feat(node): stabilize detecting if CJS via `"type": "commonjs"` in a package.json (#26439)

This will respect `"type": "commonjs"` in a package.json to determine if
`.js`/`.jsx`/`.ts`/.tsx` files are CJS or ESM. If the file is found to
be ESM it will be loaded as ESM though.

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/integration/lsp_tests.rs b/tests/integration/lsp_tests.rs
index af5f9de23..dcef69608 100644
--- a/tests/integration/lsp_tests.rs
+++ b/tests/integration/lsp_tests.rs
@@ -16140,6 +16140,55 @@ fn lsp_cjs_import_dual() {
 }
 
 #[test]
+fn lsp_type_commonjs() {
+  let context = TestContextBuilder::new()
+    .use_http_server()
+    .use_temp_cwd()
+    .add_npm_env_vars()
+    .build();
+  let temp_dir = context.temp_dir();
+  temp_dir.write("deno.json", r#"{}"#);
+  temp_dir.write(
+    "package.json",
+    r#"{
+  "type": "commonjs",
+  "dependencies": {
+    "@denotest/dual-cjs-esm": "1"
+  }
+}"#,
+  );
+  context.run_npm("install");
+
+  let mut client = context.new_lsp_command().build();
+  client.initialize_default();
+  let main_url = temp_dir.path().join("main.ts").url_file();
+  let diagnostics = client.did_open(
+    json!({
+      "textDocument": {
+        "uri": main_url,
+        "languageId": "typescript",
+        "version": 1,
+        // getKind() should resolve as "cjs" and cause a type checker error
+        "text": "import mod = require('@denotest/dual-cjs-esm');\nconst kind: 'other' = mod.getKind(); console.log(kind);",
+      }
+    }),
+  );
+  assert_eq!(
+    json!(diagnostics.all()),
+    json!([{
+      "range": {
+          "start": { "line": 1, "character": 6, },
+          "end": { "line": 1, "character": 10, },
+      },
+      "severity": 1,
+      "code": 2322,
+      "source": "deno-ts",
+      "message": "Type '\"cjs\"' is not assignable to type '\"other\"'.",
+    }])
+  );
+}
+
+#[test]
 fn lsp_ts_code_fix_any_param() {
   let context = TestContextBuilder::new().use_temp_cwd().build();
   let temp_dir = context.temp_dir();