fix(node): regression where ts files were sometimes resolved instead of js (#26971)

ext/node/polyfills/01_require.js

@@ -1060,22 +1060,39 @@ Module.prototype._compile = function (content, filename, format) {
   return result;
 };
 
-Module._extensions[".js"] =
+Module._extensions[".js"] = function (module, filename) {
-  Module._extensions[".ts"] =
+  // We don't define everything on Module.extensions in
-  Module._extensions[".jsx"] =
+  // order to prevent probing for these files
-  Module._extensions[".tsx"] =
+  if (
-    function (module, filename) {
+    StringPrototypeEndsWith(filename, ".js") ||
+    StringPrototypeEndsWith(filename, ".ts") ||
+    StringPrototypeEndsWith(filename, ".jsx") ||
+    StringPrototypeEndsWith(filename, ".tsx")
+  ) {
+    return loadMaybeCjs(module, filename);
+  } else if (StringPrototypeEndsWith(filename, ".mts")) {
+    return loadESMFromCJS(module, filename);
+  } else if (StringPrototypeEndsWith(filename, ".cts")) {
+    return loadCjs(module, filename);
+  } else {
+    return loadMaybeCjs(module, filename);
+  }
+};
+
+Module._extensions[".cjs"] = loadCjs;
+Module._extensions[".mjs"] = loadESMFromCJS;
+Module._extensions[".wasm"] = loadESMFromCJS;
+
+function loadMaybeCjs(module, filename) {
   const content = op_require_read_file(filename);
   const format = op_require_is_maybe_cjs(filename) ? undefined : "module";
   module._compile(content, filename, format);
-    };
+}
 
-Module._extensions[".cjs"] =
+function loadCjs(module, filename) {
-  Module._extensions[".cts"] =
-    function (module, filename) {
   const content = op_require_read_file(filename);
   module._compile(content, filename, "commonjs");
-    };
+}
 
 function loadESMFromCJS(module, filename, code) {
   const namespace = op_import_sync(
@@ -1086,11 +1103,6 @@ function loadESMFromCJS(module, filename, code) {
   module.exports = namespace;
 }
 
-Module._extensions[".mjs"] =
-  Module._extensions[".mts"] =
-  Module._extensions[".wasm"] =
-    loadESMFromCJS;
-
 function stripBOM(content) {
   if (StringPrototypeCharCodeAt(content, 0) === 0xfeff) {
     content = StringPrototypeSlice(content, 1);

tests/specs/npm/pkg_index_ts_and_js/__test__.jsonc

@@ -0,0 +1,4 @@
+{
+  "args": "run index.js",
+  "output": "Hi\nWasm\nJSON\n"
+}

tests/specs/npm/pkg_index_ts_and_js/index.js

@@ -0,0 +1 @@
+import "package";

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/index.js

@@ -0,0 +1,3 @@
+require("./subdir");
+require("./wasm");
+require("./json");

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/json/index.js

@@ -0,0 +1 @@
+console.log("JSON");

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/json/index.json

@@ -0,0 +1 @@
+{}

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "package"
+}

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/subdir/index.js

@@ -0,0 +1 @@
+console.log("Hi")

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/subdir/index.ts

@@ -0,0 +1 @@
+console.log("No");

tests/specs/npm/pkg_index_ts_and_js/node_modules/package/wasm/index.js

@@ -0,0 +1 @@
+console.log("Wasm");

tests/specs/npm/pkg_index_ts_and_js/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "package": "*"
+  }
+}