Fix Google Scholar references missing for a bare YAML bibliography

news/changelog-1.11.md

@@ -65,6 +65,7 @@ All changes included in 1.11:
 - ([#15115](https://github.com/quarto-dev/quarto-cli/pull/15115)): Fix Google Scholar writing two `citation_reference` tags for a reference defined in two bibliography files. The tag now describes the entry Pandoc renders.
 - ([#15118](https://github.com/quarto-dev/quarto-cli/pull/15118)): Fix Google Scholar metadata missing the first and last page of bibliography entries, and giving wrong pages for a citation `page` written with an en-dash or as a page list.
 - ([#15125](https://github.com/quarto-dev/quarto-cli/pull/15125)): Fix Google Scholar metadata failing the render with a CSL JSON (`.json`) bibliography.
+- ([#15128](https://github.com/quarto-dev/quarto-cli/pull/15128)): Fix Google Scholar metadata missing references with a YAML bibliography not wrapped in `---` delimiters.
 
 ### `pdf`
 

src/core/bibliography.ts

@@ -13,9 +13,23 @@ import { Metadata } from "../config/types.ts";
 import { asArray } from "./array.ts";
 import { CSL } from "./csl.ts";
 
+import { FAILSAFE_SCHEMA, loadAll, Type } from "yaml";
+
 import { execProcess } from "./process.ts";
 import { pandocBinaryPath } from "./resources.ts";
 
+// Keeps every scalar as written and, like pandoc, accepts any tag (!!int,
+// !custom, ...) by keeping the untagged value
+const kBibliographyYamlSchema = FAILSAFE_SCHEMA.extend(
+  (["scalar", "sequence", "mapping"] as const).map((kind) =>
+    new Type("", {
+      kind,
+      multi: true,
+      construct: (data: unknown) => data ?? "",
+    })
+  ),
+);
+
 export async function bibliographyCslJson(input: string, metadata: Metadata) {
   const bibliography = metadata[kBibliography] as string | string[];
   if (bibliography) {
@@ -84,15 +98,36 @@ export async function renderToCSLJSON(
     // The bibliopath might end up as an absolute path
     // in which case just leave it alone (otherwise it is cwd relative)
     const biblioPath = join(dir, biblio);
+    const absBiblioPath = isAbsolute(biblioPath)
+      ? biblioPath
+      : join(Deno.cwd(), biblioPath);
+    const ext = extname(biblioPath).toLowerCase();
     const cmd = [pandocBinaryPath()];
-    // Without -f, pandoc reads a .json input as its own JSON AST
-    if (extname(biblioPath).toLowerCase() === ".json") {
-      cmd.push("-f");
-      cmd.push("csljson");
+    let stdin: string | undefined;
+    if (ext === ".json") {
+      // Without -f, pandoc reads a .json input as its own JSON AST
+      cmd.push("-f", "csljson", absBiblioPath);
+    } else if (ext === ".yaml" || ext === ".yml") {
+      // Pandoc has no reader for a YAML bibliography: read as markdown, it
+      // only works when wrapped in --- delimiters. Like --bibliography, use
+      // the first YAML document, either a references: map or a bare array.
+      // json: true lets a duplicate key win last, as pandoc does.
+      const firstDoc = loadAll(Deno.readTextFileSync(absBiblioPath), null, {
+        schema: kBibliographyYamlSchema,
+        json: true,
+      })?.[0];
+      if (Array.isArray(firstDoc)) {
+        // --metadata-file needs a map, so wrap the array in a metadata block
+        // for pandoc's YAML reader to parse its fields as it would the map
+        cmd.push("-f", "markdown");
+        stdin = `---\n${JSON.stringify({ references: firstDoc })}\n---\n`;
+      } else {
+        cmd.push("-f", "markdown", `--metadata-file=${absBiblioPath}`);
+        stdin = "";
+      }
+    } else {
+      cmd.push(absBiblioPath);
     }
-    cmd.push(
-      isAbsolute(biblioPath) ? biblioPath : join(Deno.cwd(), biblioPath),
-    );
     cmd.push("-t");
     cmd.push("csljson");
     cmd.push("--citeproc");
@@ -105,6 +140,7 @@ export async function renderToCSLJSON(
         stderr: "piped",
         cwd: dir,
       },
+      stdin,
     );
     if (result.success) {
       if (result.stdout) {

tests/docs/smoke-all/2026/10/14/scholar-references/array-yaml.qmd

@@ -0,0 +1,15 @@
+---
+title: Scholar metadata for a top-level array YAML bibliography
+format: html
+google-scholar: true
+bibliography: references-array.yaml
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        - ['meta[name="citation_reference"][content*="citation_title=Formatted reference;"][content*="citation_volume=1.10;"][content*="citation_issue=7;"]']
+---
+
+The bibliography is a YAML file holding a top-level list of references, with no `references:` key, which pandoc accepts for `--bibliography`. The fields still go through pandoc's YAML reader: the markdown title is parsed and the unquoted volume keeps its text.
+
+This article cites one work [@cited].

tests/docs/smoke-all/2026/10/14/scholar-references/bare-yaml.qmd

@@ -0,0 +1,15 @@
+---
+title: Scholar metadata for a bare YAML bibliography
+format: html
+google-scholar: true
+bibliography: references-bare.yaml
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        - ['meta[name="citation_reference"][content*="citation_author=Alice Smith;"]']
+---
+
+The bibliography is a YAML file with a `references:` list and no `---` delimiters, which pandoc accepts for `--bibliography`. Pandoc has no input format that reads such a file, so the Scholar reference tags need it handled explicitly.
+
+This article cites one work [@cited].

tests/docs/smoke-all/2026/10/14/scholar-references/delimited-yaml.qmd

@@ -0,0 +1,15 @@
+---
+title: Scholar metadata for a delimited YAML bibliography
+format: html
+google-scholar: true
+bibliography: references-delimited.yaml
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        - ['meta[name="citation_reference"][content*="citation_title=Cited reference;"]']
+---
+
+The bibliography is a YAML file wrapped in `---` delimiters, with a duplicated `title` key. Pandoc warns and keeps the last value, so the Scholar reference tags do too.
+
+This article cites one work [@cited].

tests/docs/smoke-all/2026/10/14/scholar-references/references-array.yaml

@@ -0,0 +1,11 @@
+- id: cited
+  type: article-journal
+  title: "*Formatted* reference"
+  volume: 1.10
+  issue: !!int 7
+  author:
+  - family: Smith
+    given: Alice
+  issued:
+    date-parts:
+    - [2024]

tests/docs/smoke-all/2026/10/14/scholar-references/references-bare.yaml

@@ -0,0 +1,10 @@
+references:
+- id: cited
+  type: article-journal
+  title: Cited reference
+  author:
+  - family: Smith
+    given: Alice
+  issued:
+    date-parts:
+    - [2024]

tests/docs/smoke-all/2026/10/14/scholar-references/references-delimited.yaml

@@ -0,0 +1,13 @@
+---
+references:
+- id: cited
+  type: article-journal
+  title: Superseded title
+  title: Cited reference
+  author:
+  - family: Smith
+    given: Alice
+  issued:
+    date-parts:
+    - [2024]
+---

tests/docs/smoke-all/2026/10/14/scholar-references/references-tagged.yaml

@@ -0,0 +1,14 @@
+---
+references:
+- id: cited
+  type: article-journal
+  title: Cited reference
+  volume: !!int 2
+  issue: !custom 7
+  author:
+  - family: Smith
+    given: Alice
+  issued:
+    date-parts:
+    - [!!int 2024]
+---

tests/docs/smoke-all/2026/10/14/scholar-references/tagged-yaml.qmd

@@ -0,0 +1,15 @@
+---
+title: Scholar metadata for a YAML bibliography with explicit tags
+format: html
+google-scholar: true
+bibliography: references-tagged.yaml
+_quarto:
+  tests:
+    html:
+      ensureHtmlElements:
+        - ['meta[name="citation_reference"][content*="citation_publication_date=2024;"][content*="citation_volume=2;"][content*="citation_issue=7;"]']
+---
+
+The bibliography is a delimited YAML file whose values carry explicit tags, standard (`!!int`) and custom (`!custom`). Pandoc accepts any tag and keeps the value's text, so the Scholar reference tags do too.
+
+This article cites one work [@cited].