convert - handle cells with both YAML and implicit titles

news/changelog-1.7.md

@@ -57,6 +57,7 @@ All changes included in 1.7:
 
 - ([#12042](https://github.com/quarto-dev/quarto-cli/issues/12042)): Preserve Markdown content that follows YAML metadata in a `raw` .ipynb cell.
 - ([#12318](https://github.com/quarto-dev/quarto-cli/issues/12318)): Ensure enough line breaks between cells that might be trimmed.
+- ([#12440](https://github.com/quarto-dev/quarto-cli/issues/12440)): Support conversion of cells with both YAML and implicit titles.
 
 ### `quarto inspect`
 

src/core/jupyter/jupyter-fixups.ts

@@ -12,7 +12,7 @@ import { Metadata } from "../../config/types.ts";
 import { lines } from "../lib/text.ts";
 import { markdownWithExtractedHeading } from "../pandoc/pandoc-partition.ts";
 import { partitionYamlFrontMatter, readYamlFromMarkdown } from "../yaml.ts";
-import { JupyterNotebook, JupyterOutput } from "./types.ts";
+import { JupyterCell, JupyterNotebook, JupyterOutput } from "./types.ts";
 import {
   jupyterCellSrcAsLines,
   jupyterCellSrcAsStr,
@@ -149,6 +149,34 @@ export function fixupFrontMatter(nb: JupyterNotebook): JupyterNotebook {
     return lns.map((line) => line.endsWith("\n") ? line : `${line}\n`);
   };
 
+  // https://github.com/quarto-dev/quarto-cli/issues/12440
+  // first, we need to find cells that have front matter _and_ markdown content,
+  // and split them into two cells.
+  const newCells: JupyterCell[] = [];
+  nb.cells.forEach((cell) => {
+    if (cell.cell_type === "raw" || cell.cell_type === "markdown") {
+      const partitioned = partitionYamlFrontMatter(jupyterCellSrcAsStr(cell)) ||
+        undefined;
+      if (partitioned?.yaml.trim()) {
+        newCells.push({
+          cell_type: "raw",
+          source: nbLines(partitioned.yaml.split("\n")),
+          metadata: {},
+        });
+      }
+      if (partitioned?.markdown.trim()) {
+        newCells.push({
+          cell_type: "markdown",
+          source: nbLines(partitioned.markdown.split("\n")),
+          metadata: {},
+        });
+      }
+    } else {
+      newCells.push(cell);
+    }
+  });
+  nb.cells = newCells;
+
   // look for the first raw block that has a yaml object
   let partitioned: { yaml: string; markdown: string } | undefined;
   const frontMatterCellIndex = nb.cells.findIndex((cell) => {

src/core/pandoc/pandoc-partition.ts

@@ -84,7 +84,7 @@ export function markdownWithExtractedHeading(markdown: string) {
         const parsedHeading = parsePandocTitle(line);
         headingText = parsedHeading.heading;
         headingAttr = parsedHeading.attr;
-        contentBeforeHeading = mdLines.length !== 0;
+        contentBeforeHeading = (mdLines.join("").trim()).length !== 0;
       } else if (line.match(/^=+\s*$/) || line.match(/^-+\s*$/)) {
         const prevLine = mdLines[mdLines.length - 1];
         if (prevLine) {

tests/docs/convert/issue-12440.qmd

@@ -0,0 +1,18 @@
+---
+format: typst
+---
+
+# This is what happens when I don't set the title.
+
+## This is a level 2 heading
+
+This is some paragraph text.
+
+```{python}
+# This is an executable Python code block.
+print("This is the output of an executable Python code block.")
+```
+
+## This is another level 2 heading
+
+This is some more paragraph text.

tests/smoke/convert/convert-issue-12042.test.ts

@@ -1,5 +1,5 @@
 /*
-* convert-backticks.test.ts
+* convert-issue-12042.test.ts
 *
 * Copyright (C) 2020-2024 Posit Software, PBC
 *
@@ -12,7 +12,6 @@ import {
 import { assert } from "testing/asserts";
 
 (() => {
-  const input = "docs/convert/backticks.ipynb";
   testQuartoCmd(
     "convert",
     ["docs/convert/issue-12042.ipynb"],

tests/smoke/convert/convert-issue-12440.test.ts

@@ -0,0 +1,41 @@
+/*
+* docs/convert/issue-12440.test.ts
+*
+* Copyright (C) 2025 Posit Software, PBC
+*
+*/
+import { existsSync } from "../../../src/deno_ral/fs.ts";
+import { quarto } from "../../../src/quarto.ts";
+import {
+  ExecuteOutput,
+  testQuartoCmd,
+  removeFilesTeardown,
+} from "../../test.ts";
+import { assert } from "testing/asserts";
+
+(() => {
+  const input = "docs/convert/issue-12440.qmd";
+  testQuartoCmd(
+    "convert",
+    ["docs/convert/issue-12440.qmd"],
+    [
+      {
+        name: "convert-mixed-yaml-markdown-cell",
+        verify: async (outputs: ExecuteOutput[]) => {
+          await quarto([
+            "convert",
+            "docs/convert/issue-12440.ipynb",
+            "--output",
+            "docs/convert/issue-12440-out.qmd",
+          ]);
+          const txt = Deno.readTextFileSync("docs/convert/issue-12440-out.qmd");
+          assert(txt.includes("title: This is what happens when I don't set the title"), "Markdown text not found in output");
+        }
+      }
+    ],
+    removeFilesTeardown([
+      "docs/convert/issue-12440-out.qmd",
+      "docs/convert/issue-12440.ipynb"
+    ]),
+  );
+})();

tests/test.ts

@@ -336,3 +336,13 @@ function readExecuteOutput(log: string) {
     return JSON.parse(line) as ExecuteOutput;
   });
 }
+
+export const removeFilesTeardown = (fileList: string[]) => {
+  return {
+    teardown: async () => {
+      for (const file of fileList) {
+        safeRemoveSync(file);
+      }
+    }
+  };
+}