test(mcp-server): selection requests, get_selection texts, and page screenshots that leave the view alone

Unit tests for the request plumbing (random id, one answer, timeout), the tool's texts (cells, nothing selected, external draw.io) and the shell's side (one answer per request, after draw.io is up, never during a projection); the wiring test starts a session with BROWSER=none to see the no-tab message. Shell e2e: cells selected in the editor reach get_selection; a PNG of another page differs from the page on screen, which stays.
2026-10-13 04:59:51 +08:00 · 2026-10-11 20:56:07 +09:00
parent b3dcd91f54
commit af842ac287
5 changed files with 455 additions and 4 deletions
@@ -243,6 +243,83 @@ test("exporting another page shows it for a moment, then the user's page comes b
    expect(xml).toContain('name="Second"')
 })

+test("a screenshot of another page leaves the page on screen alone", async ({
+    page,
+}) => {
+    const frame = await openShell(page)
+    await toolText("create_new_diagram", { xml: box("2", "Front page", 40) })
+    await expect(frame.getByText("Front page")).toBeVisible({ timeout: 10_000 })
+    await toolText("add_page", {
+        name: "Backside",
+        xml: `<mxGraphModel><root><mxCell id="0"/><mxCell id="1" parent="0"/><mxCell id="b1" value="OnBack" style="rounded=1;" vertex="1" parent="1"><mxGeometry x="40" y="40" width="120" height="60" as="geometry"/></mxCell></root></mxGraphModel>`,
+    })
+    const tabs = frame.locator(".geTabContainer")
+    await expect(tabs.getByText("Backside", { exact: true })).toBeVisible({
+        timeout: 10_000,
+    })
+    const activeTab = tabs.locator(".geActivePage")
+    await expect(activeTab).toHaveText("Page-1")
+    // The page on screen, as the editor reports it to the server
+    const before = await toolText("get_selection")
+    expect(before).toContain('page "Page-1"')
+
+    // PNG: draw.io renders the other page by its id, off screen; the shell
+    // never shows it as a projection, so the page on screen does not change
+    const png = async (args: Record<string, unknown>) => {
+        const result = await client.callTool({
+            name: "screenshot_diagram",
+            arguments: args,
+        })
+        const image = (
+            result.content as {
+                type: string
+                data?: string
+                mimeType?: string
+            }[]
+        ).find((c) => c.type === "image")
+        expect(result.isError ?? false).toBe(false)
+        expect(image?.mimeType).toBe("image/png")
+        expect(image?.data?.length ?? 0).toBeGreaterThan(1000)
+        return image?.data ?? ""
+    }
+    const back = await png({ page_name: "Backside" })
+    await expect(activeTab).toHaveText("Page-1")
+    await expect(frame.getByText("Front page")).toBeVisible()
+    expect(await toolText("get_selection")).toContain('page "Page-1"')
+    // Another picture than the page on screen
+    expect(await png({})).not.toBe(back)
+})
+
+test("get_selection reports the cells selected in the editor", async ({
+    page,
+}) => {
+    const frame = await openShell(page)
+    await toolText("create_new_diagram", {
+        xml: `${box("2", "Pick me", 40)}\n${box("3", "Leave me", 240)}\n<mxCell id="4" value="link" source="2" target="3"/>`,
+    })
+    await expect(frame.getByText("Pick me")).toBeVisible({ timeout: 10_000 })
+    const nothing = await toolText("get_selection")
+    expect(nothing).toContain("Nothing is selected")
+    expect(nothing).toContain('page "Page-1"')
+
+    // Select a shape and the edge in the editor, as a click would
+    await frame.locator("body").evaluate((body) => {
+        const w = body.ownerDocument.defaultView as any
+        w.Draw.loadPlugin((ui: any) => {
+            const graph = ui.editor.graph
+            graph.setSelectionCells([
+                graph.model.getCell("2"),
+                graph.model.getCell("4"),
+            ])
+        })
+    })
+    const text = await toolText("get_selection")
+    expect(text).toContain('2 cells selected on page "Page-1"')
+    expect(text).toContain('id="2" shape "Pick me" at x=40 y=40 w=120 h=60')
+    expect(text).toContain('id="4" edge "link" from "2" to "3"')
+    expect(text).not.toContain('id="3"')
+})
+
 // --- Version cards from the server's History (shell/node-versions-source.ts) ---

 test("the version cards follow the server's History; undo, redo and restore go through it", async ({