test(editor): add integration tests for slash menu, mention menu, and drag reorder

- Verify /Heading 1 inserts "# " markdown via buildSlashGroups + onSelect
- Verify [[ mention selects first page and inserts "[[Getting Started]]"
- Verify drag block 1 to position 3 reorders correctly and is reversible

packages/editor/src/components/__tests__/editor-integration.test.ts

@@ -4,6 +4,8 @@ import { EditorState } from "prosemirror-state"
 import { EditorView } from "prosemirror-view"
 import type { PatternOpenPayload } from "@/composables/usePatternPlugin"
 import {
+  buildMentionGroups,
+  buildSlashGroups,
   useMentionGroups,
   useSlashGroups,
 } from "@/composables/useSuggestionGroups"
@@ -387,3 +389,88 @@ function stableId(prefix: string): () => string {
   let n = 0
   return () => `${prefix}-${n++}`
 }
+
+describe("suggestion menu selection", () => {
+  it("slash command Heading 1 inserts # markdown syntax", () => {
+    const respond = vi.fn()
+    const closeSession = vi.fn()
+    const onClose = vi.fn()
+
+    const payload: PatternOpenPayload = {
+      kind: "command",
+      trigger: "/",
+      query: "/he",
+      position: { x: 0, y: 0 },
+      range: { from: 0, to: 3 },
+      respond,
+      close: closeSession,
+    }
+
+    const groups = buildSlashGroups(payload, null, onClose)
+    const heading1 = groups
+      .flatMap((g) => g.items ?? [])
+      .find((item) => item.label === "Heading 1")
+
+    expect(heading1).toBeDefined()
+    heading1!.onSelect()
+
+    expect(respond).toHaveBeenCalledWith({ text: "# ", mode: "replace" })
+    expect(closeSession).toHaveBeenCalledWith("completed")
+    expect(onClose).toHaveBeenCalled()
+  })
+
+  it("[[ mention menu selects page and inserts [[Page Name]]", () => {
+    const respond = vi.fn()
+    const closeSession = vi.fn()
+    const onClose = vi.fn()
+
+    const payload: PatternOpenPayload = {
+      kind: "reference",
+      trigger: "[[",
+      query: "[[Page",
+      position: { x: 0, y: 0 },
+      range: { from: 0, to: 7 },
+      respond,
+      close: closeSession,
+    }
+
+    const groups = buildMentionGroups(payload, onClose)
+    const firstPage = groups
+      .flatMap((g) => g.items ?? [])
+      .find((item: any) => item.suffix === "Page")
+
+    expect(firstPage).toBeDefined()
+    expect(groups[0].id).toBe("pages")
+    firstPage!.onSelect()
+
+    expect(respond).toHaveBeenCalledWith({
+      text: "[[Getting Started]]",
+      mode: "replace",
+    })
+    expect(closeSession).toHaveBeenCalledWith("completed")
+    expect(onClose).toHaveBeenCalled()
+  })
+
+  it("drag block 1 to position 3 reorders correctly", () => {
+    const blocks = [
+      { id: "a", depth: 0, content: "first" },
+      { id: "b", depth: 1, content: "second" },
+      { id: "c", depth: 2, content: "third" },
+      { id: "d", depth: 0, content: "fourth" },
+    ]
+
+    // Drag block at index 1 ("second") to index 3
+    const reordered = moveBlock(blocks, 1, 3)
+    expect(reordered[0].id).toBe("a")
+    expect(reordered[1].id).toBe("c")
+    expect(reordered[2].id).toBe("d")
+    expect(reordered[3].id).toBe("b")
+
+    // Undo — drag back from 3 to 1
+    const restored = moveBlock(reordered, 3, 1)
+    expect(restored[0].id).toBe("a")
+    expect(restored[1].id).toBe("b")
+    expect(restored[2].id).toBe("c")
+    expect(restored[3].id).toBe("d")
+  })
+})