Path completions for import types (#23082)

* Path completions

* Add missing flag to test

* Minify test, fix lint

Author: weswigham

src/services/completions.ts

@@ -380,6 +380,8 @@ namespace ts.Completions {
                         //      }
                         //      let x: Foo["/*completion position*/"]
                         return stringLiteralCompletionsFromProperties(typeChecker.getTypeFromTypeNode((node.parent.parent as IndexedAccessTypeNode).objectType));
+                    case SyntaxKind.ImportTypeNode:
+                        return { kind: StringLiteralCompletionKind.Paths, paths: PathCompletions.getStringLiteralCompletionsFromModuleNames(sourceFile, node, compilerOptions, host, typeChecker) };
                     default:
                         return undefined;
                 }

tests/cases/fourslash/fourslash.ts

@@ -201,14 +201,6 @@ declare namespace FourSlashInterface {
         assertHasRanges(ranges: Range[]): void;
         caretAtMarker(markerName?: string): void;
         completionsAt(markerName: string | ReadonlyArray<string>, completions: ReadonlyArray<string | { name: string, insertText?: string, replacementSpan?: Range }>, options?: CompletionsAtOptions): void;
-        completionsAndDetailsAt(
-            markerName: string,
-            completions: {
-                excludes?: ReadonlyArray<string>,
-                //TODO: better type
-                entries: ReadonlyArray<{ entry: any, details: any }>,
-            },
-        ): void; //TODO: better type
         applyCodeActionFromCompletion(markerName: string, options: {
             name: string,
             source?: string,

tests/cases/fourslash/importTypeModuleCompletions.ts

@@ -0,0 +1,13 @@
+/// <reference path="fourslash.ts" />
+
+// @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 = typeof import(".//*2*/");
+verify.completionsAt("1", ["package"], { isNewIdentifierLocation: true });
+verify.completionsAt("2", ["lib", "ns", "node_modules"], { isNewIdentifierLocation: true });