Fix: Arrow function body should be ObjectExpression (fixes #331) (#334)

Author: soda0289

lib/convert.js

@@ -606,8 +606,18 @@ module.exports = function convert(config) {
 
         case SyntaxKind.ObjectLiteralExpression: {
 
-            const objectAssignNode = nodeUtils.findAncestorOfKind(node, SyntaxKind.BinaryExpression);
-            let objectIsInAssignment;
+            const ancestorNode = nodeUtils.findFirstMatchingAncestor(
+                node,
+                parentNode =>
+                    (parentNode.kind === SyntaxKind.BinaryExpression || parentNode.kind === SyntaxKind.ArrowFunction)
+                );
+            const objectAssignNode = (
+                ancestorNode &&
+                ancestorNode.kind === SyntaxKind.BinaryExpression &&
+                ancestorNode.operatorToken.kind === SyntaxKind.FirstAssignment
+            ) ? ancestorNode : null;
+
+            let objectIsInAssignment = false;
 
             if (objectAssignNode) {
                 if (objectAssignNode.left === node) {

lib/node-utils.js

@@ -121,22 +121,6 @@ function findFirstMatchingChild(node, sourceFile, predicate) {
     return undefined;
 }
 
-/**
- * Find the first matching ancestor based on the given predicate function.
- * @param {TSNode} node The current TSNode
- * @param {Function} predicate The predicate function to apply to each checked ancestor
- * @returns {TSNode|undefined} a matching parent TSNode
- */
-function findFirstMatchingAncestor(node, predicate) {
-    while (node) {
-        if (predicate(node)) {
-            return node;
-        }
-        node = node.parent;
-    }
-    return undefined;
-}
-
 /**
  * Returns true if the given TSNode is a let variable declaration
  * @param {TSNode} node The TSNode
@@ -187,6 +171,7 @@ module.exports = {
     hasStaticModifierFlag,
     findNextToken,
     findChildOfKind,
+    findFirstMatchingAncestor,
     findAncestorOfKind,
     hasJSXAncestor,
     unescapeIdentifier,
@@ -417,6 +402,22 @@ function findChildOfKind(node, kind, sourceFile) {
     return findFirstMatchingChild(node, sourceFile, child => child.kind === kind);
 }
 
+/**
+ * Find the first matching ancestor based on the given predicate function.
+ * @param {TSNode} node The current TSNode
+ * @param {Function} predicate The predicate function to apply to each checked ancestor
+ * @returns {TSNode|undefined} a matching parent TSNode
+ */
+function findFirstMatchingAncestor(node, predicate) {
+    while (node) {
+        if (predicate(node)) {
+            return node;
+        }
+        node = node.parent;
+    }
+    return undefined;
+}
+
 /**
  * Finds the first parent TSNode which mastches the given kind
  * @param {TSNode} node The current TSNode
@@ -427,6 +428,7 @@ function findAncestorOfKind(node, kind) {
     return findFirstMatchingAncestor(node, parent => parent.kind === kind);
 }
 
+
 /**
  * Returns true if a given TSNode has a JSX token within its hierarchy
  * @param  {TSNode} node TSNode to be checked

tests/fixtures/ecma-features/arrowFunctions/basic-in-binary-expression.src.js

@@ -0,0 +1,5 @@
+(a => ({})) + 1;
+(a => ({})) = 1;
+((a => ({})) + 1);
+((a => ({})) = 1);
+