaration) {
-            return isFirstEmittedDeclarationInScope(node)
-                && (!hasModifier(node, ModifierFlags.Export)
-                    || isES6ExportedDeclaration(node));
-        }
-
-
-        /*
-         * Adds a trailing VariableStatement for an enum or module declaration.
-         */
-        function addVarForEnumExportedFromNamespace(statements: Statement[], node: EnumDeclaration | ModuleDeclaration) {
-            const statement = createVariableStatement(
-                /*modifiers*/ undefined,
-                [createVariableDeclaration(
-                    getDeclarationName(node),
-                    /*type*/ undefined,
-                    getExportName(node)
-                )]
-            );
-            setSourceMapRange(statement, node);
-            statements.push(statement);
-        }
-
         /**
          * Visits an enum declaration.
          *
@@ -2562,7 +2539,7 @@ namespace ts {
             // a leading variable declaration, we should not emit leading comments for the
             // enum body.
             recordEmittedDeclarationInScope(node);
-            if (shouldEmitVarForEnumDeclaration(node)) {
+            if (isFirstEmittedDeclarationInScope(node)) {
                 addVarForEnumOrModuleDeclaration(statements, node);
 
                 // We should still emit the comments if we are emitting a system module.
@@ -2580,6 +2557,25 @@ namespace ts {
             // `exportName` is the expression used within this node's container for any exported references.
             const exportName = getExportName(node);
 
+            //  x || (x = {})
+            //  exports.x || (exports.x = {})
+            let moduleArg =
+                createLogicalOr(
+                    exportName,
+                    createAssignment(
+                        exportName,
+                        createObjectLiteral()
+                    )
+                );
+
+            if (hasModifier(node, ModifierFlags.Export) && !isES6ExportedDeclaration(node)) {
+                // `localName` is the expression used within this node's containing scope for any local references.
+                const localName = getLocalName(node);
+
+                //  x = (exports.x || (exports.x = {}))
+                moduleArg = createAssignment(localName, moduleArg);
+            }
+
             //  (function (x) {
             //      x[x["y"] = 0] = "y";
             //      ...
@@ -2596,25 +2592,14 @@ namespace ts {
                         transformEnumBody(node, containerName)
                     ),
                     /*typeArguments*/ undefined,
-                    [createLogicalOr(
-                        exportName,
-                        createAssignment(
-                            exportName,
-                            createObjectLiteral()
-                        )
-                    )]
+                    [moduleArg]
                 ),
                 /*location*/ node
             );
 
             setOriginalNode(enumStatement, node);
             setEmitFlags(enumStatement, emitFlags);
             statements.push(enumStatement);
-
-            if (isNamespaceExport(node)) {
-                addVarForEnumExportedFromNamespace(statements, node);
-            }
-
             return statements;
         }
 
@@ -2739,10 +2724,6 @@ namespace ts {
             return false;
         }
 
-        function shouldEmitVarForModuleDeclaration(node: ModuleDeclaration) {
-            return isFirstEmittedDeclarationInScope(node);
-        }
-
         /**
          * Adds a leading VariableStatement for a enum or module declaration.
          */
@@ -2817,7 +2798,7 @@ namespace ts {
             // a leading variable declaration, we should not emit leading comments for the
             // module body.
             recordEmittedDeclarationInScope(node);
-            if (shouldEmitVarForModuleDeclaration(node)) {
+            if (isFirstEmittedDeclarationInScope(node)) {
                 addVarForEnumOrModuleDeclaration(statements, node);
                 // We should still emit the comments if we are emitting a system module.
                 if (moduleKind !== ModuleKind.System || currentScope !== currentSourceFile) {

tests/baselines/reference/ModuleWithExportedAndNonExportedEnums.js

@@ -14,11 +14,11 @@ var b = A.Day.Monday;
 //// [ModuleWithExportedAndNonExportedEnums.js]
 var A;
 (function (A) {
+    var Color;
     (function (Color) {
         Color[Color["Red"] = 0] = "Red";
         Color[Color["Blue"] = 1] = "Blue";
-    })(A.Color || (A.Color = {}));
-    var Color = A.Color;
+    })(Color = A.Color || (A.Color = {}));
     var Day;
     (function (Day) {
         Day[Day["Monday"] = 0] = "Monday";

tests/baselines/reference/amdImportAsPrimaryExpression.js

@@ -15,12 +15,12 @@ if(foo.E1.A === 0){
 //// [foo_0.js]
 define(["require", "exports"], function (require, exports) {
     "use strict";
+    var E1;
     (function (E1) {
         E1[E1["A"] = 0] = "A";
         E1[E1["B"] = 1] = "B";
         E1[E1["C"] = 2] = "C";
-    })(exports.E1 || (exports.E1 = {}));
-    var E1 = exports.E1;
+    })(E1 = exports.E1 || (exports.E1 = {}));
 });
 //// [foo_1.js]
 define(["require", "exports", "./foo_0"], function (require, exports, foo) {

tests/baselines/reference/amdImportNotAsPrimaryExpression.js

@@ -42,12 +42,12 @@ define(["require", "exports"], function (require, exports) {
     }());
     exports.C1 = C1;
     C1.s1 = true;
+    var E1;
     (function (E1) {
         E1[E1["A"] = 0] = "A";
         E1[E1["B"] = 1] = "B";
         E1[E1["C"] = 2] = "C";
-    })(exports.E1 || (exports.E1 = {}));
-    var E1 = exports.E1;
+    })(E1 = exports.E1 || (exports.E1 = {}));
 });
 //// [foo_1.js]
 define(["require", "exports"], function (require, exports) {

tests/baselines/reference/collisionExportsRequireAndEnum.js

@@ -63,16 +63,16 @@ module m4 {
 //// [collisionExportsRequireAndEnum_externalmodule.js]
 define(["require", "exports"], function (require, exports) {
     "use strict";
+    var require;
     (function (require) {
         require[require["_thisVal1"] = 0] = "_thisVal1";
         require[require["_thisVal2"] = 1] = "_thisVal2";
-    })(exports.require || (exports.require = {}));
-    var require = exports.require;
+    })(require = exports.require || (exports.require = {}));
+    var exports;
     (function (exports) {
         exports[exports["_thisVal1"] = 0] = "_thisVal1";
         exports[exports["_thisVal2"] = 1] = "_thisVal2";
-    })(exports.exports || (exports.exports = {}));
-    var exports = exports.exports;
+    })(exports = exports.exports || (exports.exports = {}));
     var m1;
     (function (m1) {
         var require;
@@ -88,16 +88,16 @@ define(["require", "exports"], function (require, exports) {
     })(m1 || (m1 = {}));
     var m2;
     (function (m2) {
+        var require;
         (function (require) {
             require[require["_thisVal1"] = 0] = "_thisVal1";
             require[require["_thisVal2"] = 1] = "_thisVal2";
-        })(m2.require || (m2.require = {}));
-        var require = m2.require;
+        })(require = m2.require || (m2.require = {}));
+        var exports;
         (function (exports) {
             exports[exports["_thisVal1"] = 0] = "_thisVal1";
             exports[exports["_thisVal2"] = 1] = "_thisVal2";
-        })(m2.exports || (m2.exports = {}));
-        var exports = m2.exports;
+        })(exports = m2.exports || (m2.exports = {}));
     })(m2 || (m2 = {}));
 });
 //// [collisionExportsRequireAndEnum_globalFile.js]
@@ -126,14 +126,14 @@ var m3;
 })(m3 || (m3 = {}));
 var m4;
 (function (m4) {
+    var require;
     (function (require) {
         require[require["_thisVal1"] = 0] = "_thisVal1";
         require[require["_thisVal2"] = 1] = "_thisVal2";
-    })(m4.require || (m4.require = {}));
-    var require = m4.require;
+    })(require = m4.require || (m4.require = {}));
+    var exports;
     (function (exports) {
         exports[exports["_thisVal1"] = 0] = "_thisVal1";
         exports[exports["_thisVal2"] = 1] = "_thisVal2";
-    })(m4.exports || (m4.exports = {}));
-    var exports = m4.exports;
+    })(exports = m4.exports || (m4.exports = {}));
 })(m4 || (m4 = {}));

tests/baselines/reference/commentOnExportEnumDeclaration.js

@@ -11,9 +11,9 @@ export enum Color {
 /**
  * comment
  */
+var Color;
 (function (Color) {
     Color[Color["r"] = 0] = "r";
     Color[Color["g"] = 1] = "g";
     Color[Color["b"] = 2] = "b";
-})(exports.Color || (exports.Color = {}));
-var Color = exports.Color;
+})(Color = exports.Color || (exports.Color = {}));

tests/baselines/reference/commonJSImportNotAsPrimaryExpression.js

@@ -41,12 +41,12 @@ var C1 = (function () {
 }());
 exports.C1 = C1;
 C1.s1 = true;
+var E1;
 (function (E1) {
     E1[E1["A"] = 0] = "A";
     E1[E1["B"] = 1] = "B";
     E1[E1["C"] = 2] = "C";
-})(exports.E1 || (exports.E1 = {}));
-var E1 = exports.E1;
+})(E1 = exports.E1 || (exports.E1 = {}));
 //// [foo_1.js]
 "use strict";
 var i;

tests/baselines/reference/declFileTypeofInAnonymousType.js

@@ -31,12 +31,12 @@ var m1;
         return c;
     }());
     m1.c = c;
+    var e;
     (function (e) {
         e[e["weekday"] = 0] = "weekday";
         e[e["weekend"] = 1] = "weekend";
         e[e["holiday"] = 2] = "holiday";
-    })(m1.e || (m1.e = {}));
-    var e = m1.e;
+    })(e = m1.e || (m1.e = {}));
 })(m1 || (m1 = {}));
 var a;
 var b = {