diff --git a/packages/codemirror-blocks/spec/undo-redo-test.ts b/packages/codemirror-blocks/spec/undo-redo-test.ts
index 6284824d9..a9f770ece 100644
--- a/packages/codemirror-blocks/spec/undo-redo-test.ts
+++ b/packages/codemirror-blocks/spec/undo-redo-test.ts
@@ -1,98 +1,112 @@
 import wescheme from "../src/languages/wescheme";
-import "codemirror/addon/search/searchcursor.js";
 
 import {
-  mac,
   cmd_ctrl,
   teardown,
   mouseDown,
   keyDown,
-  insertText,
   mountCMB,
 } from "../src/toolkit/test-utils";
 import { API } from "../src/CodeMirrorBlocks";
 import { ASTNode } from "../src/ast";
+import { fireEvent } from "@testing-library/react";
 
-describe("when testing undo/redo,", () => {
-  let cmb!: API;
-
-  const currentFirstRoot = () => cmb.getAst().rootNodes[0];
-  const undo = (node?: ASTNode) => keyDown("Z", cmd_ctrl, node);
-  const redo = (node?: ASTNode) => {
-    if (mac) {
-      keyDown("Z", { metaKey: true, shiftKey: true }, node);
-    } else {
-      keyDown("Y", { ctrlKey: true }, node);
-    }
-  };
-
-  beforeEach(async () => {
-    cmb = mountCMB(wescheme).cmb;
-  });
+let cmb: API;
 
-  afterEach(teardown);
-
-  // https://github.com/bootstrapworld/codemirror-blocks/issues/315
-  // TODO(pcardune) reenable
-  xit("make sure edits can be properly undone/redone from an active block", async () => {
-    cmb.setValue(`A\nB\n`);
-    cmb.clearHistory();
-    expect(cmb.historySize()).toEqual({ undo: 0, redo: 0 });
-    mouseDown(currentFirstRoot()); // focus on the 1st root
-    keyDown(" ", {}, currentFirstRoot());
-    keyDown("X", cmd_ctrl, currentFirstRoot()); // change (1): cut first root
-    expect(cmb.getValue()).toEqual("\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
-    cmb.setCursor({ line: 2, ch: 0 });
-    keyDown("Enter"); // change (2): insert empty line
-    expect(cmb.getValue()).toEqual("\nB\n\n");
-    expect(cmb.historySize()).toEqual({ undo: 2, redo: 0 });
-    insertText("C"); // change (3): insert C at the end
-    expect(cmb.getValue()).toEqual("\nB\n\nC");
-    expect(cmb.historySize()).toEqual({ undo: 3, redo: 0 });
-    undo(currentFirstRoot()); // undo (3), leaving \nB\n\n
-    expect(cmb.getValue()).toEqual("\nB\n\n");
-    expect(cmb.historySize()).toEqual({ undo: 2, redo: 1 });
-    undo(currentFirstRoot()); // undo (2), leaving \nB\n\n
-    expect(cmb.getValue()).toEqual("\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 1, redo: 2 });
-    undo(currentFirstRoot()); // undo (1), leaving A\nB\n
-    expect(cmb.getValue()).toEqual("A\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 0, redo: 3 });
-    redo(currentFirstRoot()); // redo (1), leaving \nB\n
-    expect(cmb.getValue()).toEqual("\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 1, redo: 2 });
-    redo(currentFirstRoot()); // redo (2), leaving \nB\n\n
-    expect(cmb.getValue()).toEqual("\nB\n\n");
-    expect(cmb.historySize()).toEqual({ undo: 2, redo: 1 });
-    redo(currentFirstRoot()); // redo (3), leaving \nB\n\nC
-    expect(cmb.getValue()).toEqual("\nB\n\nC");
-    expect(cmb.historySize()).toEqual({ undo: 3, redo: 0 });
-  });
+const currentFirstRoot = () => cmb.getAst().rootNodes[0];
+const undo = (node?: ASTNode) => keyDown("Z", cmd_ctrl, node);
+const redo = (node?: ASTNode) => keyDown("Y", { ctrlKey: true }, node);
+
+beforeEach(async () => {
+  cmb = mountCMB(wescheme).cmb;
+});
+
+afterEach(teardown);
 
-  it("make sure edits can be properly undone/redone from the top level", async () => {
-    // initialize the document
-    cmb.setValue(`A\nB\n`);
-    cmb.clearHistory();
-    expect(cmb.historySize()).toEqual({ undo: 0, redo: 0 });
-
-    // change (1): cut first root
-    mouseDown(currentFirstRoot()); // focus on the 1st root
-    keyDown(" ", {}, currentFirstRoot());
-    keyDown("X", cmd_ctrl, currentFirstRoot());
-    expect(cmb.getValue()).toEqual("\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
-
-    // initiate undo from the top-level
-    cmb.setCursor({ line: 1, ch: 0 });
-    undo();
-    expect(cmb.getValue()).toEqual("A\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 0, redo: 1 });
-
-    // initiate redo from the top-level
-    cmb.setCursor({ line: 1, ch: 0 });
-    redo();
-    expect(cmb.getValue()).toEqual("\nB\n");
-    expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
+// https://github.com/bootstrapworld/codemirror-blocks/issues/315
+it("make sure edits can be properly undone/redone from an active block", () => {
+  // initialize state
+  cmb.setValue(`A\nB\n`);
+  cmb.clearHistory();
+  expect(cmb.historySize()).toEqual({ undo: 0, redo: 0 });
+
+  // change (1): cut first root
+  mouseDown(currentFirstRoot()); // focus on the 1st root
+  keyDown(" ", {}, currentFirstRoot());
+  keyDown("X", cmd_ctrl, currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
+
+  // change (2): insert empty line
+  cmb.setCursor({ line: 2, ch: 0 });
+  keyDown("Enter");
+  expect(cmb.getValue()).toEqual("\nB\n\n");
+  expect(cmb.historySize()).toEqual({ undo: 2, redo: 0 });
+
+  // change (3): insert C at the end
+  fireEvent.keyPress(document.activeElement!, {
+    key: "C",
+    code: "KeyC",
+    charCode: 67,
   });
+  keyDown("Enter");
+
+  expect(cmb.getValue()).toEqual("\nB\n\nC");
+  expect(cmb.historySize()).toEqual({ undo: 3, redo: 0 });
+
+  // undo (3), leaving \nB\n\n
+  undo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n\n");
+  expect(cmb.historySize()).toEqual({ undo: 2, redo: 1 });
+
+  // undo (2), leaving \nB\n\n
+  undo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 1, redo: 2 });
+
+  // undo (1), leaving A\nB\n
+  undo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("A\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 0, redo: 3 });
+
+  // redo (1), leaving \nB\n
+  redo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 1, redo: 2 });
+
+  // redo (2), leaving \nB\n\n
+  redo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n\n");
+  expect(cmb.historySize()).toEqual({ undo: 2, redo: 1 });
+
+  // redo (3), leaving \nB\n\nC
+  redo(currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n\nC");
+  expect(cmb.historySize()).toEqual({ undo: 3, redo: 0 });
+});
+
+it("make sure edits can be properly undone/redone from the top level", () => {
+  // initialize the document
+  cmb.setValue(`A\nB\n`);
+  cmb.clearHistory();
+  expect(cmb.historySize()).toEqual({ undo: 0, redo: 0 });
+
+  // change (1): cut first root
+  mouseDown(currentFirstRoot()); // focus on the 1st root
+  keyDown(" ", {}, currentFirstRoot());
+  keyDown("X", cmd_ctrl, currentFirstRoot());
+  expect(cmb.getValue()).toEqual("\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
+
+  // initiate undo from the top-level
+  cmb.setCursor({ line: 1, ch: 0 });
+  undo();
+  expect(cmb.getValue()).toEqual("A\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 0, redo: 1 });
+
+  // initiate redo from the top-level
+  cmb.setCursor({ line: 1, ch: 0 });
+  redo();
+  expect(cmb.getValue()).toEqual("\nB\n");
+  expect(cmb.historySize()).toEqual({ undo: 1, redo: 0 });
 });