Revert "fix: invalid operator in operator-assignment messages (eslint#15759)"

This reverts commit 1c9970a.

Author: srijan-deepsource

lib/rules/operator-assignment.js

@@ -76,8 +76,8 @@ module.exports = {
 
         fixable: "code",
         messages: {
-            replaced: "Assignment (=) can be replaced with operator assignment ({{operator}}).",
-            unexpected: "Unexpected operator assignment ({{operator}}) shorthand."
+            replaced: "Assignment (=) can be replaced with operator assignment ({{operator}}=).",
+            unexpected: "Unexpected operator assignment ({{operator}}=) shorthand."
         }
     },
 
@@ -109,13 +109,11 @@ module.exports = {
             const operator = expr.operator;
 
             if (isCommutativeOperatorWithShorthand(operator) || isNonCommutativeOperatorWithShorthand(operator)) {
-                const replacementOperator = `${operator}=`;
-
                 if (astUtils.isSameReference(left, expr.left, true)) {
                     context.report({
                         node,
                         messageId: "replaced",
-                        data: { operator: replacementOperator },
+                        data: { operator },
                         fix(fixer) {
                             if (canBeFixed(left) && canBeFixed(expr.left)) {
                                 const equalsToken = getOperatorToken(node);
@@ -128,7 +126,7 @@ module.exports = {
                                     return null;
                                 }
 
-                                return fixer.replaceText(node, `${leftText}${replacementOperator}${rightText}`);
+                                return fixer.replaceText(node, `${leftText}${expr.operator}=${rightText}`);
                             }
                             return null;
                         }
@@ -143,7 +141,7 @@ module.exports = {
                     context.report({
                         node,
                         messageId: "replaced",
-                        data: { operator: replacementOperator }
+                        data: { operator }
                     });
                 }
             }