Fix: Ensure modifiers are applied to enums (fixes #365) (#366)

Author: JamesHenry

lib/ast-node-types.js

@@ -101,9 +101,11 @@ module.exports = {
      * TS-prefixed nodes
      */
     TSAbstractClassProperty: "TSAbstractClassProperty",
+    TSAbstractKeyword: "TSAbstractKeyword",
     TSAbstractMethodDefinition: "TSAbstractMethodDefinition",
     TSAnyKeyword: "TSAnyKeyword",
     TSArrayType: "TSArrayType",
+    TSAsyncKeyword: "TSAsyncKeyword",
     TSBooleanKeyword: "TSBooleanKeyword",
     TSConstructorType: "TSConstructorType",
     TSConstructSignature: "TSConstructSignature",
@@ -125,9 +127,14 @@ module.exports = {
     TSNumberKeyword: "TSNumberKeyword",
     TSObjectKeyword: "TSObjectKeyword",
     TSParameterProperty: "TSParameterProperty",
+    TSPrivateKeyword: "TSPrivateKeyword",
     TSPropertySignature: "TSPropertySignature",
+    TSProtectedKeyword: "TSProtectedKeyword",
+    TSPublicKeyword: "TSPublicKeyword",
     TSQualifiedName: "TSQualifiedName",
     TSQuestionToken: "TSQuestionToken",
+    TSReadonlyKeyword: "TSReadonlyKeyword",
+    TSStaticKeyword: "TSStaticKeyword",
     TSStringKeyword: "TSStringKeyword",
     TSTypeLiteral: "TSTypeLiteral",
     TSTypePredicate: "TSTypePredicate",

lib/convert.js

@@ -330,6 +330,52 @@ module.exports = function convert(config) {
         return tagNameToken;
     }
 
+    /**
+     * Applies the given TS modifiers to the given result object.
+     * @param {TSNode[]} modifiers original TSNodes from the node.modifiers array
+     * @returns {void} (the current result object will be mutated)
+     */
+    function applyModifiersToResult(modifiers) {
+        if (!modifiers || !modifiers.length) {
+            return;
+        }
+        /**
+         * Some modifiers are explicitly handled by applying them as
+         * boolean values on the result node. As well as adding them
+         * to the result, we remove them from the array, so that they
+         * are not handled twice.
+         */
+        const handledModifierIndices = {};
+        for (let i = 0; i < modifiers.length; i++) {
+            const modifier = modifiers[i];
+            switch (modifier.kind) {
+                /**
+                 * Ignore ExportKeyword and DefaultKeyword, they are handled
+                 * via the fixExports utility function
+                 */
+                case SyntaxKind.ExportKeyword:
+                case SyntaxKind.DefaultKeyword:
+                    handledModifierIndices[i] = true;
+                    break;
+                case SyntaxKind.ConstKeyword:
+                    result.const = true;
+                    handledModifierIndices[i] = true;
+                    break;
+                default:
+            }
+        }
+        /**
+         * If there are still valid modifiers available which have
+         * not been explicitly handled above, we just convert and
+         * add the modifiers array to the result node.
+         */
+        const remainingModifiers = modifiers.filter((_, i) => !handledModifierIndices[i]);
+        if (!remainingModifiers || !remainingModifiers.length) {
+            return;
+        }
+        result.modifiers = remainingModifiers.map(convertChild);
+    }
+
     /**
      * The core of the conversion logic:
      * Identify and convert each relevant TypeScript SyntaxKind
@@ -2000,7 +2046,9 @@ module.exports = function convert(config) {
                 id: convertChild(node.name),
                 members: node.members.map(convertChild)
             });
-            // check for exports
+            // apply modifiers first...
+            applyModifiersToResult(node.modifiers);
+            // ...then check for exports
             result = nodeUtils.fixExports(node, result, ast);
             /**
              * Semantically, decorators are not allowed on enum declarations,

tests/ast-alignment/spec.js

@@ -422,6 +422,7 @@ const fixturePatternsToTest = [
     "typescript/basics/async-function-with-var-declaration.src.ts",
     "typescript/basics/function-with-await.src.ts",
     "typescript/errorRecovery/class-extends-empty-implements.src.ts",
+    "typescript/basics/const-enum.src.ts",
 
     {
         pattern: "typescript/basics/export-named-enum.src.ts",
@@ -435,6 +436,7 @@ const fixturePatternsToTest = [
     // "typescript/errorRecovery/class-empty-extends.src.ts", // babylon parse errors
     // "typescript/errorRecovery/decorator-on-enum-declaration.src.ts", // babylon parse errors
     // "typescript/errorRecovery/interface-property-modifiers.src.ts", // babylon parse errors
+    // "typescript/errorRecovery/enum-with-keywords.src.ts" // babylon parse errors
 
     /**
      * Other babylon parse errors. TODO: Need to coordinate with TS Team.

tests/fixtures/typescript/basics/const-enum.src.ts

@@ -0,0 +1,4 @@
+const enum Foo {
+    foo = 1,
+    bar
+}

tests/fixtures/typescript/errorRecovery/enum-with-keywords.src.ts

@@ -0,0 +1 @@
+export private public protected static readonly abstract async enum X {}