feat: Support LaTeX and AsciiMath via MathJax on stem.excalidraw.com

src/tests/__snapshots__/linearElementEditor.test.tsx.snap

@@ -5,7 +5,8 @@ exports[`Test Linear Elements Test bound text element should match styles for te
   class="excalidraw-wysiwyg"
   data-type="wysiwyg"
   dir="auto"
-  style="position: absolute; display: inline-block; min-height: 1em; margin: 0px; padding: 0px; border: 0px; outline: 0; resize: none; background: transparent; overflow: hidden; z-index: var(--zIndex-wysiwyg); word-break: break-word; white-space: pre-wrap; overflow-wrap: break-word; box-sizing: content-box; width: 0px; height: 0px; left: 40px; top: 20px; transform: translate(0px, 0px) scale(1) rotate(0deg); text-align: center; vertical-align: middle; color: rgb(0, 0, 0); opacity: 1; filter: var(--theme-filter); max-height: -20px; font: Emoji 20px 20px; line-height: 0px; font-family: Virgil, Segoe UI Emoji;"
+  style="position: absolute; display: inline-block; min-height: 1em; margin: 0px; padding: 0px; border: 0px; outline: 0; resize: none; background: transparent; overflow: hidden; z-index: var(--zIndex-wysiwyg); word-break: break-word; white-space: pre-wrap; overflow-wrap: break-word; box-sizing: content-box; width: 0px; height: 0px; left: 40px; top: 20px; transform-origin: 0px
+          0px; transform: translate(0px, 0px) scale(1) rotate(0deg) translate(0px, 0px); text-align: center; vertical-align: middle; color: rgb(0, 0, 0); opacity: 1; filter: var(--theme-filter); max-height: -20px; font: Emoji 20px 20px; line-height: 0px; font-family: Virgil, Segoe UI Emoji;"
   tabindex="0"
   wrap="off"
 />

src/tests/customActions.test.tsx

@@ -0,0 +1,85 @@
+import { ExcalidrawElement } from "../element/types";
+import { getShortcutKey } from "../utils";
+import { API } from "./helpers/api";
+import {
+  CustomShortcutName,
+  getShortcutFromShortcutName,
+  registerCustomShortcuts,
+} from "../actions/shortcuts";
+import { Action, ActionName, DisableFn, EnableFn } from "../actions/types";
+import {
+  getActionDisablers,
+  getActionEnablers,
+  registerDisableFn,
+  registerEnableFn,
+} from "../actions/guards";
+
+const { h } = window;
+
+describe("regression tests", () => {
+  it("should retrieve custom shortcuts", () => {
+    const shortcuts: Record<CustomShortcutName, string[]> = {
+      test: [getShortcutKey("CtrlOrCmd+1"), getShortcutKey("CtrlOrCmd+2")],
+    };
+    registerCustomShortcuts(shortcuts);
+    expect(getShortcutFromShortcutName("test")).toBe("Ctrl+1");
+  });
+
+  it("should follow action guards", () => {
+    // Create the test elements
+    const text1 = API.createElement({ type: "rectangle", id: "A", y: 0 });
+    const text2 = API.createElement({ type: "rectangle", id: "B", y: 30 });
+    const text3 = API.createElement({ type: "rectangle", id: "C", y: 60 });
+    const el12: ExcalidrawElement[] = [text1, text2];
+    const el13: ExcalidrawElement[] = [text1, text3];
+    const el23: ExcalidrawElement[] = [text2, text3];
+    const el123: ExcalidrawElement[] = [text1, text2, text3];
+    // Set up the custom Action enablers
+    const enableName = "custom" as Action["name"];
+    const enabler: EnableFn = function (elements) {
+      if (elements.some((el) => el.y === 30)) {
+        return true;
+      }
+      return false;
+    };
+    registerEnableFn(enableName, enabler);
+    // Set up the standard Action disablers
+    const disableName1 = "changeFontFamily" as ActionName;
+    const disableName2 = "changeFontSize" as ActionName;
+    const disabler: DisableFn = function (elements) {
+      if (elements.some((el) => el.y === 0)) {
+        return true;
+      }
+      return false;
+    };
+    registerDisableFn(disableName1, disabler);
+    // Test the custom Action enablers
+    const enablers = getActionEnablers();
+    const isCustomEnabled = function (
+      elements: ExcalidrawElement[],
+      name: string,
+    ) {
+      return (
+        name in enablers &&
+        enablers[name].some((enabler) => enabler(elements, h.state, name))
+      );
+    };
+    expect(isCustomEnabled(el12, enableName)).toBe(true);
+    expect(isCustomEnabled(el13, enableName)).toBe(false);
+    expect(isCustomEnabled(el23, enableName)).toBe(true);
+    // Test the standard Action disablers
+    const disablers = getActionDisablers();
+    const isStandardDisabled = function (
+      elements: ExcalidrawElement[],
+      name: ActionName,
+    ) {
+      return (
+        name in disablers &&
+        disablers[name].some((disabler) => disabler(elements, h.state, name))
+      );
+    };
+    expect(isStandardDisabled(el12, disableName1)).toBe(true);
+    expect(isStandardDisabled(el23, disableName1)).toBe(false);
+    expect(isStandardDisabled(el123, disableName2)).toBe(false);
+  });
+});

src/tests/helpers/api.ts

@@ -15,7 +15,17 @@ import fs from "fs";
 import util from "util";
 import path from "path";
 import { getMimeType } from "../../data/blob";
-import { newFreeDrawElement, newImageElement } from "../../element/newElement";
+import {
+  SubtypePrepFn,
+  SubtypeRecord,
+  prepareSubtype,
+  selectSubtype,
+} from "../../subtypes";
+import {
+  maybeGetSubtypeProps,
+  newFreeDrawElement,
+  newImageElement,
+} from "../../element/newElement";
 import { Point } from "../../types";
 import { getSelectedElements } from "../../scene/selection";
 import { isLinearElementType } from "../../element/typeChecks";
@@ -25,6 +35,17 @@ const readFile = util.promisify(fs.readFile);
 const { h } = window;
 
 export class API {
+  constructor() {
+    if (true) {
+      // Call `prepareSubtype()` here for `@excalidraw/excalidraw`-specific subtypes
+    }
+  }
+
+  static addSubtype = (record: SubtypeRecord, subtypePrepFn: SubtypePrepFn) => {
+    const prep = prepareSubtype(record, subtypePrepFn);
+    return prep;
+  };
+
   static setSelectedElements = (elements: ExcalidrawElement[]) => {
     h.setState({
       selectedElementIds: elements.reduce((acc, element) => {
@@ -101,6 +122,8 @@ export class API {
     verticalAlign?: T extends "text"
       ? ExcalidrawTextElement["verticalAlign"]
       : never;
+    subtype?: ExcalidrawElement["subtype"];
+    customData?: ExcalidrawElement["customData"];
     boundElements?: ExcalidrawGenericElement["boundElements"];
     containerId?: T extends "text"
       ? ExcalidrawTextElement["containerId"]
@@ -126,6 +149,14 @@ export class API {
 
     const appState = h?.state || getDefaultAppState();
 
+    const custom = maybeGetSubtypeProps(
+      {
+        subtype: rest.subtype ?? selectSubtype(appState, type)?.subtype,
+        customData:
+          rest.customData ?? selectSubtype(appState, type)?.customData,
+      },
+      type,
+    );
     const base: Omit<
       ExcalidrawGenericElement,
       | "id"
@@ -140,6 +171,7 @@ export class API {
       | "link"
       | "updated"
     > = {
+      ...custom,
       x,
       y,
       angle: rest.angle ?? 0,

src/tests/helpers/locales/en.json

@@ -0,0 +1,7 @@
+{
+  "toolBar": {
+    "test": "Test",
+    "test2": "Test 2",
+    "test3": "Test 3"
+  }
+}

src/tests/scene/export.test.ts

@@ -8,6 +8,7 @@ import {
 
 describe("exportToSvg", () => {
   window.EXCALIDRAW_ASSET_PATH = "/";
+  window.EXCALIDRAW_EXTENSIONS_ASSET_PATH = "/";
   const ELEMENT_HEIGHT = 100;
   const ELEMENT_WIDTH = 100;
   const ELEMENTS = [

src/tests/scroll.test.tsx

@@ -6,6 +6,9 @@ import {
 } from "./test-utils";
 import { Excalidraw } from "../packages/excalidraw/index";
 import { API } from "./helpers/api";
+import { Keyboard } from "./helpers/ui";
+import { KEYS } from "../keys";
+import ExcalidrawApp from "../excalidraw-app";
 
 const { h } = window;
 
@@ -50,4 +53,33 @@ describe("appState", () => {
     });
     restoreOriginalGetBoundingClientRect();
   });
+  it("zoomed canvas scrolls on page keys", async () => {
+    mockBoundingClientRect();
+    await render(<ExcalidrawApp />, {});
+
+    const scrollTest = () => {
+      const scrollY = h.state.scrollY;
+      const pageStep = h.state.height / h.state.zoom.value;
+      // Assert the following assertions have meaning
+      expect(pageStep).toBeGreaterThan(0);
+      // Assert we scroll up
+      Keyboard.keyPress(KEYS.PAGE_UP);
+      expect(h.state.scrollY).toBe(scrollY + pageStep);
+      // Assert we scroll down
+      Keyboard.keyPress(KEYS.PAGE_DOWN);
+      Keyboard.keyPress(KEYS.PAGE_DOWN);
+      expect(h.state.scrollY).toBe(scrollY - pageStep);
+    };
+    const zoom = h.state.zoom.value;
+    // Assert we scroll properly when zoomed in
+    h.setState({ zoom: { value: (zoom * 1.1) as typeof zoom } });
+    scrollTest();
+    // Assert we scroll properly when zoomed out
+    h.setState({ zoom: { value: (zoom * 0.9) as typeof zoom } });
+    scrollTest();
+    // Assert we scroll properly with normal zoom
+    h.setState({ zoom: { value: zoom } });
+    scrollTest();
+    restoreOriginalGetBoundingClientRect();
+  });
 });

src/tests/subtypes.test.tsx

@@ -0,0 +1,598 @@
+import fallbackLangData from "./helpers/locales/en.json";
+import {
+  SubtypeRecord,
+  SubtypeMethods,
+  SubtypePrepFn,
+  addSubtypeMethods,
+  getSubtypeMethods,
+  getSubtypeNames,
+  hasAlwaysEnabledActions,
+  isValidSubtype,
+  selectSubtype,
+  subtypeCollides,
+} from "../subtypes";
+
+import { render } from "./test-utils";
+import { API } from "./helpers/api";
+import ExcalidrawApp from "../excalidraw-app";
+
+import { FontString, Theme } from "../element/types";
+import { createIcon, iconFillColor } from "../components/icons";
+import { SubtypeButton } from "../components/SubtypeButton";
+import { registerAuxLangData } from "../i18n";
+import { getFontString, getShortcutKey } from "../utils";
+import * as textElementUtils from "../element/textElement";
+import { isTextElement } from "../element";
+import { mutateElement, newElementWith } from "../element/mutateElement";
+import { AppState } from "../types";
+import { getShortcutFromShortcutName } from "../actions/shortcuts";
+
+const MW = 200;
+const TWIDTH = 200;
+const THEIGHT = 20;
+const TBASELINE = 15;
+const FONTSIZE = 20;
+const DBFONTSIZE = 40;
+const TRFONTSIZE = 60;
+
+const getLangData = async (langCode: string): Promise<Object | undefined> => {
+  try {
+    const condData = await import(
+      /* webpackChunkName: "locales/[request]" */ `./helpers/locales/${langCode}.json`
+    );
+    if (condData) {
+      return condData;
+    }
+  } catch (e) {}
+  return undefined;
+};
+
+const testSubtypeIcon = ({ theme }: { theme: Theme }) =>
+  createIcon(
+    <path
+      stroke={iconFillColor(theme)}
+      strokeWidth={2}
+      strokeLinecap="round"
+      fill="none"
+    />,
+    { width: 40, height: 20, mirror: true },
+  );
+
+const test1: SubtypeRecord = {
+  subtype: "test",
+  parents: ["line", "arrow", "rectangle", "diamond", "ellipse"],
+  disabledNames: ["changeSloppiness"],
+};
+
+const test1Button = SubtypeButton(
+  test1.subtype,
+  test1.parents[0],
+  testSubtypeIcon,
+);
+const test1NonParent = "text" as const;
+
+const test2: SubtypeRecord = {
+  subtype: "test2",
+  parents: ["text"],
+};
+
+const test2Button = SubtypeButton(
+  test2.subtype,
+  test2.parents[0],
+  testSubtypeIcon,
+);
+
+const test3: SubtypeRecord = {
+  subtype: "test3",
+  parents: ["text", "line"],
+  shortcutMap: {
+    testShortcut: [getShortcutKey("Shift+T")],
+  },
+  alwaysEnabledNames: ["test3Always"],
+};
+
+const test3Button = SubtypeButton(
+  test3.subtype,
+  test3.parents[0],
+  testSubtypeIcon,
+);
+
+const cleanTestElementUpdate = function (updates) {
+  const oldUpdates = {};
+  for (const key in updates) {
+    if (key !== "roughness") {
+      (oldUpdates as any)[key] = (updates as any)[key];
+    }
+  }
+  (updates as any).roughness = 0;
+  return oldUpdates;
+} as SubtypeMethods["clean"];
+
+const prepareNullSubtype = function () {
+  const methods = {} as SubtypeMethods;
+  methods.clean = cleanTestElementUpdate;
+  methods.measureText = measureTest2;
+  methods.wrapText = wrapTest2;
+
+  const actions = [test1Button, test2Button, test3Button];
+  return { actions, methods };
+} as SubtypePrepFn;
+
+const prepareTest1Subtype = function (
+  addSubtypeAction,
+  addLangData,
+  onSubtypeLoaded,
+) {
+  const methods = {} as SubtypeMethods;
+  methods.clean = cleanTestElementUpdate;
+
+  addLangData(fallbackLangData, getLangData);
+  registerAuxLangData(fallbackLangData, getLangData);
+
+  const actions = [test1Button];
+  actions.forEach((action) => addSubtypeAction(action));
+
+  return { actions, methods };
+} as SubtypePrepFn;
+
+const measureTest2: SubtypeMethods["measureText"] = function (
+  element,
+  next,
+  maxWidth,
+) {
+  const text = next?.text ?? element.text;
+  const customData = next?.customData ?? {};
+  const fontSize = customData.triple
+    ? TRFONTSIZE
+    : next?.fontSize ?? element.fontSize;
+  const fontFamily = element.fontFamily;
+  const fontString = getFontString({ fontSize, fontFamily });
+  const metrics = textElementUtils.measureText(text, fontString, maxWidth);
+  const width = Math.max(metrics.width - 10, 0);
+  const height = Math.max(metrics.height - 5, 0);
+  return { width, height, baseline: metrics.baseline + 1 };
+};
+
+const wrapTest2: SubtypeMethods["wrapText"] = function (
+  element,
+  maxWidth,
+  next,
+) {
+  const text = next?.text ?? element.originalText;
+  if (next?.customData && next?.customData.triple === true) {
+    return `${text.split(" ").join("\n")}\nHELLO WORLD.`;
+  }
+  if (next?.fontSize === DBFONTSIZE) {
+    return `${text.split(" ").join("\n")}\nHELLO World.`;
+  }
+  return `${text.split(" ").join("\n")}\nHello world.`;
+};
+
+const prepareTest2Subtype = function (
+  addSubtypeAction,
+  addLangData,
+  onSubtypeLoaded,
+) {
+  const methods = {
+    measureText: measureTest2,
+    wrapText: wrapTest2,
+  } as SubtypeMethods;
+
+  addLangData(fallbackLangData, getLangData);
+  registerAuxLangData(fallbackLangData, getLangData);
+
+  const actions = [test2Button];
+  actions.forEach((action) => addSubtypeAction(action));
+
+  return { actions, methods };
+} as SubtypePrepFn;
+
+const prepareTest3Subtype = function (
+  addSubtypeAction,
+  addLangData,
+  onSubtypeLoaded,
+) {
+  const methods = {} as SubtypeMethods;
+
+  addLangData(fallbackLangData, getLangData);
+  registerAuxLangData(fallbackLangData, getLangData);
+
+  const actions = [test3Button];
+  actions.forEach((action) => addSubtypeAction(action));
+
+  return { actions, methods };
+} as SubtypePrepFn;
+
+const { h } = window;
+
+describe("subtype registration", () => {
+  it("should check for invalid subtype or parents", async () => {
+    // Define invalid subtype records
+    const null1 = {} as SubtypeRecord;
+    const null2 = { subtype: "" } as SubtypeRecord;
+    const null3 = { subtype: "null" } as SubtypeRecord;
+    const null4 = { subtype: "null", parents: [] } as SubtypeRecord;
+    // Try registering the invalid subtypes
+    const prepN1 = API.addSubtype(null1, prepareNullSubtype);
+    const prepN2 = API.addSubtype(null2, prepareNullSubtype);
+    const prepN3 = API.addSubtype(null3, prepareNullSubtype);
+    const prepN4 = API.addSubtype(null4, prepareNullSubtype);
+    // Verify the guards in `prepareSubtype` worked
+    expect(prepN1).toStrictEqual({ actions: null, methods: {} });
+    expect(prepN2).toStrictEqual({ actions: null, methods: {} });
+    expect(prepN3).toStrictEqual({ actions: null, methods: {} });
+    expect(prepN4).toStrictEqual({ actions: null, methods: {} });
+  });
+  it("should return subtype actions and methods correctly", async () => {
+    // Check initial registration works
+    let prep1 = API.addSubtype(test1, prepareTest1Subtype);
+    expect(prep1.actions).toStrictEqual([test1Button]);
+    expect(prep1.methods).toStrictEqual({ clean: cleanTestElementUpdate });
+    // Check repeat registration fails
+    prep1 = API.addSubtype(test1, prepareNullSubtype);
+    expect(prep1.actions).toBeNull();
+    expect(prep1.methods).toStrictEqual({ clean: cleanTestElementUpdate });
+
+    // Check initial registration works
+    let prep2 = API.addSubtype(test2, prepareTest2Subtype);
+    expect(prep2.actions).toStrictEqual([test2Button]);
+    expect(prep2.methods).toStrictEqual({
+      measureText: measureTest2,
+      wrapText: wrapTest2,
+    });
+    // Check repeat registration fails
+    prep2 = API.addSubtype(test2, prepareNullSubtype);
+    expect(prep2.actions).toBeNull();
+    expect(prep2.methods).toStrictEqual({
+      measureText: measureTest2,
+      wrapText: wrapTest2,
+    });
+
+    // Check initial registration works
+    let prep3 = API.addSubtype(test3, prepareTest3Subtype);
+    expect(prep3.actions).toStrictEqual([test3Button]);
+    expect(prep3.methods).toStrictEqual({});
+    // Check repeat registration fails
+    prep3 = API.addSubtype(test3, prepareNullSubtype);
+    expect(prep3.actions).toBeNull();
+    expect(prep3.methods).toStrictEqual({});
+  });
+});
+
+describe("subtypes", () => {
+  it("should correctly register", async () => {
+    const subtypes = getSubtypeNames();
+    expect(subtypes).toContain(test1.subtype);
+    expect(subtypes).toContain(test2.subtype);
+    expect(subtypes).toContain(test3.subtype);
+  });
+  it("should return subtype methods", async () => {
+    expect(getSubtypeMethods(undefined)).toBeUndefined();
+    const test1Methods = getSubtypeMethods(test1.subtype);
+    expect(test1Methods?.clean).toBeDefined();
+    expect(test1Methods?.render).toBeUndefined();
+    expect(test1Methods?.wrapText).toBeUndefined();
+    expect(test1Methods?.renderSvg).toBeUndefined();
+    expect(test1Methods?.measureText).toBeUndefined();
+    expect(test1Methods?.ensureLoaded).toBeUndefined();
+  });
+  it("should not overwrite subtype methods", async () => {
+    addSubtypeMethods(test1.subtype, {});
+    addSubtypeMethods(test2.subtype, {});
+    addSubtypeMethods(test3.subtype, { clean: cleanTestElementUpdate });
+    const test1Methods = getSubtypeMethods(test1.subtype);
+    expect(test1Methods?.clean).toBeDefined();
+    const test2Methods = getSubtypeMethods(test2.subtype);
+    expect(test2Methods?.measureText).toBeDefined();
+    expect(test2Methods?.wrapText).toBeDefined();
+    const test3Methods = getSubtypeMethods(test3.subtype);
+    expect(test3Methods?.clean).toBeUndefined();
+  });
+  it("should register custom shortcuts", async () => {
+    expect(getShortcutFromShortcutName("testShortcut")).toBe("Shift+T");
+  });
+  it("should correctly validate", async () => {
+    test1.parents.forEach((p) => {
+      expect(isValidSubtype(test1.subtype, p)).toBe(true);
+      expect(isValidSubtype(undefined, p)).toBe(false);
+    });
+    expect(isValidSubtype(test1.subtype, test1NonParent)).toBe(false);
+    expect(isValidSubtype(test1.subtype, undefined)).toBe(false);
+    expect(isValidSubtype(undefined, undefined)).toBe(false);
+  });
+  it("should collide with themselves", async () => {
+    expect(subtypeCollides(test1.subtype, [test1.subtype])).toBe(true);
+    expect(subtypeCollides(test1.subtype, [test1.subtype, test2.subtype])).toBe(
+      true,
+    );
+  });
+  it("should not collide without type overlap", async () => {
+    expect(subtypeCollides(test1.subtype, [test2.subtype])).toBe(false);
+  });
+  it("should collide with type overlap", async () => {
+    expect(subtypeCollides(test1.subtype, [test3.subtype])).toBe(true);
+  });
+  it("should apply to ExcalidrawElements", async () => {
+    await render(<ExcalidrawApp />, {
+      localStorageData: {
+        elements: [
+          API.createElement({ type: "line", id: "A", subtype: test1.subtype }),
+          API.createElement({ type: "arrow", id: "B", subtype: test1.subtype }),
+          API.createElement({
+            type: "rectangle",
+            id: "C",
+            subtype: test1.subtype,
+          }),
+          API.createElement({
+            type: "diamond",
+            id: "D",
+            subtype: test1.subtype,
+          }),
+          API.createElement({
+            type: "ellipse",
+            id: "E",
+            subtype: test1.subtype,
+          }),
+        ],
+      },
+    });
+    h.elements.forEach((el) => expect(el.subtype).toBe(test1.subtype));
+  });
+  it("should enforce prop value restrictions", async () => {
+    await render(<ExcalidrawApp />, {
+      localStorageData: {
+        elements: [
+          API.createElement({
+            type: "line",
+            id: "A",
+            subtype: test1.subtype,
+            roughness: 1,
+          }),
+          API.createElement({ type: "line", id: "B", roughness: 1 }),
+        ],
+      },
+    });
+    h.elements.forEach((el) => {
+      if (el.subtype === test1.subtype) {
+        expect(el.roughness).toBe(0);
+      } else {
+        expect(el.roughness).toBe(1);
+      }
+    });
+  });
+  it("should consider enforced prop values in version increments", async () => {
+    const rectA = API.createElement({
+      type: "line",
+      id: "A",
+      subtype: test1.subtype,
+      roughness: 1,
+      strokeWidth: 1,
+    });
+    const rectB = API.createElement({
+      type: "line",
+      id: "B",
+      subtype: test1.subtype,
+      roughness: 1,
+      strokeWidth: 1,
+    });
+    // Initial element creation checks
+    expect(rectA.roughness).toBe(0);
+    expect(rectB.roughness).toBe(0);
+    expect(rectA.version).toBe(1);
+    expect(rectB.version).toBe(1);
+    // Check that attempting to set prop values not permitted by the subtype
+    // doesn't increment element versions
+    mutateElement(rectA, { roughness: 2 });
+    mutateElement(rectB, { roughness: 2, strokeWidth: 2 });
+    expect(rectA.version).toBe(1);
+    expect(rectB.version).toBe(2);
+    // Check that element versions don't increment when creating new elements
+    // while attempting to use prop values not permitted by the subtype
+    // First check based on `rectA` (unsuccessfully mutated)
+    const rectC = newElementWith(rectA, { roughness: 1 });
+    const rectD = newElementWith(rectA, { roughness: 1, strokeWidth: 1.5 });
+    expect(rectC.version).toBe(1);
+    expect(rectD.version).toBe(2);
+    // Then check based on `rectB` (successfully mutated)
+    const rectE = newElementWith(rectB, { roughness: 1 });
+    const rectF = newElementWith(rectB, { roughness: 1, strokeWidth: 1.5 });
+    expect(rectE.version).toBe(2);
+    expect(rectF.version).toBe(3);
+  });
+  it("should call custom text methods", async () => {
+    const testString = "A quick brown fox jumps over the lazy dog.";
+    await render(<ExcalidrawApp />, {
+      localStorageData: {
+        elements: [
+          API.createElement({
+            type: "text",
+            id: "A",
+            subtype: test2.subtype,
+            text: testString,
+            fontSize: FONTSIZE,
+          }),
+        ],
+      },
+    });
+    const mockMeasureText = (
+      text: string,
+      font: FontString,
+      maxWidth?: number | null,
+    ) => {
+      if (text === testString) {
+        let multiplier = 1;
+        if (font.includes(`${DBFONTSIZE}`)) {
+          multiplier = 2;
+        }
+        if (font.includes(`${TRFONTSIZE}`)) {
+          multiplier = 3;
+        }
+        const width = maxWidth
+          ? Math.min(multiplier * TWIDTH, maxWidth)
+          : multiplier * TWIDTH;
+        const height = multiplier * THEIGHT;
+        const baseline = multiplier * TBASELINE;
+        return { width, height, baseline };
+      }
+      return { width: 1, height: 0, baseline: 0 };
+    };
+
+    jest
+      .spyOn(textElementUtils, "measureText")
+      .mockImplementation(mockMeasureText);
+
+    h.elements.forEach((el) => {
+      if (isTextElement(el)) {
+        // First test with `ExcalidrawTextElement.text`
+        const metrics = textElementUtils.measureTextElement(el);
+        expect(metrics).toStrictEqual({
+          width: TWIDTH - 10,
+          height: THEIGHT - 5,
+          baseline: TBASELINE + 1,
+        });
+        const mMetrics = textElementUtils.measureTextElement(el, {}, MW);
+        expect(mMetrics).toStrictEqual({
+          width: Math.min(TWIDTH, MW) - 10,
+          height: THEIGHT - 5,
+          baseline: TBASELINE + 1,
+        });
+        const wrappedText = textElementUtils.wrapTextElement(el, MW);
+        expect(wrappedText).toEqual(
+          `${testString.split(" ").join("\n")}\nHello world.`,
+        );
+
+        // Now test with modified text in `next`
+        let next: {
+          text?: string;
+          fontSize?: number;
+          customData?: Record<string, any>;
+        } = {
+          text: "Hello world.",
+        };
+        const nextMetrics = textElementUtils.measureTextElement(el, next);
+        expect(nextMetrics).toStrictEqual({ width: 0, height: 0, baseline: 1 });
+        const nextWrappedText = textElementUtils.wrapTextElement(el, MW, next);
+        expect(nextWrappedText).toEqual("Hello\nworld.\nHello world.");
+
+        // Now test modified fontSizes in `next`
+        next = { fontSize: DBFONTSIZE };
+        const nextFM = textElementUtils.measureTextElement(el, next);
+        expect(nextFM).toStrictEqual({
+          width: 2 * TWIDTH - 10,
+          height: 2 * THEIGHT - 5,
+          baseline: 2 * TBASELINE + 1,
+        });
+        const nextFMW = textElementUtils.measureTextElement(el, next, MW);
+        expect(nextFMW).toStrictEqual({
+          width: Math.min(2 * TWIDTH, MW) - 10,
+          height: 2 * THEIGHT - 5,
+          baseline: 2 * TBASELINE + 1,
+        });
+        const nextFWrText = textElementUtils.wrapTextElement(el, MW, next);
+        expect(nextFWrText).toEqual(
+          `${testString.split(" ").join("\n")}\nHELLO World.`,
+        );
+
+        // Now test customData in `next`
+        next = { customData: { triple: true } };
+        const nextCD = textElementUtils.measureTextElement(el, next);
+        expect(nextCD).toStrictEqual({
+          width: 3 * TWIDTH - 10,
+          height: 3 * THEIGHT - 5,
+          baseline: 3 * TBASELINE + 1,
+        });
+        const nextCDMW = textElementUtils.measureTextElement(el, next, MW);
+        expect(nextCDMW).toStrictEqual({
+          width: Math.min(3 * TWIDTH, MW) - 10,
+          height: 3 * THEIGHT - 5,
+          baseline: 3 * TBASELINE + 1,
+        });
+        const nextCDWrText = textElementUtils.wrapTextElement(el, MW, next);
+        expect(nextCDWrText).toEqual(
+          `${testString.split(" ").join("\n")}\nHELLO WORLD.`,
+        );
+      }
+    });
+  });
+  it("should recognize subtypes with always-enabled actions", async () => {
+    expect(hasAlwaysEnabledActions(test1.subtype)).toBe(false);
+    expect(hasAlwaysEnabledActions(test2.subtype)).toBe(false);
+    expect(hasAlwaysEnabledActions(test3.subtype)).toBe(true);
+  });
+  it("should select active subtypes and customData", async () => {
+    const appState = {} as {
+      activeSubtypes: AppState["activeSubtypes"];
+      customData: AppState["customData"];
+    };
+
+    // No active subtypes
+    let subtypes = selectSubtype(appState, "text");
+    expect(subtypes.subtype).toBeUndefined();
+    expect(subtypes.customData).toBeUndefined();
+    // Subtype for both "text" and "line" types
+    appState.activeSubtypes = [test3.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.subtype).toBe(test3.subtype);
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.subtype).toBe(test3.subtype);
+    subtypes = selectSubtype(appState, "arrow");
+    expect(subtypes.subtype).toBeUndefined();
+    // Subtype for multiple linear types
+    appState.activeSubtypes = [test1.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.subtype).toBeUndefined();
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.subtype).toBe(test1.subtype);
+    subtypes = selectSubtype(appState, "arrow");
+    expect(subtypes.subtype).toBe(test1.subtype);
+    // Subtype for "text" only
+    appState.activeSubtypes = [test2.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.subtype).toBe(test2.subtype);
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.subtype).toBeUndefined();
+    subtypes = selectSubtype(appState, "arrow");
+    expect(subtypes.subtype).toBeUndefined();
+
+    // Test customData
+    appState.customData = {};
+    appState.customData[test1.subtype] = { test: true };
+    appState.customData[test2.subtype] = { test2: true };
+    appState.customData[test3.subtype] = { test3: true };
+    // Subtype for both "text" and "line" types
+    appState.activeSubtypes = [test3.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.customData).toBeDefined();
+    expect(subtypes.customData![test1.subtype]).toBeUndefined();
+    expect(subtypes.customData![test2.subtype]).toBeUndefined();
+    expect(subtypes.customData![test3.subtype]).toBe(true);
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.customData).toBeDefined();
+    expect(subtypes.customData![test1.subtype]).toBeUndefined();
+    expect(subtypes.customData![test2.subtype]).toBeUndefined();
+    expect(subtypes.customData![test3.subtype]).toBe(true);
+    subtypes = selectSubtype(appState, "arrow");
+    expect(subtypes.customData).toBeUndefined();
+    // Subtype for multiple linear types
+    appState.activeSubtypes = [test1.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.customData).toBeUndefined();
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.customData).toBeDefined();
+    expect(subtypes.customData![test1.subtype]).toBe(true);
+    expect(subtypes.customData![test2.subtype]).toBeUndefined();
+    expect(subtypes.customData![test3.subtype]).toBeUndefined();
+    // Multiple, non-colliding subtypes
+    appState.activeSubtypes = [test1.subtype, test2.subtype];
+    subtypes = selectSubtype(appState, "text");
+    expect(subtypes.customData).toBeDefined();
+    expect(subtypes.customData![test1.subtype]).toBeUndefined();
+    expect(subtypes.customData![test2.subtype]).toBe(true);
+    expect(subtypes.customData![test3.subtype]).toBeUndefined();
+    subtypes = selectSubtype(appState, "line");
+    expect(subtypes.customData).toBeDefined();
+    expect(subtypes.customData![test1.subtype]).toBe(true);
+    expect(subtypes.customData![test2.subtype]).toBeUndefined();
+    expect(subtypes.customData![test3.subtype]).toBeUndefined();
+  });
+});