jupyter - treat slide separation marker correctly

news/changelog-1.5.md

@@ -60,6 +60,7 @@ All changes included in 1.5:
 - When searching for kernelspecs that match `python`, prefer one one that matches an active Python venv.
 - ([#8454](https://github.com/quarto-dev/quarto-cli/issues/8454)): Allow Jupyter engine to handle markdown files with mixed-case extensions.
 - ([#8919](https://github.com/quarto-dev/quarto-cli/issues/8919)): Ensure enough backticks in `quarto convert` from `.ipynb` to `.qmd` files.
+- ([#8998](https://github.com/quarto-dev/quarto-cli/issues/8998)): Interpret slide separation markers `---` correctly when creating the `.ipynb` intermediate notebook from a `.qmd` file.
 
 ## Website Listings
 

src/core/jupyter/jupyter.ts

@@ -427,9 +427,15 @@ export async function quartoMdToJupyter(
     inCodeCell = false,
     inCode = false,
     backtickCount = 0;
-  for (const line of lines(inputContent)) {
+  let currentLine = 0;
+  const contentLines = lines(inputContent);
+  for (currentLine = 0; currentLine < contentLines.length; ++currentLine) {
+    const line = contentLines[currentLine];
     // yaml front matter
-    if (yamlRegEx.test(line) && !inCodeCell && !inCode) {
+    if (
+      yamlRegEx.test(line) && !inCodeCell && !inCode &&
+      contentLines[currentLine + 1]?.trim() !== "" // https://github.com/quarto-dev/quarto-cli/issues/8998
+    ) {
       if (inYaml) {
         lineBuffer.push(line);
         flushLineBuffer("raw", !parsedFrontMatter);

tests/docs/smoke-all/2024/03/22/8998.qmd

@@ -0,0 +1,25 @@
+---
+title: "Habits"
+author: "John Doe"
+format: revealjs
+engine: jupyter
+_quarto:
+  tests:
+    revealjs:
+      - []
+      - ["python"]
+---
+
+- Turn off alarm
+- Get out of bed
+- `{python} 1` 
+
+---
+
+- Get in bed
+- Count sheep
+- `{python} 2`
+
+---
+
+Last slide to recreate the issue