refactor(core): slice model references at the first slash (#46467)

packages/core/src/model.ts

@@ -38,10 +38,10 @@ export function compatibility(input: unknown): Compatibility | undefined {
 }
 
 export function parse(input: string): { providerID: Provider.ID; modelID: ID } {
-  const [providerID, ...modelID] = input.split("/")
+  const index = input.indexOf("/")
   return {
-    providerID: Provider.ID.make(providerID),
-    modelID: ID.make(modelID.join("/")),
+    providerID: Provider.ID.make(index === -1 ? input : input.slice(0, index)),
+    modelID: ID.make(index === -1 ? "" : input.slice(index + 1)),
   }
 }
 

packages/core/test/model.test.ts

@@ -5,6 +5,23 @@ import { Provider } from "@opencode-ai/core/provider"
 
 const decode = Schema.decodeUnknownSync(Model.Ref)
 
+describe("Model.parse", () => {
+  test.each([
+    ["vendor/model", "vendor", "model"],
+    ["vendor/team/model", "vendor", "team/model"],
+    ["vendor", "vendor", ""],
+    ["", "", ""],
+    ["/model", "", "model"],
+    ["vendor/", "vendor", ""],
+    ["vendor//model/", "vendor", "/model/"],
+  ])("parses %j at the first slash", (input, providerID, modelID) => {
+    expect(Model.parse(input)).toEqual({
+      providerID: Provider.ID.make(providerID),
+      modelID: Model.ID.make(modelID),
+    })
+  })
+})
+
 describe("Model.Ref", () => {
   test("accepts a model selection without a variant", () => {
     expect(decode({ id: "claude-sonnet", providerID: "anthropic" })).toEqual({