Fix embed notebook preview missing from _site on re-render

.claude/rules/testing/unit-test-with-r.md

@@ -1,15 +1,18 @@
 ---
 paths:
   - "tests/unit/preview-subdir-knitr-cwd.test.ts"
+  - "tests/smoke/embed/render-embed-website-rerender.test.ts"
 ---
 
-# R unit test that changes working directory
+# R tests that change working directory
 
-This test runs a knitr subprocess with cwd set to a scratch directory
-(required to reproduce the bug). R's `.Rprofile` lookup is cwd-exact, so it
-won't pick up `tests/renv` activation there — on CI the R subprocess fails
-with `there is no package called 'rmarkdown'`. `setup()` writes a
+These tests run a knitr subprocess with cwd set to a scratch or fixture
+directory (required to reproduce the bug). R's `.Rprofile` lookup is
+cwd-exact, so it won't pick up `tests/renv` activation there — on CI the R
+subprocess fails with `there is no package called 'rmarkdown'`. `setup()`
+calls `writeTestsRenvProfile(dir)` (`tests/utils.ts`), which writes a
 `.Rprofile` into the fixture dir to re-activate renv against the real
-`tests/` project.
+`tests/` project. Any new test whose knitr cwd is outside `tests/` needs the
+same call.
 
 **Details:** `llm-docs/testing-patterns.md` → "R Tests That Change Working Directory"

llm-docs/testing-patterns.md

@@ -218,6 +218,7 @@ unitTest("runs from workingDir", async () => {
 
 **Key points:**
 
+- A test that runs R/knitr from the new cwd also needs the renv activation described in "R Tests That Change Working Directory" below.
 - The harness calls `cwd()` **before** `setup()`, so the directory must already exist when `cwd()` runs — create it at module scope, not in `setup`.
 - `teardown` runs **before** the harness restores the cwd, so on Windows the temp dir may still be the cwd and resist removal.
   Wrap the removal in try/catch (best-effort) — see `tests/smoke/use/template.test.ts` and `tests/unit/dotenv-config.test.ts`.
@@ -429,7 +430,7 @@ Most knitr tests never leave `tests/` — they pass paths relative to the curren
 A test that changes cwd through `TestContext.cwd()` loses that activation. The R subprocess starts outside `tests/`, and package loads may fail with `there is no package called 'rmarkdown'`.
 A developer machine with rmarkdown on the default `.libPaths()` may mask this CI failure.
 
-**Fix:** write a `.Rprofile` in the fixture cwd that points renv to the test project:
+**Fix:** call `writeTestsRenvProfile(dir)` (`tests/utils.ts`) in `setup()` to write a `.Rprofile` in the fixture cwd that points renv to the test project. It writes:
 
 ```r
 Sys.setenv(RENV_PROJECT = "<absolute path to tests/>")

news/changelog-1.11.md

@@ -65,6 +65,7 @@ All changes included in 1.11:
 
 ### Websites
 
+- ([#10756](https://github.com/quarto-dev/quarto-cli/issues/10756)): Fix the notebook preview of an embedded `.qmd` file going missing from the output directory when a project is rendered again, which broke its source notebook link.
 - ([#14974](https://github.com/quarto-dev/quarto-cli/issues/14974)): Fix math in `.llms.md` files from `llms-txt` coming out garbled with the default `mathjax` method, and with `katex` and `webtex`. Math is now written as `$...$` and `$$...$$` with the `mathjax`, `katex`, `webtex` and `mathml` methods.
 
 ## Lua API

src/render/notebook/notebook-context.ts

@@ -77,7 +77,7 @@ export function notebookContext(): NotebookContext {
     notebooks[nbAbsPath] = nb;
     needRewrite = true;
 
-    if (context) {
+    if (context && !cached) {
       const contrib = contributor(renderType);
       if (contrib.cache) {
         contrib.cache(output, context);
@@ -289,19 +289,32 @@ export function notebookContext(): NotebookContext {
       // If there is a source representation of the qmd file
       // we should use that, which will prevent rexecution of the
       // QMD
-      const notebook = notebooks[nbAbsPath];
-      const toRenderPath = notebook
-        ? notebook[kQmdIPynb] ? notebook[kQmdIPynb].path : nbAbsPath
+      const qmdIpynb = notebooks[nbAbsPath]?.[kQmdIPynb];
+      // A notebook revived from the scratch cache is rendered from beside the
+      // source, so the preview and its files land where a fresh render puts them
+      const staged = qmdIpynb?.cached === true;
+      const toRenderPath = qmdIpynb
+        ? staged ? qmdIpynb.hrefPath : qmdIpynb.path
         : nbAbsPath;
+      if (staged) {
+        Deno.copyFileSync(qmdIpynb.path, qmdIpynb.hrefPath);
+      }
 
-      const renderedFile = await contributor(renderType).render(
-        toRenderPath,
-        format,
-        token(),
-        services,
-        notebookMetadata,
-        project,
-      );
+      let renderedFile: NotebookRenderResult;
+      try {
+        renderedFile = await contributor(renderType).render(
+          toRenderPath,
+          format,
+          token(),
+          services,
+          notebookMetadata,
+          project,
+        );
+      } finally {
+        if (staged) {
+          safeRemoveIfExists(toRenderPath);
+        }
+      }
 
       addRendering(nbAbsPath, renderType, renderedFile, project);
       if (!notebooks[nbAbsPath][renderType]) {

tests/docs/embed/website-rerender/.gitignore

@@ -0,0 +1,5 @@
+/.quarto/
+/_site/
+
+**/*.quarto_ipynb
+/.Rprofile

tests/docs/embed/website-rerender/_quarto.yml

@@ -0,0 +1,4 @@
+project:
+  type: website
+
+format: html

tests/docs/embed/website-rerender/index.qmd

@@ -0,0 +1,5 @@
+---
+title: "Home"
+---
+
+{{< embed source.qmd#fig-cars >}}

tests/docs/embed/website-rerender/source.qmd

@@ -0,0 +1,9 @@
+---
+title: "Source"
+---
+
+```{r}
+#| label: fig-cars
+#| fig-cap: "Cars"
+plot(cars)
+```

tests/docs/site/.gitignore

@@ -1 +1,3 @@
 /.quarto/
+
+**/*.quarto_ipynb

tests/smoke/embed/render-embed-website-rerender.test.ts

@@ -0,0 +1,91 @@
+/*
+ * render-embed-website-rerender.test.ts
+ *
+ * Copyright (C) 2026 Posit Software, PBC
+ */
+
+import { join, resolve } from "../../../src/deno_ral/path.ts";
+import { existsSync, safeRemoveSync } from "../../../src/deno_ral/fs.ts";
+import { Element } from "../../../src/core/deno-dom.ts";
+import { docs, writeTestsRenvProfile } from "../../utils.ts";
+import {
+  ensureHtmlSelectorSatisfies,
+  fileExists,
+  noErrors,
+  pathDoNotExists,
+} from "../../verify.ts";
+import { test } from "../../test.ts";
+import { runQuarto } from "../../quarto-cmd.ts";
+
+// A re-render of a website must keep the notebook preview of an embedded
+// qmd, even though the embed notebook is now served from the project
+// scratch cache (#10756)
+const projectDir = resolve(docs("embed/website-rerender"));
+const siteDir = join(projectDir, "_site");
+
+const removeGenerated = () => {
+  for (
+    const name of [
+      "_site",
+      ".quarto",
+      "index_files",
+      "source.embed_files",
+      "source_files",
+      "source.embed.ipynb",
+      "source.embed-preview.html",
+      ".Rprofile",
+    ]
+  ) {
+    safeRemoveSync(join(projectDir, name), { recursive: true });
+  }
+};
+
+test({
+  name: "embed qmd preview survives a second website render (#10756)",
+  context: {
+    // Rendering from outside the project loses the preview regardless of
+    // this fix (#15004), so run from the project directory
+    cwd: () => projectDir,
+    setup: () => {
+      removeGenerated();
+      // knitr runs from the project dir, outside tests/
+      writeTestsRenvProfile(projectDir);
+      return Promise.resolve();
+    },
+    teardown: () => {
+      removeGenerated();
+      return Promise.resolve();
+    },
+  },
+  execute: async (logFile?: string) => {
+    await runQuarto(["render", projectDir], { logFile, throwOnFailure: false });
+    await runQuarto(["render", projectDir], { logFile, throwOnFailure: false });
+  },
+  verify: [
+    noErrors,
+    fileExists(join(siteDir, "source.embed-preview.html")),
+    // download target of the "Source" link
+    fileExists(join(siteDir, "source.qmd")),
+    // every figure in the preview resolves to a non-empty file in _site
+    ensureHtmlSelectorSatisfies(
+      join(siteDir, "source.embed-preview.html"),
+      "img.figure-img",
+      (nodeList) => {
+        const srcs = Array.from(nodeList).map((n) =>
+          (n as Element).getAttribute("src")
+        );
+        return srcs.length > 0 && srcs.every((src) =>
+          src !== null && existsSync(join(siteDir, src)) &&
+          Deno.statSync(join(siteDir, src)).size > 0
+        );
+      },
+    ),
+    // figure files were never relocated under the scratch dir
+    pathDoNotExists(join(siteDir, ".quarto")),
+    // revived notebook isn't re-cached into a nested scratch dir
+    pathDoNotExists(join(projectDir, ".quarto", "embed", ".quarto")),
+    // staged notebook is removed after rendering the preview
+    pathDoNotExists(join(projectDir, "source.embed.ipynb")),
+  ],
+  type: "smoke",
+});

tests/unit/preview-subdir-knitr-cwd.test.ts

@@ -29,12 +29,8 @@
 
 import { unitTest } from "../test.ts";
 import { assert } from "testing/asserts";
-import {
-  dirname,
-  fromFileUrl,
-  isAbsolute,
-  join,
-} from "../../src/deno_ral/path.ts";
+import { dirname, isAbsolute, join } from "../../src/deno_ral/path.ts";
+import { writeTestsRenvProfile } from "../utils.ts";
 import { existsSync } from "../../src/deno_ral/fs.ts";
 import { which } from "../../src/core/path.ts";
 import { projectContext } from "../../src/project/project-context.ts";
@@ -160,13 +156,7 @@ unitTest(
       // Re-activate renv against the real tests/ project, regardless of
       // this fixture's cwd — see llm-docs/testing-patterns.md → "R Tests
       // That Change Working Directory" for why this is needed.
-      const testsDir = dirname(dirname(fromFileUrl(import.meta.url)))
-        .replaceAll("\\", "/");
-      Deno.writeTextFileSync(
-        join(e2eProjDir, ".Rprofile"),
-        `Sys.setenv(RENV_PROJECT = "${testsDir}")\n` +
-          `source("${testsDir}/renv/activate.R")\n`,
-      );
+      writeTestsRenvProfile(e2eProjDir);
 
       Deno.writeTextFileSync(
         join(e2eProjDir, "_quarto.yml"),

tests/utils.ts

@@ -5,7 +5,7 @@
 *
 */
 
-import { basename, dirname, extname, join, relative } from "../src/deno_ral/path.ts";
+import { basename, dirname, extname, fromFileUrl, join, relative } from "../src/deno_ral/path.ts";
 import { parseFormatString } from "../src/core/pandoc/pandoc-formats.ts";
 import { kMetadataFormat, kOutputExt, kOutputFile } from "../src/config/constants.ts";
 import { pathWithForwardSlashes, safeExistsSync } from "../src/core/path.ts";
@@ -244,6 +244,19 @@ export function docs(path: string): string {
   return join("docs", path);
 }
 
+// Write a `.Rprofile` into `dir` that activates the tests/ renv project.
+// R reads `.Rprofile` from the exact cwd only, so an R subprocess started
+// outside tests/ (a test using `TestContext.cwd`) would not see the renv
+// library holding knitr/rmarkdown on CI.
+export function writeTestsRenvProfile(dir: string) {
+  const testsDir = pathWithForwardSlashes(dirname(fromFileUrl(import.meta.url)));
+  Deno.writeTextFileSync(
+    join(dir, ".Rprofile"),
+    `Sys.setenv(RENV_PROJECT = "${testsDir}")\n` +
+      `source("${testsDir}/renv/activate.R")\n`,
+  );
+}
+
 export function fileLoader(...path: string[]) {
   return (file: string, to: string) => {
     const input = docs(join(...path, file));