fix: extend filter path resolution to support at/path filters from extensions

news/changelog-1.8.md

@@ -72,6 +72,7 @@ All changes included in 1.8:
 - ([#12727](https://github.com/quarto-dev/quarto-cli/issues/12727)): Do not crash in the presence of malformed tabset contents.
 - ([#12806](https://github.com/quarto-dev/quarto-cli/pull/12806)): Use pandoc APIs to handle codepage conversion on Windows.
 - ([#12811](https://github.com/quarto-dev/quarto-cli/pull/12811)): Add support for YouTube Shorts in `video` shortcode.
+- ([#11750](https://github.com/quarto-dev/quarto-cli/pull/11750)): Extend filter path resolution to support `at`/`path` filters from extensions.
 
 ## Commands
 

src/command/render/filters.ts

@@ -851,19 +851,28 @@ async function resolveFilterExtension(
   // Resolve any filters that are provided by an extension
   const results: (QuartoFilter | QuartoFilter[])[] = [];
   const getFilter = async (filter: QuartoFilter) => {
-    // Look for extension names in the filter list and result them
+    // Look for extension names in the filter list and resolve them
     // into the filters provided by the extension
-    if (
-      filter !== kQuartoFilterMarker && filter !== kQuartoCiteProcMarker &&
-      typeof filter === "string"
-    ) {
+    if (filter === kQuartoFilterMarker || filter === kQuartoCiteProcMarker) {
+      return filter;
+    }
+
+    let pathToResolve: string | null = null;
+
+    if (typeof filter === "string") {
+      pathToResolve = filter;
+    } else if (typeof filter === "object" && filter.path) {
+      pathToResolve = filter.path;
+    }
+
+    if (pathToResolve) {
       // The filter string points to an executable file which exists
-      if (existsSync(filter) && !Deno.statSync(filter).isDirectory) {
+      if (existsSync(pathToResolve) && !Deno.statSync(pathToResolve).isDirectory) {
         return filter;
       }
 
       const extensions = await options.services.extension?.find(
-        filter,
+        pathToResolve,
         options.source,
         "filters",
         options.project?.config,
@@ -873,15 +882,35 @@ async function resolveFilterExtension(
       // Filter this list of extensions
       const filteredExtensions = filterExtensions(
         extensions || [],
-        filter,
+        pathToResolve,
         "filter",
       );
       // Return any contributed plugins
       if (filteredExtensions.length > 0) {
         // This matches an extension, use the contributed filters
-        const filters = extensions[0].contributes.filters;
-        if (filters) {
-          return filters;
+        const extensionFilters = extensions[0].contributes.filters;
+        if (extensionFilters) {
+          // After "path" resolution, "at" needs to be preserved
+          if (typeof filter === "string") {
+            return extensionFilters;
+          } else if (isFilterEntryPoint(filter)) {
+            return extensionFilters.map(extFilter => {
+              if (typeof extFilter === "string") {
+                return {
+                  type: extFilter.endsWith(".lua") ? "lua" : "json" as "lua" | "json",
+                  path: extFilter,
+                  at: filter.at
+                };
+              } else {
+                return {
+                  ...extFilter,
+                  at: filter.at
+                };
+              }
+            });
+          } else {
+            return extensionFilters;
+          }
         } else {
           return filter;
         }

tests/docs/smoke-all/2025/07/13/11750.qmd

@@ -0,0 +1,24 @@
+---
+title: "Issue 11750"
+format: html
+filters:
+  - path: cite
+    at: post-quarto
+_quarto:
+  tests:
+    html:
+      ensureFileRegexMatches:
+        - 
+          - '<p><a href="#fig-test" class="quarto-xref">Figure&nbsp;1</a></p>'
+          - '<p><a href="https://github.com/mcanouil">@mcanouil</a></p>'
+---
+
+::: {#fig-test}
+Not a figure
+
+But a caption
+:::
+
+@fig-test
+
+@mcanouil

tests/docs/smoke-all/2025/07/13/_extensions/cite/_extension.yml

@@ -0,0 +1,7 @@
+title: Cite
+author: Mickaël Canouil
+version: 1.0.0
+quarto-required: ">=1.8.0"
+contributes:
+  filters:
+    - cite.lua

tests/docs/smoke-all/2025/07/13/_extensions/cite/cite.lua

@@ -0,0 +1,3 @@
+function Cite(cite)
+  return pandoc.Link(cite.content, "https://github.com/" .. cite.content[1].text:sub(2))
+end