docs(readme): replace the non-null assertion in the usage example

.github/workflows/ci.yml

@@ -43,8 +43,13 @@ jobs:
       - name: Typecheck
         run: pnpm typecheck
 
-      - name: Test
-        run: pnpm test
+      - name: Test with coverage gate
+        # vitest.config.ts enforces 100% statements/branches/functions/lines: the run exits non-zero below any threshold, so this step IS the coverage gate rather than a report-only pass.
+        run: pnpm test:coverage
+
+      - name: Mutation gate
+        # stryker.config.ts enforces a 100% mutation score (thresholds.break): any surviving mutant in src/domain or src/schemas fails the build.
+        run: pnpm test:mutation
 
       - name: Build
         run: pnpm build

README.md

@@ -42,9 +42,11 @@ peer.on("message", (m) => console.log(`${m.fromName ?? m.from}: ${m.body}`));
 peer.on("receipt", (r) => console.log(`status: ${r.status}`));
 
 const sessions = await peer.roster();
-const { msgId } = await peer.send(sessions[0]!.pid, "hello from my app");
-
-await peer.subscribeIdle(sessions[0]!.pid);
+const first = sessions.find((s) => s.name === "claude");
+if (first !== undefined) {
+  const { msgId } = await peer.send({ pid: first.pid }, "hello from my app");
+  await peer.subscribeIdle({ pid: first.pid });
+}
 peer.on("idle", (n) => console.log(`session ${n.state}`));
 
 // …later

eslint.config.ts

@@ -1,6 +1,31 @@
 import { exadevConfig } from "@exadev/eslint-config";
 import eslintPluginPrettierRecommended from "eslint-plugin-prettier/recommended";
 import globals from "globals";
+import type { Rule } from "eslint";
+
+/**
+ * Bans mutation-exemption comments in any form (the "Stryker" + "disable" pair, case-insensitive). The mutation score is gated at 100% (stryker.config.ts), so exempting a mutant anywhere is a silent hole in that gate: the ban keeps the score honest by forcing an unkilled mutant to be either killed by a test or fixed in the design, never waived by a comment.
+ */
+const noStrykerDisable: Rule.RuleModule = {
+  create(context) {
+    const comments = context.sourceCode.getAllComments();
+    for (const comment of comments) {
+      const loc = comment.loc;
+      if (
+        loc !== undefined &&
+        loc !== null &&
+        /stryker\s+disable/i.test(comment.value)
+      ) {
+        context.report({
+          loc,
+          message:
+            "Mutation-exemption comments are banned: kill the mutant with a test or fix the design, never exempt it.",
+        });
+      }
+    }
+    return {};
+  },
+};
 
 export default exadevConfig(
   {},
@@ -32,6 +57,12 @@ export default exadevConfig(
       ],
     },
   },
+  {
+    plugins: {
+      local: { rules: { "no-stryker-disable": noStrykerDisable } },
+    },
+    rules: { "local/no-stryker-disable": "error" },
+  },
   /* Test fixtures legitimately encode raw protocol values (16-byte tokens,
      24-hex hop ids, chain lengths); naming them would obscure the fixture. */
   {

package.json

@@ -56,8 +56,9 @@
     "test": "vitest run",
     "test:watch": "vitest",
     "test:mutation": "stryker run",
-    "prepublishOnly": "pnpm lint && pnpm typecheck && pnpm test && pnpm build && publint && attw --pack",
-    "prepare": "husky"
+    "prepublishOnly": "pnpm lint && pnpm typecheck && pnpm test:coverage && pnpm build && publint && attw --pack",
+    "prepare": "husky",
+    "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
     "zod": "4.5.4"
@@ -90,6 +91,7 @@
     "@stryker-mutator/core": "10.0.0",
     "@stryker-mutator/vitest-runner": "10.0.0",
     "@types/node": "26.4.1",
+    "@vitest/coverage-v8": "5.0.0",
     "commitlint": "21.2.2",
     "eslint": "10.10.0",
     "eslint-config-prettier": "10.1.8",

stryker.config.ts

@@ -4,6 +4,13 @@ const options = {
   coverageAnalysis: "perTest",
   mutate: ["src/domain/**/*.ts", "src/schemas/**/*.ts", "!src/**/*.test.ts"],
   tempDirName: ".stryker-tmp",
+  // 100% across the board: a surviving mutant is a behaviour the test suite does not pin. Mutation-exemption comments are banned by the lint rule in eslint.config.ts: a mutant that genuinely cannot be killed is a design smell to fix, not to exempt.
+  thresholds: {
+    high: 100,
+    low: 100,
+    break: 100,
+  },
+  ignorePatterns: ["dist", "dist-sea", "coverage", ".turbo"],
 };
 
 export default options;