fix(38785): include in NavigationBar child items from default exported functions (microsoft#38915)

Author: a-tarasyuk

src/services/navigationBar.ts

@@ -310,9 +310,11 @@ namespace ts.NavigationBar {
 
             case SyntaxKind.ExportAssignment: {
                 const expression = (<ExportAssignment>node).expression;
-                if (isObjectLiteralExpression(expression)) {
+                const child = isObjectLiteralExpression(expression) ? expression :
+                    isArrowFunction(expression) || isFunctionExpression(expression) ? expression.body : undefined;
+                if (child) {
                     startNode(node);
-                    addChildrenRecursively(expression);
+                    addChildrenRecursively(child);
                     endNode();
                 }
                 else {

tests/cases/fourslash/navigationItemsExportDefaultExpression.ts

@@ -1,8 +1,24 @@
 /// <reference path="fourslash.ts"/>
 
-//// const abc = 12;
 //// export default function () {}
+//// export default function () {
+////     return class Foo {
+////     }
+//// }
+////
 //// export default () => ""
+//// export default () => {
+////     return class Foo {
+////     }
+//// }
+////
+//// export default function f1() {}
+//// export default function f2() {
+////     return class Foo {
+////     }
+//// }
+////
+//// const abc = 12;
 //// export default abc;
 //// export default class AB {}
 //// export default {
@@ -22,11 +38,33 @@ verify.navigationTree({
       "kind": "function",
       "kindModifiers": "export"
     },
+    {
+      "text": "default",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
+    },
     {
       "text": "default",
       "kind": "function",
       "kindModifiers": "export"
     },
+    {
+      "text": "default",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
+    },
     {
       "text": "default",
       "kind": "const",
@@ -65,6 +103,22 @@ verify.navigationTree({
       "text": "default",
       "kind": "const",
       "kindModifiers": "export"
+    },
+    {
+      "text": "f1",
+      "kind": "function",
+      "kindModifiers": "export"
+    },
+    {
+      "text": "f2",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
     }
   ]
 });

tests/cases/fourslash/navigationItemsExportEqualsExpression.ts

@@ -1,10 +1,26 @@
 // 35477
 /// <reference path="fourslash.ts"/>
 
-//// const abc = 12;
-//// export = abc;
 //// export = function () {}
+//// export = function () {
+////     return class Foo {
+////     }
+//// }
+////
 //// export = () => ""
+//// export = () => {
+////     return class Foo {
+////     }
+//// }
+////
+//// export = function f1() {}
+//// export = function f2() {
+////     return class Foo {
+////     }
+//// }
+////
+//// const abc = 12;
+//// export = abc;
 //// export = class AB {}
 //// export = {
 ////     a: 1,
@@ -23,11 +39,49 @@ verify.navigationTree({
       "kind": "function",
       "kindModifiers": "export"
     },
+    {
+      "text": "export=",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
+    },
+    {
+      "text": "export=",
+      "kind": "function",
+      "kindModifiers": "export"
+    },
+    {
+      "text": "export=",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
+    },
     {
       "text": "export=",
       "kind": "function",
       "kindModifiers": "export"
     },
+    {
+      "text": "export=",
+      "kind": "function",
+      "kindModifiers": "export",
+      "childItems": [
+        {
+          "text": "Foo",
+          "kind": "class"
+        }
+      ]
+    },
     {
       "text": "export=",
       "kind": "class",