Jupyter - trim whitespace and newlines from captions

news/changelog-1.5.md

@@ -103,6 +103,7 @@ All changes included in 1.5:
 - ([#9422](https://github.com/quarto-dev/quarto-cli/issues/9422)): Improve the stream merging algorithm in output cells to avoid merging outputs that should not be merged.
 - ([#9536](https://github.com/quarto-dev/quarto-cli/issues/9536)): Provide traceback when available in Jupyter error outputs.
 - ([#9470](https://github.com/quarto-dev/quarto-cli/issues/9470)): Fix images rendered by the Jupyter engine to be displayed with the same dimensions as those in notebooks.
+- ([#5413](https://github.com/quarto-dev/quarto-cli/issues/5413)): Fix issue with Jupyter engine cells and images with captions containing newlines.
 
 ## Website Listings
 

src/core/jupyter/jupyter.ts

@@ -1326,7 +1326,12 @@ async function mdFromCodeCell(
   }
 
   // resolve caption (main vs. sub)
-  const { cellCaption, outputCaptions } = resolveCaptions(cell);
+  let { cellCaption, outputCaptions } = resolveCaptions(cell);
+
+  // https://github.com/quarto-dev/quarto-cli/issues/5413
+  outputCaptions = outputCaptions.map((caption) =>
+    caption.trim().replaceAll("\n", " ")
+  );
 
   // cell_type classes
   divMd.push(`.cell `);

tests/docs/smoke-all/2024/06/12/5413.qmd

@@ -0,0 +1,21 @@
+---
+title: issue-5413
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        - ["figcaption.quarto-float-fig"]
+        - []
+---
+
+```{python}
+#| label: fig-1
+#| fig-cap: |
+#|   This is a caption for my figure.
+#|   It is long, so I put it onto two lines
+import numpy as np
+import matplotlib.pyplot as plt
+plt.plot(np.arange(10))
+```
+
+See @fig-1.