From 5afd7eb8a0f6ac24d1eceef173a41dd8cd26e48c Mon Sep 17 00:00:00 2001
From: Ilya Gurevich <ilya.gurevich@nytimes.com>
Date: Tue, 12 Sep 2023 12:38:42 -0400
Subject: [PATCH] simulate typing

---
 src/components/__tests__/ProseMirror.test.tsx |  58 ++++
 src/components/utils/textKeyboardSimulator.ts | 268 ++++++++++++++++++
 tsconfig.json                                 |   2 +-
 3 files changed, 327 insertions(+), 1 deletion(-)
 create mode 100644 src/components/utils/textKeyboardSimulator.ts

diff --git a/src/components/__tests__/ProseMirror.test.tsx b/src/components/__tests__/ProseMirror.test.tsx
index 6543a377..1b0041a6 100644
--- a/src/components/__tests__/ProseMirror.test.tsx
+++ b/src/components/__tests__/ProseMirror.test.tsx
@@ -12,6 +12,7 @@ import {
   teardownProseMirrorView,
 } from "../../testing/setupProseMirrorView.js";
 import { ProseMirror } from "../ProseMirror.js";
+import { simulateType } from "../utils/textKeyboardSimulator.js";
 
 describe("ProseMirror", () => {
   beforeAll(() => {
@@ -139,6 +140,63 @@ describe("ProseMirror", () => {
     expect(screen.getAllByTestId("paragraph").length).toBeGreaterThanOrEqual(1);
   });
 
+  it("supports composition events", async () => {
+    const schema = new Schema({
+      nodes: {
+        text: {},
+        paragraph: { content: "text*" },
+        doc: { content: "paragraph+" },
+      },
+    });
+    const editorState = EditorState.create({ schema });
+
+    function Paragraph({ children }: NodeViewComponentProps) {
+      return <p data-testid="paragraph">{children}</p>;
+    }
+
+    const reactNodeViews = {
+      paragraph: () => ({
+        component: Paragraph,
+        dom: document.createElement("div"),
+        contentDOM: document.createElement("span"),
+      }),
+    };
+
+    function TestEditor() {
+      const { nodeViews, renderNodeViews } = useNodeViews(reactNodeViews);
+      const [mount, setMount] = useState<HTMLDivElement | null>(null);
+
+      return (
+        <ProseMirror
+          mount={mount}
+          state={editorState}
+          dispatchTransaction={function (this: EditorView, tr) {
+            // We have to wrap the update in `act` to handle all of
+            // the async portal registering and component rendering that
+            // happens "out of band" because it's triggered by ProseMirror,
+            // not React.
+            act(() => this.updateState(this.state.apply(tr)));
+          }}
+          nodeViews={nodeViews}
+        >
+          <div data-testid="editor" ref={setMount} />
+          {renderNodeViews()}
+        </ProseMirror>
+      );
+    }
+
+    render(<TestEditor />);
+
+    const editor = screen.getByTestId("editor");
+
+    await editor.focus();
+    simulateType("ó");
+
+    expect(editor.textContent).toBe("ó");
+    // Ensure that ProseMirror really rendered our Paragraph
+    // component, not just any old <p> tag
+    expect(screen.getAllByTestId("paragraph").length).toBeGreaterThanOrEqual(1);
+  });
   afterAll(() => {
     teardownProseMirrorView();
   });
diff --git a/src/components/utils/textKeyboardSimulator.ts b/src/components/utils/textKeyboardSimulator.ts
new file mode 100644
index 00000000..05bb1554
--- /dev/null
+++ b/src/components/utils/textKeyboardSimulator.ts
@@ -0,0 +1,268 @@
+/*
+ * This simulates keypresses on an Icelandic layout keyboard. It is only
+ * intended to test composition sessions which testing-library does not support
+ * at this time. We should prefer using userEvent.type or userEvent.keyboard to
+ * this where possible.
+ *
+ * See: https://github.com/testing-library/user-event/issues/1097
+ */
+import { fireEvent } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+
+// Keyboard has been set up in the standard testing-library way in case we want
+// to use it at some point when/if they support composition sessions:
+// https://github.com/testing-library/user-event/blob/main/src/system/keyboard.ts
+const LOC_LEFT = 1;
+const LOC_RIGHT = 2;
+
+const islKeyboard = [
+  ..."0123456789".split("").map((c) => ({ code: `Digit${c}`, key: c })),
+  ...'=!"#$%&/()'
+    .split("")
+    .map((c, i) => ({ code: `Digit${i}`, key: c, shiftKey: true })),
+  ..."abcdefghijklmnopqrstuvwxyz"
+    .split("")
+    .map((c) => ({ code: `Key${c.toUpperCase()}`, key: c })),
+  ..."ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    .split("")
+    .map((c) => ({ code: `Key${c}`, key: c, shiftKey: true })),
+  { code: "Minus", key: "ö", shiftKey: false },
+  { code: "Minus", key: "Ö", shiftKey: true },
+  { code: "BracketLeft", key: "ð", shiftKey: false },
+  { code: "BracketLeft", key: "Ð", shiftKey: true },
+  { code: "Semicolon", key: "æ", shiftKey: false },
+  { code: "Semicolon", key: "Æ", shiftKey: true },
+  { code: "Slash", key: "þ", shiftKey: false },
+  { code: "Slash", key: "Þ", shiftKey: true },
+  { code: "Backslash", key: "*", shiftKey: true },
+  { code: "Backslash", key: "+", shiftKey: false },
+  { code: "BracketRight", key: "'", shiftKey: false },
+  { code: "BracketRight", key: "?", shiftKey: true },
+  { code: "Comma", key: ",", shiftKey: false },
+  { code: "Comma", key: ";", shiftKey: true },
+  { code: "Equal", key: "-", shiftKey: false },
+  { code: "Equal", key: "_", shiftKey: true },
+  { code: "IntlBackslash", key: "<", shiftKey: false },
+  { code: "IntlBackslash", key: ">", shiftKey: true },
+  { code: "Period", key: ".", shiftKey: false },
+  { code: "Period", key: ":", shiftKey: true },
+  {
+    code: "Quote",
+    key: "´",
+    shiftKey: false,
+    composing: true,
+  } /* key: 'Dead' */,
+  {
+    code: "Quote",
+    key: "´",
+    shiftKey: true,
+    composing: true,
+  } /* key: 'Dead' */,
+  { code: "Space", key: " " },
+  { code: "AltLeft", key: "Alt", location: LOC_LEFT },
+  { code: "AltRight", key: "Alt", location: LOC_RIGHT },
+  { code: "ShiftLeft", key: "Shift", location: LOC_LEFT },
+  { code: "ShiftRight", key: "Shift", location: LOC_RIGHT },
+  { code: "ControlLeft", key: "Control", location: LOC_LEFT },
+  { code: "ControlRight", key: "Control", location: LOC_RIGHT },
+  { code: "MetaLeft", key: "Meta", location: LOC_LEFT },
+  { code: "MetaRight", key: "Meta", location: LOC_RIGHT },
+  { code: "OSLeft", key: "OS", location: LOC_LEFT },
+  { code: "OSRight", key: "OS", location: LOC_RIGHT },
+  { code: "Tab", key: "Tab" },
+  { code: "CapsLock", key: "CapsLock" },
+  { code: "Backspace", key: "Backspace" },
+  { code: "Enter", key: "Enter" },
+  { code: "Escape", key: "Escape" },
+  { code: "ArrowUp", key: "ArrowUp" },
+  { code: "ArrowDown", key: "ArrowDown" },
+  { code: "ArrowLeft", key: "ArrowLeft" },
+  { code: "ArrowRight", key: "ArrowRight" },
+  { code: "Home", key: "Home" },
+  { code: "End", key: "End" },
+  { code: "Delete", key: "Delete" },
+  { code: "PageUp", key: "PageUp" },
+  { code: "PageDown", key: "PageDown" },
+  { code: "Fn", key: "Fn" },
+  { code: "Symbol", key: "Symbol" },
+  { code: "AltRight", key: "AltGraph" },
+];
+
+// a map of characters which will be split into composed keystrokes
+const decomp = {
+  á: "´a",
+  é: "´e",
+  í: "´i",
+  ó: "´o",
+  ú: "´u",
+  ý: "´y",
+};
+
+function findAllTextNodes(list: Node[], ret: Node[] = []) {
+  list.forEach((node) => {
+    if (node.nodeType === 3) {
+      ret.push(node);
+    } else if (node.nodeType === 1) {
+      findAllTextNodes([...node.childNodes], ret);
+    }
+  });
+  return ret;
+}
+
+function isText(node: Node | null): node is Text {
+  return node?.nodeType === Node.TEXT_NODE;
+}
+
+function getRangeOfPreviousChar(range0: Range | undefined) {
+  const range = range0?.cloneRange();
+  let textNode =
+    range?.startContainer.nodeType === 3 ? range?.startContainer : null;
+  if (range?.startContainer.nodeType === 1) {
+    const textNodes = findAllTextNodes(
+      [...(range?.startContainer.childNodes || [])].slice(0, range?.startOffset)
+    );
+    textNode = textNodes.pop() || null;
+  }
+  if (isText(textNode)) {
+    range?.setStart(textNode, textNode?.data.length - 1);
+  }
+  return range;
+}
+
+export function pressKey(key: string) {
+  const focusElm = document.activeElement;
+  if (!focusElm?.hasAttribute("contenteditable")) {
+    return userEvent.keyboard(key);
+  }
+
+  const isLetter = /[a-záéíóúýþæðö]/i.test(key);
+  const isShift = isLetter && key === key.toUpperCase();
+  const seq = decomp[key.toLowerCase() as keyof typeof decomp];
+
+  // use ranges for inserts?
+  const sequence = [];
+  if (isShift) {
+    sequence.push({
+      type: "keydown",
+      code: "ShiftLeft",
+      key: "Shift",
+      shiftKey: isShift,
+    });
+  }
+  if (seq) {
+    // accent key
+    const quote = { code: "Quote", key: "Dead", shiftKey: isShift };
+    sequence.push({ type: "keydown", ...quote });
+    sequence.push({ type: "compositionstart" });
+    sequence.push({ type: "compositionupdate", data: seq[0] });
+    sequence.push({ type: "input", isComposing: true });
+    sequence.push({ type: "selectionchange" });
+    sequence.push({ type: "keyup", ...quote });
+    sequence.push({ type: "keypress", ...quote });
+    // character
+    const keyData = islKeyboard.find((d) => d.key === seq[1]);
+    sequence.push({ type: "keydown", ...keyData });
+    sequence.push({ type: "compositionupdate", data: key });
+    sequence.push({ type: "compositionend" });
+    sequence.push({ type: "input", isComposing: false });
+    sequence.push({ type: "selectionchange" });
+    sequence.push({ type: "keyup", ...keyData });
+  } else {
+    const keyData = islKeyboard.find((d) => d.key === key) || {
+      key,
+      code: "Unknown",
+      shiftKey: isShift,
+    };
+    sequence.push({ type: "keydown", data: key, ...keyData });
+    sequence.push({ type: "input", isComposing: false });
+    sequence.push({ type: "selectionchange" });
+    sequence.push({ type: "keyup", ...keyData });
+  }
+  if (isShift) {
+    sequence.push({
+      type: "keyup",
+      code: "ShiftLeft",
+      key: "Shift",
+      shiftKey: isShift,
+    });
+  }
+
+  let composeSession = false;
+  let defaultPrevented = false;
+  sequence.forEach((event) => {
+    let e;
+    const { type, data } = event;
+    if (type.startsWith("key") || type === "input") {
+      e = new KeyboardEvent(type, {
+        bubbles: true,
+        cancelable: true,
+        ...event,
+      });
+    } else if (type.startsWith("composition")) {
+      e = new CompositionEvent(type, {
+        bubbles: true,
+        cancelable: true,
+        ...event,
+      });
+    } else if (type === "selectionchange") {
+      e = new Event("selectionchange", {
+        bubbles: true,
+        cancelable: true,
+        ...event,
+      });
+    } else {
+      throw new Error("Unsupported event " + type);
+    }
+    fireEvent(focusElm, e);
+    // if default was prevented during keydown, we don't add chars for this cycle
+    if (e.type === "keydown") {
+      defaultPrevented = e.defaultPrevented;
+    }
+    if (data && !defaultPrevented) {
+      // ensure we have a selection
+      const selection = document.getSelection();
+      if (!selection?.rangeCount) {
+        selection?.selectAllChildren(focusElm);
+        selection?.collapseToEnd();
+      }
+      let selectionRange = selection?.getRangeAt(0);
+      // The test env does not seem to update selection with focus
+      // in this case the selection points at <body>.
+      // We can sidestep this by setting the caret to active element
+      // if the selection container contains the active element:
+      const cAC = selectionRange?.commonAncestorContainer;
+      if (cAC?.contains(focusElm) && cAC !== focusElm) {
+        selection?.selectAllChildren(focusElm);
+        selection?.collapseToEnd();
+        selectionRange = selection?.getRangeAt(0);
+      }
+      if (composeSession) {
+        getRangeOfPreviousChar(selectionRange)?.deleteContents();
+      }
+      if (type === "compositionupdate") {
+        composeSession = false;
+      }
+      const charCode = data.charCodeAt(0);
+      if (charCode === 8) {
+        const r = selection?.isCollapsed
+          ? getRangeOfPreviousChar(selectionRange)
+          : selectionRange;
+        r?.deleteContents();
+        selection?.collapseToEnd();
+      } else if (charCode > 31) {
+        selectionRange?.deleteContents();
+        selectionRange?.insertNode(document.createTextNode(data));
+        selection?.collapseToEnd();
+      }
+    }
+  });
+}
+
+export function simulateType(text: string) {
+  text.split("").forEach(pressKey);
+}
+
+export function selectAll(node: Node) {
+  const selection = document.getSelection();
+  selection?.selectAllChildren(node);
+}
diff --git a/tsconfig.json b/tsconfig.json
index ca48256f..7724a582 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,7 @@
   "$schema": "https://json.schemastore.org/tsconfig",
   "include": ["src/**/*", "src/**/*.json"],
   "compilerOptions": {
-    "lib": ["DOM", "ES2022"],
+    "lib": ["DOM", "ES2022", "dom.iterable"],
     "target": "ES2015",
     /* Input/output paths */
     "outDir": "dist/types",