import { describe, expect, it } from "@effect/vitest"; import {  COMPOSER_MENTION_DRAG_TYPE,  type ComposerMentionDropHost,  composerMentionFromTreePath,  dataTransferHasComposerMention,  makeComposerMentionDragHandlers,} from "./composerMentionDrag.ts"; const makeDragEvent = (options?: { mention?: string; types?: ReadonlyArray<string> }) => {  const mention = options?.mention ?? "[index.md](docs/index.md)";  const calls: Array<string> = [];  const event = {    dataTransfer: {      types: options?.types ?? [COMPOSER_MENTION_DRAG_TYPE, "text/plain"],      getData: (format: string) => (format === COMPOSER_MENTION_DRAG_TYPE ? mention : ""),      dropEffect: "none",    },    nativeEvent: {      stopPropagation: () => void calls.push("nativeStopPropagation"),    },    preventDefault: () => void calls.push("preventDefault"),    stopPropagation: () => void calls.push("stopPropagation"),  };  return { event, calls };}; const makeHost = (insertResult = true) => {  const log: Array<string> = [];  const host: ComposerMentionDropHost = {    insertMentionAtEnd: (text) => {      log.push(`insert:${text}`);      return insertResult;    },    setDragActive: (active) => void log.push(`active:${active}`),    onInsertRejected: () => void log.push("rejected"),  };  return { host, log };}; describe("composerMentionFromTreePath", () => {  it("serializes a file path into a mention", () => {    expect(composerMentionFromTreePath("docs/index.md")).toBe("[index.md](docs/index.md)");  });   it("strips the trailing slash directory rows carry", () => {    expect(composerMentionFromTreePath("docs/architecture/")).toBe(      "[architecture](docs/architecture)",    );  });   it("rejects drags that carry no path", () => {    expect(composerMentionFromTreePath("")).toBeNull();    expect(composerMentionFromTreePath("/")).toBeNull();  });}); describe("dataTransferHasComposerMention", () => {  it("detects the mention payload among drag types", () => {    expect(dataTransferHasComposerMention([COMPOSER_MENTION_DRAG_TYPE, "text/plain"])).toBe(true);    expect(dataTransferHasComposerMention(["Files"])).toBe(false);    expect(dataTransferHasComposerMention([])).toBe(false);  });}); describe("makeComposerMentionDragHandlers", () => {  it("leaves drags without the mention payload alone", () => {    const { host, log } = makeHost();    const handlers = makeComposerMentionDragHandlers(host);    const { event, calls } = makeDragEvent({ types: ["Files"] });    handlers.onDragEnter(event);    handlers.onDragOver(event);    handlers.onDrop(event);    expect(calls).toEqual([]);    expect(log).toEqual([]);  });   it("stops the native event too, not just the synthetic one", () => {    // React's stopPropagation only halts synthetic dispatch; without the    // native stop, the editor's own DOM listeners process the drop and sync    // their stale state back over the inserted mention.    const { host } = makeHost();    const handlers = makeComposerMentionDragHandlers(host);    const { event, calls } = makeDragEvent();    handlers.onDrop(event);    expect(calls).toContain("preventDefault");    expect(calls).toContain("stopPropagation");    expect(calls).toContain("nativeStopPropagation");  });   it('answers dragover with the "move" effect the tree allows', () => {    // Naming an effect outside the source's effectAllowed makes the browser    // cancel the drop without ever firing it.    const { host } = makeHost();    const handlers = makeComposerMentionDragHandlers(host);    const { event } = makeDragEvent();    handlers.onDragOver(event);    expect(event.dataTransfer.dropEffect).toBe("move");  });   it("inserts the mention with its trailing space and clears the highlight", () => {    const { host, log } = makeHost();    const handlers = makeComposerMentionDragHandlers(host);    handlers.onDragEnter(makeDragEvent().event);    handlers.onDrop(makeDragEvent().event);    expect(log).toEqual(["active:true", "active:false", "insert:[index.md](docs/index.md) "]);  });   it("reports a rejected insert instead of failing silently", () => {    const { host, log } = makeHost(false);    const handlers = makeComposerMentionDragHandlers(host);    handlers.onDrop(makeDragEvent().event);    expect(log).toContain("rejected");  });   it("ignores a drop whose payload is empty", () => {    const { host, log } = makeHost();    const handlers = makeComposerMentionDragHandlers(host);    handlers.onDrop(makeDragEvent({ mention: "" }).event);    expect(log).toEqual(["active:false"]);  });});