fix(tui): include variant in model switch notice (#34856)

Co-authored-by: Aiden Cline <aidenpcline@gmail.com>

Author: opencode-agent[bot]

packages/tui/src/routes/session/index.tsx

@@ -71,6 +71,7 @@ import { OPENCODE_BASE_MODE, useBindings, useCommandShortcut } from "../../keyma
 import { usePathFormatter } from "../../context/path-format"
 import { LocationProvider } from "../../context/location"
 import { createSessionRows, type PartRef, type SessionRow } from "./rows"
+import { switchLabel } from "../../util/model"
 
 addDefaultParsers(parsers.parsers)
 
@@ -1231,8 +1232,7 @@ function SessionSwitchMessageV2(props: { message: SessionMessage }) {
   const { theme } = useTheme()
   const text = () => {
     if (props.message.type === "agent-switched") return `Switched agent to ${props.message.agent}`
-    if (props.message.type === "model-switched")
-      return `Switched model to ${props.message.model.providerID}/${props.message.model.id}`
+    if (props.message.type === "model-switched") return switchLabel(props.message.model)
     return ""
   }
   return <text fg={theme.textMuted}>{text()}</text>

packages/tui/src/util/model.ts

@@ -26,3 +26,11 @@ export function name(
 ) {
   return get(list, providerID, modelID)?.name ?? modelID
 }
+
+export function formatRef(model: { providerID: string; id: string; variant?: string }) {
+  return [model.providerID, model.id, model.variant].filter((value) => value !== undefined).join("/")
+}
+
+export function switchLabel(model: { providerID: string; id: string; variant?: string }) {
+  return `Switched model to ${formatRef(model)}`
+}

packages/tui/test/util/model.test.ts

@@ -1,9 +1,20 @@
 import { describe, expect, test } from "bun:test"
-import { parse } from "../../src/util/model"
+import { formatRef, parse, switchLabel } from "../../src/util/model"
 
 describe("util.model", () => {
   test("splits provider from a nested model identifier", () => {
     expect(parse("provider/org/model")).toEqual({ providerID: "provider", modelID: "org/model" })
     expect(parse("invalid")).toEqual({ providerID: "invalid", modelID: "" })
   })
+
+  test("includes the selected variant in model refs", () => {
+    expect(formatRef({ providerID: "anthropic", id: "sonnet", variant: "thinking" })).toBe("anthropic/sonnet/thinking")
+    expect(formatRef({ providerID: "anthropic", id: "sonnet" })).toBe("anthropic/sonnet")
+  })
+
+  test("includes the selected variant in model switch notices", () => {
+    expect(switchLabel({ providerID: "anthropic", id: "sonnet", variant: "thinking" })).toBe(
+      "Switched model to anthropic/sonnet/thinking",
+    )
+  })
 })