Allow valid contextual keyword completions even when an auto-import by the same name exists (microsoft#56001)

Author: andrewbranch

src/services/completions.ts

@@ -1329,7 +1329,11 @@ function completionInfoFromData(
 
  if (keywordFilters !== KeywordCompletionFilters.None) {
  for (const keywordEntry of getKeywordCompletions(keywordFilters, !insideJsDocTagTypeExpression && isSourceFileJS(sourceFile))) {
- if (isTypeOnlyLocation && isTypeKeyword(stringToToken(keywordEntry.name)!) || !uniqueNames.has(keywordEntry.name)) {
+ if (
+ isTypeOnlyLocation && isTypeKeyword(stringToToken(keywordEntry.name)!) ||
+ !isTypeOnlyLocation && isContextualKeywordInAutoImportableExpressionSpace(keywordEntry.name) ||
+ !uniqueNames.has(keywordEntry.name)
+ ) {
  uniqueNames.add(keywordEntry.name);
  insertSorted(entries, keywordEntry, compareCompletionEntries, /*allowDuplicates*/ true);
  }
@@ -5829,3 +5833,31 @@ function toUpperCharCode(charCode: number) {
  }
  return charCode;
 }
+
+/**
+ * These are all the contextual keywords that would be valid to auto-import
+ * in expression space and also a valid keyword in the same location, depending
+ * on what gets typed afterwards. In these cases, we want to offer both the
+ * auto-import and the keyword completion. For example,
+ *
+ * ```ts
+ * type
+ * ```
+ *
+ * may be the beginning of a type alias declaration (keyword completion), or
+ * it may be the beginning of
+ *
+ * ```ts
+ * import { type } from "os";
+ * type() === "Darwin" ? doSomething() : doSomethingElse();
+ * ```
+ */
+function isContextualKeywordInAutoImportableExpressionSpace(keyword: string) {
+ return keyword === "abstract" ||
+ keyword === "async" ||
+ keyword === "await" ||
+ keyword === "declare" ||
+ keyword === "module" ||
+ keyword === "namespace" ||
+ keyword === "type";
+}

tests/cases/fourslash/completionsImportTypeKeyword.ts

@@ -0,0 +1,32 @@
+/// <reference path="fourslash.ts" />
+
+// @module: nodenext
+
+// @Filename: /os.d.ts
+//// declare module "os" {
+//// export function type(): string;
+//// }
+
+// @Filename: /index.ts
+//// type/**/
+
+verify.completions({
+ marker: "",
+ includes: [
+ {
+ name: "type",
+ sortText: completion.SortText.GlobalsOrKeywords,
+ },
+ {
+ name: "type",
+ source: "os",
+ sourceDisplay: "os",
+ hasAction: true,
+ sortText: completion.SortText.AutoImportSuggestions
+ }
+ ],
+ preferences: {
+ includeCompletionsForModuleExports: true,
+ allowIncompleteCompletions: true,
+ },
+});