Add test: quarto inspect standalone file should omit project in RStudio

Also adds _setIsRStudioForTest() override to platform.ts to avoid
Deno.env.set() race conditions in parallel tests (#14218, PR #12621).

Author: cderv

src/core/platform.ts

@@ -14,7 +14,15 @@ export function isWSL() {
   return !!Deno.env.get("WSL_DISTRO_NAME");
 }
 
+// Test override for isRStudio — avoids Deno.env.set() race conditions
+// in parallel tests. See quarto-dev/quarto-cli#14218 and PR #12621.
+let _isRStudioOverride: boolean | undefined;
+export function _setIsRStudioForTest(value: boolean | undefined) {
+  _isRStudioOverride = value;
+}
+
 export function isRStudio() {
+  if (_isRStudioOverride !== undefined) return _isRStudioOverride;
   return !!Deno.env.get("RSTUDIO");
 }
 

tests/docs/inspect/standalone-hello.qmd

@@ -0,0 +1,6 @@
+---
+title: Hello
+format: html
+---
+
+Hello world.

tests/smoke/inspect/inspect-standalone-rstudio.test.ts

@@ -0,0 +1,78 @@
+/*
+* inspect-standalone-rstudio.test.ts
+*
+* Copyright (C) 2020-2026 Posit Software, PBC
+*
+*/
+
+import { existsSync } from "../../../src/deno_ral/fs.ts";
+import { _setIsRStudioForTest } from "../../../src/core/platform.ts";
+import {
+  ExecuteOutput,
+  testQuartoCmd,
+} from "../../test.ts";
+import { assert, assertEquals } from "testing/asserts";
+
+// Test: standalone file inspect with RStudio override should NOT emit project.
+// Uses _setIsRStudioForTest to avoid Deno.env.set() race conditions in
+// parallel tests (see #14218, PR #12621).
+(() => {
+  const input = "docs/inspect/standalone-hello.qmd";
+  const output = "docs/inspect/standalone-hello.json";
+  testQuartoCmd(
+    "inspect",
+    [input, output],
+    [
+      {
+        name: "inspect-standalone-no-project-in-rstudio",
+        verify: async (_outputs: ExecuteOutput[]) => {
+          assert(existsSync(output));
+          const json = JSON.parse(Deno.readTextFileSync(output));
+          assertEquals(json.project, undefined,
+            "Standalone file inspect should not emit 'project' when in RStudio");
+        }
+      }
+    ],
+    {
+      setup: async () => {
+        _setIsRStudioForTest(true);
+      },
+      teardown: async () => {
+        _setIsRStudioForTest(undefined);
+        if (existsSync(output)) {
+          Deno.removeSync(output);
+        }
+      }
+    },
+  );
+})();
+
+// Test: standalone file inspect WITHOUT RStudio should still emit project
+(() => {
+  const input = "docs/inspect/standalone-hello.qmd";
+  const output = "docs/inspect/standalone-hello-nors.json";
+  testQuartoCmd(
+    "inspect",
+    [input, output],
+    [
+      {
+        name: "inspect-standalone-has-project-outside-rstudio",
+        verify: async (_outputs: ExecuteOutput[]) => {
+          assert(existsSync(output));
+          const json = JSON.parse(Deno.readTextFileSync(output));
+          assert(json.project !== undefined,
+            "Standalone file inspect should emit 'project' when not in RStudio");
+          assert(json.project.dir !== undefined,
+            "project.dir should be set");
+        }
+      }
+    ],
+    {
+      teardown: async () => {
+        if (existsSync(output)) {
+          Deno.removeSync(output);
+        }
+      }
+    },
+  );
+})();