feat(54190): Convert to template string quick fix not available in assignment expressions (#54210)

Author: a-tarasyuk

src/services/refactors/convertStringOrTemplateLiteral.ts

@@ -122,7 +122,7 @@ function getEditsForToTemplateLiteral(context: RefactorContext, node: Node) {
 }
 
 function isNotEqualsOperator(node: BinaryExpression) {
-    return node.operatorToken.kind !== SyntaxKind.EqualsToken;
+    return !(node.operatorToken.kind === SyntaxKind.EqualsToken || node.operatorToken.kind === SyntaxKind.PlusEqualsToken);
 }
 
 function getParentBinaryExpression(expr: Node) {

…rTemplateLiteral_ToTemplateBinaryExpr.ts …TemplateLiteral_ToTemplateBinaryExpr1.tstests/cases/fourslash/refactorConvertStringOrTemplateLiteral_ToTemplateBinaryExpr.ts renamed to tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_ToTemplateBinaryExpr1.ts tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_ToTemplateBinaryExpr.ts renamed to tests/cases/fourslash/refactorConvertStringOrTemplateLiteral_ToTemplateBinaryExpr1.ts

@@ -0,0 +1,17 @@
+/// <reference path='fourslash.ts' />
+
+////let b = 1;
+////let a = '';
+////a += /*a*/'foo' + b/*b*/;
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert to template string",
+    actionName: "Convert to template string",
+    actionDescription: ts.Diagnostics.Convert_to_template_string.message,
+    newContent: [
+        "let b = 1;",
+        "let a = '';",
+        "a += `foo${b}`;"
+    ].join("\n")
+});