fix(snapshot): parse the creation-cap body and refuse duplicate milestone titles

The creation-cap 200 body was projected and tested with an equality on `enabled`, so a malformed body (a quoted flag, a null) read as "no cap" and the section vanished; the body is now parsed at the boundary, so an off-shape answer fails the section with the documented-shape error. Two live milestones under one title mapped to two entries the planner would refuse on the next run; the snapshot now refuses them at read time, naming each by title and number, like the list factory and webhooks do.

Author: Vivswan

src/sections/interaction_limits/index.ts

@@ -115,6 +115,11 @@ function noLiveLimit(live: unknown): boolean {
   );
 }
 
+const LiveCreationCap = z.looseObject({
+  enabled: z.boolean(),
+  max_open_pull_requests: z.number().optional(),
+});
+
 const LiveInteractionLimit = z.looseObject({
   limit: z.string(),
   origin: z.string().optional(),
@@ -384,12 +389,14 @@ export const interactionLimitsSection = {
         `interaction_limits: ${CAP_UNAVAILABLE} (405), so pull_request_creation_cap and pull_request_creation_bypass are omitted`,
       );
     } else {
-      const liveCap = projectOntoSchema(
-        InteractionLimitsConfig.unwrap().shape.pull_request_creation_cap,
-        cap.data,
-      );
-      if (liveCap?.enabled === true) {
-        value.pull_request_creation_cap = liveCap;
+      // Parsed at the boundary: a body off the shape (a null, a quoted flag) fails the section
+      // instead of reading as "no cap".
+      const liveCap = parseLive(this, ENDPOINTS.capGet, LiveCreationCap, cap.data);
+      if (liveCap.enabled) {
+        value.pull_request_creation_cap = projectOntoSchema(
+          InteractionLimitsConfig.unwrap().shape.pull_request_creation_cap,
+          liveCap,
+        );
       }
       const bypass = await liveBypassLogins(ctx, this);
       if (bypass.length > 0) {

src/sections/milestones/index.ts

@@ -19,7 +19,11 @@ import type { SectionPermission } from "../contract/permissions.js";
 import { hasDrift, type PlannedOp, plainData, type SectionPlan } from "../contract/plan.js";
 import { rejectDuplicates } from "../contract/requests.js";
 import { knobbed } from "../shared/schema-helpers.js";
-import { knobbedSnapshot, projectOntoSchema } from "../shared/snapshot-helpers.js";
+import {
+  knobbedSnapshot,
+  projectOntoSchema,
+  rejectLiveDuplicates,
+} from "../shared/snapshot-helpers.js";
 import { MilestoneConfig } from "./schema.js";
 
 const LiveMilestone = z.looseObject({ number: z.number(), title: z.string() });
@@ -150,6 +154,13 @@ export const milestonesSection = {
     if (live.length === 0) {
       return { value: undefined, notes: [] };
     }
+    rejectLiveDuplicates(
+      this,
+      "milestone",
+      live,
+      (milestone) => milestone.title,
+      (milestone) => `${milestone.title} (number ${milestone.number})`,
+    );
     const entries = live.map((milestone) => projectOntoSchema(MilestoneConfig, milestone));
     return { value: knobbedSnapshot(this, entries), notes: [] };
   },

test/sections/snapshot-roundtrip.test.ts

@@ -9,11 +9,14 @@
 import { describe, expect, test } from "bun:test";
 import { readdirSync } from "node:fs";
 import { join } from "node:path";
+import type { GithubClient } from "../../src/github/api.js";
 import type { SectionKey } from "../../src/schema.js";
 import { actionsSecretsSection } from "../../src/sections/actions_secrets/index.js";
 import { planContext } from "../../src/sections/contract/plan.js";
 import { deployKeysSection } from "../../src/sections/deploy_keys/index.js";
+import { interactionLimitsSection } from "../../src/sections/interaction_limits/index.js";
 import { labelsSection } from "../../src/sections/labels/index.js";
+import { milestonesSection } from "../../src/sections/milestones/index.js";
 import { SECTIONS } from "../../src/sections/registry.js";
 import { webhooksSection } from "../../src/sections/webhooks/index.js";
 import { registryFake } from "./fragment-fake.js";
@@ -139,6 +142,46 @@ describe("snapshot round trip", () => {
     });
   });
 
+  test("two live milestones under one title fail the snapshot, naming both", async () => {
+    const api = registryFake({
+      milestones: [
+        { id: 1, number: 1, title: "v1", state: "open" },
+        { id: 2, number: 2, title: "v1", state: "closed" },
+      ],
+    });
+    await expect(
+      milestonesSection.snapshot(planContext(milestonesSection, api, REPO)),
+    ).rejects.toThrow(
+      'milestones: GitHub holds milestones that resolve to one identity: "v1 (number 1)" and ' +
+        '"v1 (number 2)". This section manages one milestone per identity, so the snapshot ' +
+        "cannot declare them; delete all but one of each on GitHub, then snapshot again",
+    );
+  });
+
+  test.each([
+    [{ enabled: "yes" }, "enabled: Invalid input: expected boolean, received string"],
+    [null, "(body): Invalid input: expected object, received null"],
+  ])(
+    "a creation-cap body off the shape (%j) fails the snapshot instead of reading as no cap",
+    async (body, issue) => {
+      const fake = registryFake({});
+      const api: GithubClient = {
+        tryRequest: (method, path, payload, options) =>
+          method === "GET" && path === "/repos/o/r/interaction-limits/pulls/creation-cap"
+            ? Promise.resolve({ data: body })
+            : fake.tryRequest(method, path, payload, options),
+        tryGraphql: (op, variables, slug) => fake.tryGraphql(op, variables, slug),
+      };
+      await expect(
+        interactionLimitsSection.snapshot(planContext(interactionLimitsSection, api, REPO)),
+      ).rejects.toThrow(
+        "interaction_limits: GET /repos/{owner}/{repo}/interaction-limits/pulls/creation-cap " +
+          `returned a body outside the documented shape - ${issue}. Check the "api-version" ` +
+          "input against the GitHub REST docs for this endpoint",
+      );
+    },
+  );
+
   test("a hook without a config.url is noted and left out; alone, it leaves nothing to declare", async () => {
     const api = registryFake({ hooks: [{ id: 7, config: {} }] });
     const snapshot = await webhooksSection.snapshot(planContext(webhooksSection, api, REPO));