Handle TypeScript 4.5 new file extensions .mts and .cts (#11721)

* Handle .mts and .cts

* Update integration tests

* Add changelog

changelog_unreleased/typescript/11721.md

@@ -0,0 +1,7 @@
+#### Support TypeScript 4.5 (#11721 by @sosukesuzuki)
+
+Support new TypeScript 4.5 features.
+
+##### Handle `.mts` and `.cts`
+
+Handle new file extensions `.mts` and `.cts`.

src/language-js/index.js

@@ -67,11 +67,15 @@ const languages = [
     codemirrorMimeType: "text/jsx",
     color: undefined,
   })),
-  createLanguage(require("linguist-languages/data/TypeScript.json"), () => ({
-    since: "1.4.0",
-    parsers: ["typescript", "babel-ts"],
-    vscodeLanguageIds: ["typescript"],
-  })),
+  createLanguage(
+    require("linguist-languages/data/TypeScript.json"),
+    (data) => ({
+      since: "1.4.0",
+      parsers: ["typescript", "babel-ts"],
+      vscodeLanguageIds: ["typescript"],
+      extensions: [...data.extensions, ".mts", ".cts"],
+    })
+  ),
   createLanguage(require("linguist-languages/data/TSX.json"), () => ({
     since: "1.4.0",
     parsers: ["typescript", "babel-ts"],

tests/integration/__tests__/__snapshots__/support-info.js.snap

@@ -394,7 +394,7 @@ exports[`CLI --support-info (stdout) 1`] = `
       \\"codemirrorMimeType\\": \\"application/typescript\\",
       \\"codemirrorMode\\": \\"javascript\\",
       \\"color\\": \\"#2b7489\\",
-      \\"extensions\\": [\\".ts\\"],
+      \\"extensions\\": [\\".ts\\", \\".mts\\", \\".cts\\"],
       \\"interpreters\\": [\\"deno\\", \\"ts-node\\"],
       \\"linguistLanguageId\\": 378,
       \\"name\\": \\"TypeScript\\",