Pagination: add pageOnEmptyData option

src/Plugins/Pagination.js

@@ -183,7 +183,11 @@ class Pagination {
     let hrefs = [];
     let overrides = [];
 
-    for (let pageNumber = 0, k = items.length; pageNumber < k; pageNumber++) {
+    const totalPages =
+      items.length ? items.length : (
+        this.data.pagination.pageOnEmptyData ? 1 : 0);
+
+    for (let pageNumber = 0; pageNumber < totalPages; pageNumber++) {
       let cloned = tmpl.clone();
 
       // TODO maybe also move this permalink additions up into the pagination class

test/PaginationTest.js

@@ -44,6 +44,46 @@ test("No pagination", async (t) => {
   t.is((await paging.getPageTemplates()).length, 0);
 });
 
+test("Empty paged data", async (t) => {
+  let eleventyConfig = new TemplateConfig();
+  let tmpl = getNewTemplate(
+    "./test/stubs/paged/paged-empty.njk",
+    "./test/stubs/",
+    "./dist",
+    null,
+    null,
+    eleventyConfig
+  );
+
+  let data = await tmpl.getData();
+  let paging = new Pagination(data, tmpl.config);
+  paging.setTemplate(tmpl);
+
+  t.is(paging.getPageCount(), 0);
+  t.is(paging.pagedItems.length, 0);
+  t.is((await paging.getPageTemplates()).length, 0);
+});
+
+test("Empty paged data with pageOnEmptyData enabled", async (t) => {
+  let eleventyConfig = new TemplateConfig();
+  let tmpl = getNewTemplate(
+    "./test/stubs/paged/paged-empty-pageonemptydata.njk",
+    "./test/stubs/",
+    "./dist",
+    null,
+    null,
+    eleventyConfig
+  );
+
+  let data = await tmpl.getData();
+  let paging = new Pagination(data, tmpl.config);
+  paging.setTemplate(tmpl);
+
+  t.is(paging.getPageCount(), 0);
+  t.is(paging.pagedItems.length, 0);
+  t.is((await paging.getPageTemplates()).length, 1);
+});
+
 test("Pagination enabled in frontmatter", async (t) => {
   let eleventyConfig = new TemplateConfig();
   let tmpl = getNewTemplate(

test/stubs/paged/paged-empty-pageonemptydata.njk

@@ -0,0 +1,8 @@
+---
+pagination:
+  data: items
+  size: 1
+  pageOnEmptyData: true
+items: []
+---
+<ol>{% for item in pagination.items %}<li>{{ item }}</li>{% endfor %}</ol>

test/stubs/paged/paged-empty.njk

@@ -0,0 +1,7 @@
+---
+pagination:
+  data: items
+  size: 1
+items: []
+---
+<ol>{% for item in pagination.items %}<li>{{ item }}</li>{% endfor %}</ol>