Support navTo for special assignment kinds (#18154)

* Support navTo for special assignment kinds

* Return ScriptElementKind.unknown

Author: Andy

src/compiler/core.ts

@@ -2628,4 +2628,6 @@ namespace ts {
     export function and<T>(f: (arg: T) => boolean, g: (arg: T) => boolean) {
         return (arg: T) => f(arg) && g(arg);
     }
+
+    export function assertTypeIsNever(_: never): void {}
 }

src/services/services.ts

@@ -722,6 +722,12 @@ namespace ts {
                         }
                         break;
 
+                    case SyntaxKind.BinaryExpression:
+                        if (getSpecialPropertyAssignmentKind(node as BinaryExpression) !== SpecialPropertyAssignmentKind.None) {
+                           addDeclaration(node as BinaryExpression);
+                        }
+                        // falls through
+
                     default:
                         forEachChild(node, visit);
                 }

src/services/utilities.ts

@@ -343,6 +343,28 @@ namespace ts {
                 return ScriptElementKind.alias;
             case SyntaxKind.JSDocTypedefTag:
                 return ScriptElementKind.typeElement;
+            case SyntaxKind.BinaryExpression:
+                const kind = getSpecialPropertyAssignmentKind(node as BinaryExpression);
+                const { right } = node as BinaryExpression;
+                switch (kind) {
+                    case SpecialPropertyAssignmentKind.None:
+                        return ScriptElementKind.unknown;
+                    case SpecialPropertyAssignmentKind.ExportsProperty:
+                    case SpecialPropertyAssignmentKind.ModuleExports:
+                        const rightKind = getNodeKind(right);
+                        return rightKind === ScriptElementKind.unknown ? ScriptElementKind.constElement : rightKind;
+                    case SpecialPropertyAssignmentKind.PrototypeProperty:
+                        return ScriptElementKind.memberFunctionElement; // instance method
+                    case SpecialPropertyAssignmentKind.ThisProperty:
+                        return ScriptElementKind.memberVariableElement; // property
+                    case SpecialPropertyAssignmentKind.Property:
+                        // static method / property
+                        return isFunctionExpression(right) ? ScriptElementKind.memberFunctionElement : ScriptElementKind.memberVariableElement;
+                    default: {
+                        assertTypeIsNever(kind);
+                        return ScriptElementKind.unknown;
+                    }
+                }
             default:
                 return ScriptElementKind.unknown;
         }

tests/cases/fourslash/navigationItemsSpecialPropertyAssignment.ts

@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts"/>
+
+// @allowJs: true
+// @Filename: /a.js
+////exports.{| "name": "x", "kind": "const" |}x = 0;
+////exports.{| "name": "y", "kind": "function" |}y = function() {};
+////function Cls() {
+////    this.{| "name": "prop", "kind": "property" |}prop = 0;
+////}
+////Cls.{| "name": "staticMethod", "kind": "method" |}staticMethod = function() {};
+////Cls.{| "name": "staticProperty", "kind": "property" |}staticProperty = 0;
+////Cls.prototype.{| "name": "instance", "kind": "method" |}instance = function() {};
+
+for (const marker of test.markers()) {
+    verify.navigationItemsListContains(
+        marker.data.name,
+        marker.data.kind,
+        marker.data.name,
+        "exact");
+}