Fixes #2654

src/TemplateLayout.js

@@ -104,24 +104,31 @@ class TemplateLayout extends TemplateContent {
     return map;
   }
 
+  async getLayoutChain() {
+    let map = await this.getTemplateLayoutMap();
+    let layoutChain = [];
+    for (let j = map.length - 1; j >= 0; j--) {
+      layoutChain.push(map[j].template.inputPath);
+    }
+    layoutChain.reverse();
+    return layoutChain;
+  }
+
   async getData() {
     if (this.dataCache) {
       return this.dataCache;
     }
 
     let map = await this.getTemplateLayoutMap();
     let dataToMerge = [];
-    let layoutChain = [];
     for (let j = map.length - 1; j >= 0; j--) {
-      layoutChain.push(map[j].template.inputPath);
       dataToMerge.push(map[j].frontMatterData);
     }
 
     // Deep merge of layout front matter
     let data = TemplateData.mergeDeep(this.config, {}, ...dataToMerge);
     delete data[this.config.keys.layout];
 
-    this.layoutChain = layoutChain.reverse();
     this.dataCache = data;
     return data;
   }

src/TemplateMap.js

@@ -374,9 +374,10 @@ class TemplateMap {
 
     this.checkForDuplicatePermalinks();
 
-    await this.config.events.emitLazy("eleventy.layouts", () =>
-      this.generateLayoutsMap()
-    );
+    await this.config.events.emitLazy("eleventy.layouts", () => {
+      // returns promise
+      return this.generateLayoutsMap();
+    });
 
     await this.config.events.emitLazy("eleventy.serverlessUrlMap", () =>
       this.generateServerlessUrlMap(orderedMap)
@@ -654,19 +655,27 @@ class TemplateMap {
     return Promise.all(promises);
   }
 
-  generateLayoutsMap() {
+  async generateLayoutsMap() {
     let layouts = {};
 
     for (let entry of this.map) {
       for (let page of entry._pages) {
         let tmpl = page.template;
-        let layout = page.data[this.config.keys.layout];
-        if (layout) {
-          let layoutFilePath = tmpl.getLayout(layout)?.inputPath;
-          if (!layouts[layoutFilePath]) {
-            layouts[layoutFilePath] = new Set();
+        let layoutKey = page.data[this.config.keys.layout];
+        if (layoutKey) {
+          let layout = tmpl.getLayout(layoutKey);
+          let layoutChain = await layout.getLayoutChain();
+          let priors = [];
+          for (let filepath of layoutChain) {
+            if (!layouts[filepath]) {
+              layouts[filepath] = new Set();
+            }
+            layouts[filepath].add(page.inputPath);
+            for (let prior of priors) {
+              layouts[filepath].add(prior);
+            }
+            priors.push(filepath);
           }
-          layouts[layoutFilePath].add(page.inputPath);
         }
       }
     }

src/Util/AsyncEventEmitter.js

@@ -30,16 +30,20 @@ class AsyncEventEmitter extends EventEmitter {
       return [];
     }
 
-    return this.emit.call(
-      this,
-      type,
-      ...args.map((arg) => {
-        if (typeof arg === "function") {
-          return arg();
+    let argsMap = [];
+    for (let arg of args) {
+      if (typeof arg === "function") {
+        let r = arg();
+        if (r instanceof Promise) {
+          r = await r;
         }
-        return arg;
-      })
-    );
+        argsMap.push(r);
+      } else {
+        argsMap.push(arg);
+      }
+    }
+
+    return this.emit.call(this, type, ...argsMap);
   }
 }
 

test/TemplateLayoutTest.js

@@ -50,7 +50,7 @@ test("Get Layout Chain", async (t) => {
 
   await tl.getData();
 
-  t.deepEqual(tl.layoutChain, [
+  t.deepEqual(await tl.getLayoutChain(), [
     "./test/stubs/_includes/layouts/layout-inherit-a.njk",
     "./test/stubs/_includes/layouts/layout-inherit-b.njk",
     "./test/stubs/_includes/layouts/layout-inherit-c.njk",
@@ -75,7 +75,7 @@ test("Get Front Matter Data", async (t) => {
     thirdinherits: "c",
   });
 
-  t.deepEqual(tl.layoutChain, [
+  t.deepEqual(await tl.getLayoutChain(), [
     "./test/stubs/_includes/layouts/layout-inherit-a.njk",
     "./test/stubs/_includes/layouts/layout-inherit-b.njk",
     "./test/stubs/_includes/layouts/layout-inherit-c.njk",

test/TemplateMapTest.js

@@ -1476,6 +1476,15 @@ test("eleventy.layouts Event", async (t) => {
       "./test/stubs-layouts-event/_includes/first.liquid": [
         "./test/stubs-layouts-event/page.md",
       ],
+      "./test/stubs-layouts-event/_includes/second.liquid": [
+        "./test/stubs-layouts-event/page.md",
+        "./test/stubs-layouts-event/_includes/first.liquid",
+      ],
+      "./test/stubs-layouts-event/_includes/third.liquid": [
+        "./test/stubs-layouts-event/page.md",
+        "./test/stubs-layouts-event/_includes/first.liquid",
+        "./test/stubs-layouts-event/_includes/second.liquid",
+      ],
     });
   });
 

test/TemplateTest.js

@@ -1819,7 +1819,7 @@ test("Get Layout Chain", async (t) => {
 
   await tmpl.getData();
 
-  t.deepEqual(tmpl._layout.layoutChain, [
+  t.deepEqual(await tmpl._layout.getLayoutChain(), [
     "./test/stubs-incremental/layout-chain/_includes/base.njk",
     "./test/stubs-incremental/layout-chain/_includes/parent.njk",
   ]);

test/stubs-layouts-event/_includes/first.liquid

@@ -1 +1,4 @@
+---
+layout: second
+---
 {{ content }}

test/stubs-layouts-event/_includes/second.liquid

@@ -0,0 +1,4 @@
+---
+layout: third.liquid
+---
+{{ content }}

test/stubs-layouts-event/_includes/third.liquid

@@ -0,0 +1 @@
+{{ content }}