1 files changed, 73 insertions, 0 deletions
diff --git a/comm/mail/base/test/browser/files/tree-element-test-common.js b/comm/mail/base/test/browser/files/tree-element-test-common.js
new file mode 100644
index 0000000000..6f22962aca
--- /dev/null
+++ b/comm/mail/base/test/browser/files/tree-element-test-common.js
@@ -0,0 +1,73 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// FIXME: Wrap the whole method around the document load listener to prevent the
+// undefined state of the "tree-view-table-row" element. This is due to the .mjs
+// nature of the class file.
+window.addEventListener("load", () => {
+  class AlternativeCardRow extends customElements.get("tree-view-table-row") {
+    static ROW_HEIGHT = 80;
+
+    connectedCallback() {
+      if (this.hasConnected) {
+        return;
+      }
+
+      super.connectedCallback();
+
+      this.cell = this.appendChild(document.createElement("td"));
+    }
+
+    get index() {
+      return super.index;
+    }
+
+    set index(index) {
+      super.index = index;
+      this.cell.textContent = this.view.getCellText(index, {
+        id: "GeneratedName",
+      });
+    }
+  }
+  customElements.define("alternative-row", AlternativeCardRow, {
+    extends: "tr",
+  });
+
+  class TestView {
+    values = [];
+
+    constructor(start, count) {
+      for (let i = start; i < start + count; i++) {
+        this.values.push(i);
+      }
+    }
+
+    get rowCount() {
+      return this.values.length;
+    }
+
+    getCellText(index, column) {
+      return `${column.id} ${this.values[index]}`;
+    }
+
+    isContainer() {
+      return false;
+    }
+
+    isContainerOpen() {
+      return false;
+    }
+
+    selectionChanged() {}
+
+    setTree() {}
+  }
+
+  const tree = document.getElementById("testTree");
+  tree.table.setBodyID("testBody");
+  tree.addEventListener("select", () => {
+    console.log("select event, selected indices:", tree.selectedIndices);
+  });
+  tree.view = new TestView(0, 150);
+});