Exclude completions of binding pattern variable initializers (#52723)

Co-authored-by: Nathan Shively-Sanders <[email protected]>

Author: zardoy

Diff for: src/services/completions.ts

@@ -2745,8 +2745,14 @@ export function getCompletionEntriesFromSymbols(
             }
             // Filter out variables from their own initializers
             // `const a = /* no 'a' here */`
-            if (tryCast(closestSymbolDeclaration, isVariableDeclaration) && symbol.valueDeclaration === closestSymbolDeclaration) {
-                return false;
+            if (closestSymbolDeclaration && tryCast(closestSymbolDeclaration, isVariableDeclaration)) {
+                if (symbol.valueDeclaration === closestSymbolDeclaration) {
+                    return false;
+                }
+                // const { a } = /* no 'a' here */;
+                if (isBindingPattern(closestSymbolDeclaration.name) && closestSymbolDeclaration.name.elements.some(e => e === symbol.valueDeclaration)) {
+                    return false;
+                }
             }
 
             // Filter out current and latter parameters from defaults

Diff for: tests/cases/fourslash/completionListWithoutVariableinitializer.ts

@@ -9,6 +9,10 @@
 //// const fn = (p = /*7*/) => {}
 //// const { g, h = /*8*/ } = { ... }
 //// const [ g1, h1 = /*9*/ ] = [ ... ]
+//// const { a1 } = a/*10*/;
+//// const { a2 } = fn({a: a/*11*/});
+//// const [ a3 ] = a/*12*/;
+//// const [ a4 ] = fn([a/*13*/]);
 
 verify.completions({
     marker: ["1"],
@@ -58,3 +62,26 @@ verify.completions({
     marker: ["9"],
     includes: ["a", "b", "c", "d", "e", "fn"],
 });
+
+verify.completions({
+    marker: ["10"],
+    excludes: ["a1"],
+    isNewIdentifierLocation: true,
+});
+
+verify.completions({
+    marker: ["11"],
+    excludes: ["a2"],
+});
+
+verify.completions({
+    marker: ["12"],
+    excludes: ["a3"],
+    isNewIdentifierLocation: true,
+});
+
+verify.completions({
+    marker: ["13"],
+    excludes: ["a4"],
+    isNewIdentifierLocation: true,
+});