diff --git a/packages/acp-core/src/session-interaction-mode.test.ts b/packages/acp-core/src/session-interaction-mode.test.ts
index 0bf5784286b9..b20ecd433f2d 100644
--- a/packages/acp-core/src/session-interaction-mode.test.ts
+++ b/packages/acp-core/src/session-interaction-mode.test.ts
@@ -99,8 +99,4 @@ describe("isRequesterParentOfBackgroundAcpSession", () => {
       ),
     ).toBe(true);
   });
-
-  it("delegates to isParentOwnedBackgroundAcpSession for target-only checks", () => {
-    expect(isParentOwnedBackgroundAcpSession(backgroundEntry)).toBe(true);
-  });
 });
diff --git a/src/gateway/http-common.fuzz.test.ts b/src/gateway/http-common.fuzz.test.ts
index 167e0f47ab0c..79ba47b84d5b 100644
--- a/src/gateway/http-common.fuzz.test.ts
+++ b/src/gateway/http-common.fuzz.test.ts
@@ -11,11 +11,8 @@ import {
   sendJson,
   sendMethodNotAllowed,
   sendRateLimited,
-  sendUnauthorized,
   setDefaultSecurityHeaders,
-  setSseHeaders,
   watchClientDisconnect,
-  writeDone,
 } from "./http-common.js";
 import { makeMockHttpReqRes, makeMockHttpResponse } from "./test-http-response.js";
 
@@ -176,20 +173,6 @@ describe("fuzz: sendMethodNotAllowed", () => {
   });
 });
 
-describe("fuzz: sendUnauthorized", () => {
-  it("is deterministic: always 401 with the canonical error payload", () => {
-    const expected = JSON.stringify({
-      error: { message: "Unauthorized", type: "unauthorized" },
-    });
-    for (let i = 0; i < ITERATIONS; i += 1) {
-      const { res, end } = makeMockHttpResponse();
-      sendUnauthorized(res);
-      expect(res.statusCode).toBe(401);
-      expect(end).toHaveBeenCalledWith(expected);
-    }
-  });
-});
-
 describe("fuzz: sendRateLimited", () => {
   it("sets Retry-After iff retryAfterMs is truthy and > 0, with ceil-seconds value", () => {
     const rng = makeRng(0x429);
@@ -318,42 +301,6 @@ describe("fuzz: readJsonBodyOrError", () => {
   });
 });
 
-describe("fuzz: writeDone", () => {
-  it("always writes the DONE sentinel exactly once per call", () => {
-    for (let i = 0; i < ITERATIONS; i += 1) {
-      const { res } = makeMockHttpResponse();
-      const write = vi.spyOn(res, "write");
-      writeDone(res);
-      expect(write).toHaveBeenCalledTimes(1);
-      expect(write).toHaveBeenCalledWith("data: [DONE]\n\n");
-    }
-  });
-});
-
-describe("fuzz: setSseHeaders", () => {
-  it("sets SSE headers and invokes flushHeaders when present", () => {
-    const rng = makeRng(0x55e);
-    for (let i = 0; i < ITERATIONS; i += 1) {
-      const { res, setHeader } = makeMockHttpResponse();
-      const hasFlush = rng() < 0.5;
-      const flushHeaders = vi.fn();
-      if (hasFlush) {
-        (res as unknown as { flushHeaders: () => void }).flushHeaders = flushHeaders;
-      }
-      setSseHeaders(res);
-      expect(res.statusCode).toBe(200);
-      expect(setHeader).toHaveBeenCalledWith("Content-Type", "text/event-stream; charset=utf-8");
-      expect(setHeader).toHaveBeenCalledWith("Cache-Control", "no-cache");
-      expect(setHeader).toHaveBeenCalledWith("Connection", "keep-alive");
-      if (hasFlush) {
-        expect(flushHeaders).toHaveBeenCalledTimes(1);
-      } else {
-        expect(flushHeaders).not.toHaveBeenCalled();
-      }
-    }
-  });
-});
-
 describe("fuzz: watchClientDisconnect", () => {
   it("invariants hold for arbitrary socket/controller/callback combinations", () => {
     const rng = makeRng(0xc105e);
diff --git a/src/infra/boundary-file-read.test.ts b/src/infra/boundary-file-read.test.ts
index d4cd1a647980..051ed5fbac96 100644
--- a/src/infra/boundary-file-read.test.ts
+++ b/src/infra/boundary-file-read.test.ts
@@ -9,13 +9,6 @@ import * as shim from "./boundary-file-read.js";
 const tempDirs = useAutoCleanupTempDirTracker(afterEach);
 
 describe("root file open shim", () => {
-  it("re-exports the fs-safe root file helpers", () => {
-    expect(shim.canUseRootFileOpen).toBe(upstream.canUseRootFileOpen);
-    expect(shim.matchRootFileOpenFailure).toBe(upstream.matchRootFileOpenFailure);
-    expect(shim.openRootFile).toBe(upstream.openRootFile);
-    expect(shim.openRootFileSync).toBe(upstream.openRootFileSync);
-  });
-
   it("separates missing, unreadable, and boundary-violating open failures", () => {
     const messageFor = (failure: upstream.RootFileOpenFailure) =>
       shim.describeRootFileOpenFailure({