Support completions inside JSDoc before EndOfFileToken (#25568)

Author: Andy

src/services/utilities.ts

@@ -755,7 +755,7 @@ namespace ts {
         return result;
 
         function find(n: Node): Node | undefined {
-            if (isNonWhitespaceToken(n)) {
+            if (isNonWhitespaceToken(n) && n.kind !== SyntaxKind.EndOfFileToken) {
                 return n;
             }
 
@@ -786,16 +786,14 @@ namespace ts {
                 }
             }
 
-            Debug.assert(startNode !== undefined || n.kind === SyntaxKind.SourceFile || isJSDocCommentContainingNode(n));
+            Debug.assert(startNode !== undefined || n.kind === SyntaxKind.SourceFile || n.kind === SyntaxKind.EndOfFileToken || isJSDocCommentContainingNode(n));
 
             // Here we know that none of child token nodes embrace the position,
             // the only known case is when position is at the end of the file.
             // Try to find the rightmost token in the file without filtering.
             // Namely we are skipping the check: 'position < node.end'
-            if (children.length) {
-                const candidate = findRightmostChildNodeWithTokens(children, /*exclusiveStartPosition*/ children.length, sourceFile);
-                return candidate && findRightmostToken(candidate, sourceFile);
-            }
+            const candidate = findRightmostChildNodeWithTokens(children, /*exclusiveStartPosition*/ children.length, sourceFile);
+            return candidate && findRightmostToken(candidate, sourceFile);
         }
     }
 
@@ -1048,7 +1046,7 @@ namespace ts {
     function nodeHasTokens(n: Node, sourceFile: SourceFileLike): boolean {
         // If we have a token or node that has a non-zero width, it must have tokens.
         // Note: getWidth() does not take trivia into account.
-        return n.getWidth(sourceFile) !== 0;
+        return n.kind === SyntaxKind.EndOfFileToken ? !!(n as EndOfFileToken).jsDoc : n.getWidth(sourceFile) !== 0;
     }
 
     export function getNodeModifiers(node: Node): string {

tests/cases/fourslash/completionsPaths.ts

@@ -23,5 +23,7 @@
 // @Filename: /src/folder/4.ts
 ////const foo = require(`x//*4*/`);
 
-verify.completionsAt("1", ["y", "x"], { isNewIdentifierLocation: true });
-verify.completionsAt(["2", "3", "4"], ["bar", "foo"], { isNewIdentifierLocation: true });
+verify.completions(
+    { marker: "1", exact: ["y", "x"], isNewIdentifierLocation: true },
+    { marker: ["2", "3", "4"], exact: ["bar", "foo"], isNewIdentifierLocation: true },
+);

tests/cases/fourslash/completionsPaths_importType.ts

@@ -0,0 +1,23 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+// @moduleResolution: node
+
+// @Filename: /ns.ts
+////file content not read
+
+// @Filename: /node_modules/package/index.ts
+////file content not read
+
+// @Filename: /usage.ts
+////type A = typeof import("p/*1*/");
+////type B = import(".//*2*/");
+
+// @Filename: /user.js
+/////** @type {import("/*3*/")} */
+
+verify.completions(
+    { marker: "1", exact: "package", isNewIdentifierLocation: true },
+    { marker: "2", exact: ["lib", "ns", "user", "node_modules"], isNewIdentifierLocation: true },
+    { marker: "3", exact: ["package"], isNewIdentifierLocation: true },
+);