fix(model-capabilities): harden canonical alias guardrails

src/shared/model-capability-guardrails.test.ts

@@ -0,0 +1,92 @@
+import { describe, expect, test } from "bun:test"
+
+import type { ModelCapabilitiesSnapshot } from "./model-capabilities"
+import { getBundledModelCapabilitiesSnapshot } from "./model-capabilities"
+import {
+  collectModelCapabilityGuardrailIssues,
+  getBuiltInRequirementModelIDs,
+} from "./model-capability-guardrails"
+
+describe("model-capability-guardrails", () => {
+  test("keeps the current alias registry and built-in requirements aligned with the bundled snapshot", () => {
+    const issues = collectModelCapabilityGuardrailIssues()
+
+    expect(issues).toEqual([])
+  })
+
+  test("requires built-in requirement models to stay unique and sorted", () => {
+    const modelIDs = getBuiltInRequirementModelIDs()
+
+    expect(modelIDs).toEqual([...modelIDs].sort())
+    expect(new Set(modelIDs).size).toBe(modelIDs.length)
+    expect(modelIDs).toContain("claude-opus-4-6")
+    expect(modelIDs).toContain("gpt-5.4")
+    expect(modelIDs).toContain("kimi-k2.5")
+  })
+
+  test("flags exact aliases whose canonical target disappears from the snapshot", () => {
+    const bundledSnapshot = getBundledModelCapabilitiesSnapshot()
+    const brokenSnapshot: ModelCapabilitiesSnapshot = {
+      ...bundledSnapshot,
+      models: Object.fromEntries(
+        Object.entries(bundledSnapshot.models).filter(([modelID]) => modelID !== "gemini-3.1-pro-preview"),
+      ),
+    }
+
+    const issues = collectModelCapabilityGuardrailIssues({
+      snapshot: brokenSnapshot,
+      requirementModelIDs: [],
+    })
+
+    expect(issues).toContainEqual(
+      expect.objectContaining({
+        kind: "alias-target-missing-from-snapshot",
+        aliasModelID: "gemini-3.1-pro-high",
+        canonicalModelID: "gemini-3.1-pro-preview",
+      }),
+    )
+  })
+
+  test("flags exact aliases when models.dev gains a canonical entry for the alias itself", () => {
+    const bundledSnapshot = getBundledModelCapabilitiesSnapshot()
+    const aliasCollisionSnapshot: ModelCapabilitiesSnapshot = {
+      ...bundledSnapshot,
+      models: {
+        ...bundledSnapshot.models,
+        "gemini-3.1-pro-high": {
+          id: "gemini-3.1-pro-high",
+          family: "gemini",
+          reasoning: true,
+        },
+      },
+    }
+
+    const issues = collectModelCapabilityGuardrailIssues({
+      snapshot: aliasCollisionSnapshot,
+      requirementModelIDs: [],
+    })
+
+    expect(issues).toContainEqual(
+      expect.objectContaining({
+        kind: "exact-alias-collides-with-snapshot",
+        aliasModelID: "gemini-3.1-pro-high",
+        canonicalModelID: "gemini-3.1-pro-preview",
+      }),
+    )
+  })
+
+  test("flags built-in requirement models that rely on aliases instead of canonical IDs", () => {
+    const issues = collectModelCapabilityGuardrailIssues({
+      requirementModelIDs: ["gemini-3.1-pro-high"],
+    })
+
+    expect(issues).toContainEqual(
+      expect.objectContaining({
+        kind: "built-in-model-relies-on-alias",
+        modelID: "gemini-3.1-pro-high",
+        canonicalModelID: "gemini-3.1-pro-preview",
+        ruleID: "gemini-3.1-pro-tier-alias",
+      }),
+    )
+  })
+})