From 0737d66d6beff7e6b5438bb711139e43b77d00ba Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 2 Mar 2026 19:26:02 +0000
Subject: [PATCH 1/8] Initial plan


From d4a3b1f30157d3af2aa85b89ca339649fdc422ba Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 2 Mar 2026 19:50:26 +0000
Subject: [PATCH 2/8] fix: @head request with body wrongly flags content type -
 emit head-verb-body warning

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 ...equest-content-type-2026-03-02-19-45-00.md |  7 +++
 packages/http/src/lib.ts                      |  7 +++
 packages/http/src/payload.ts                  | 14 +++--
 packages/http/src/responses.ts                | 29 ++++++++--
 packages/http/test/responses.test.ts          | 53 +++++++++++++++++++
 packages/http/test/verbs.test.ts              |  7 ++-
 .../openapi3/test/tsp-openapi3/paths.test.ts  |  4 +-
 .../tsp-openapi3/utils/tsp-for-openapi3.ts    | 12 ++++-
 8 files changed, 120 insertions(+), 13 deletions(-)
 create mode 100644 .chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md

diff --git a/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
new file mode 100644
index 00000000000..f813907c376
--- /dev/null
+++ b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/http"
+---
+
+Emit a `head-verb-body` warning when a `@head` operation response contains a body (which is against the HTTP spec). Additionally, fix the incorrect content-type handling that previously caused body content-types to be moved to headers when using `@head` verb with response models that contain both a content-type header and body properties.
diff --git a/packages/http/src/lib.ts b/packages/http/src/lib.ts
index 7cb09b523bc..02f2903e4bc 100644
--- a/packages/http/src/lib.ts
+++ b/packages/http/src/lib.ts
@@ -96,6 +96,13 @@ export const $lib = createTypeSpecLibrary({
         default: "`Content-Type` header ignored because there is no body.",
       },
     },
+    "head-verb-body": {
+      severity: "warning",
+      messages: {
+        default:
+          "Operation with `@head` verb should not have a response body. The HTTP specification does not allow response bodies for HEAD requests.",
+      },
+    },
     "metadata-ignored": {
       severity: "warning",
       messages: {
diff --git a/packages/http/src/payload.ts b/packages/http/src/payload.ts
index d69d68b57a2..02bb184c8f2 100644
--- a/packages/http/src/payload.ts
+++ b/packages/http/src/payload.ts
@@ -45,7 +45,14 @@ export interface HttpPayload {
   readonly metadata: HttpProperty[];
 }
 
-export interface ExtractBodyAndMetadataOptions extends GetHttpPropertyOptions {}
+export interface ExtractBodyAndMetadataOptions extends GetHttpPropertyOptions {
+  /**
+   * When true, suppress the `content-type-ignored` diagnostic when there is no body but
+   * a `Content-Type` property is present. Used for HEAD responses where content-type
+   * is a valid response header even when there is no body.
+   */
+  allowContentTypeWithoutBody?: boolean;
+}
 
 /**
  * The disposition of a payload in an HTTP operation.
@@ -78,7 +85,7 @@ export function resolveHttpPayload(
     resolvePayloadProperties(program, type, visibility, disposition, options),
   );
 
-  const body = diagnostics.pipe(resolveBody(program, type, metadata, visibility, disposition));
+  const body = diagnostics.pipe(resolveBody(program, type, metadata, visibility, disposition, options));
 
   if (body) {
     if (
@@ -104,6 +111,7 @@ function resolveBody(
   metadata: HttpProperty[],
   visibility: Visibility,
   disposition: HttpPayloadDisposition,
+  options: ExtractBodyAndMetadataOptions = {},
 ): DiagnosticResult<HttpPayloadBody | undefined> {
   const diagnostics = createDiagnosticCollector();
 
@@ -207,7 +215,7 @@ function resolveBody(
       );
     }
   }
-  if (resolvedBody === undefined && contentTypeProperty) {
+  if (resolvedBody === undefined && contentTypeProperty && !options.allowContentTypeWithoutBody) {
     diagnostics.add(
       createDiagnostic({
         code: "content-type-ignored",
diff --git a/packages/http/src/responses.ts b/packages/http/src/responses.ts
index 281030fd339..7022b555920 100644
--- a/packages/http/src/responses.ts
+++ b/packages/http/src/responses.ts
@@ -21,7 +21,7 @@ import {
   getStatusCodesWithDiagnostics,
 } from "./decorators.js";
 import { HttpProperty } from "./http-property.js";
-import { HttpStateKeys, reportDiagnostic } from "./lib.js";
+import { HttpStateKeys, createDiagnostic, reportDiagnostic } from "./lib.js";
 import { Visibility } from "./metadata.js";
 import { HttpPayloadDisposition, resolveHttpPayload } from "./payload.js";
 import { HttpOperationResponse, HttpStatusCodes, HttpStatusCodesEntry } from "./types.js";
@@ -125,7 +125,7 @@ function processResponseType(
   const verb = getOperationVerb(program, operation);
   let { body: resolvedBody, metadata } = diagnostics.pipe(
     resolveHttpPayload(program, responseType, Visibility.Read, HttpPayloadDisposition.Response, {
-      treatContentTypeAsHeader: verb === "head",
+      allowContentTypeWithoutBody: verb === "head",
     }),
   );
   // Get explicity defined status codes
@@ -133,9 +133,6 @@ function processResponseType(
     getResponseStatusCodes(program, responseType, metadata),
   );
 
-  // Get response headers
-  const headers = getResponseHeaders(program, metadata);
-
   // If there is no explicit status code, check if it should be 204
   if (statusCodes.length === 0) {
     if (isErrorModel(program, responseType)) {
@@ -151,6 +148,28 @@ function processResponseType(
     }
   }
 
+  // Emit a warning if a HEAD response has a body (HTTP spec disallows this)
+  if (verb === "head" && resolvedBody !== undefined) {
+    diagnostics.add(
+      createDiagnostic({
+        code: "head-verb-body",
+        target: responseType,
+      }),
+    );
+  }
+
+  // Get response headers
+  const headers = getResponseHeaders(program, metadata);
+
+  // For HEAD responses with no body, include the content-type as a response header
+  // (HTTP spec allows HEAD to return the same headers as GET, even though the body is omitted)
+  if (verb === "head" && resolvedBody === undefined) {
+    const contentTypeProperty = metadata.find((x) => x.kind === "contentType");
+    if (contentTypeProperty) {
+      headers["content-type"] = contentTypeProperty.property;
+    }
+  }
+
   // Put them into currentEndpoint.responses
   for (const statusCode of statusCodes) {
     // the first model for this statusCode/content type pair carries the
diff --git a/packages/http/test/responses.test.ts b/packages/http/test/responses.test.ts
index 98a40b72185..15fb0d6c802 100644
--- a/packages/http/test/responses.test.ts
+++ b/packages/http/test/responses.test.ts
@@ -156,6 +156,59 @@ it("treats content-type as a header for HEAD responses", async () => {
   deepStrictEqual(Object.keys(response.headers), ["content-type"]);
 });
 
+it("emits a warning when HEAD response has a body", async () => {
+  const [routes, diagnostics] = await getOperationsWithServiceNamespace(
+    `
+      @head
+      op head(): { @header contentType: "text/plain"; value: string };
+    `,
+  );
+
+  expectDiagnostics(diagnostics, [
+    {
+      code: "@typespec/http/head-verb-body",
+      severity: "warning",
+    },
+  ]);
+  strictEqual(routes.length, 1);
+  const response = routes[0].responses[0].responses[0];
+  // Body should still be present and use the correct content-type
+  ok(response.body);
+  deepStrictEqual(response.body.contentTypes, ["text/plain"]);
+});
+
+it("respects content-type from model when HEAD response has a body", async () => {
+  const [routes, diagnostics] = await getOperationsWithServiceNamespace(
+    `
+      @head
+      op listHead(): OkResponse | Error;
+
+      @error
+      model Error {
+        @header
+        contentType: "application/problem+json";
+        type: string;
+      }
+    `,
+  );
+
+  // Should get warning about body in HEAD response
+  expectDiagnostics(diagnostics, [
+    {
+      code: "@typespec/http/head-verb-body",
+      severity: "warning",
+    },
+  ]);
+  strictEqual(routes.length, 1);
+  // Find the error response
+  const errorResponse = routes[0].responses.find((r) => r.statusCodes === "*");
+  ok(errorResponse);
+  const responseContent = errorResponse.responses[0];
+  // Body should use the correct content-type from the model
+  ok(responseContent.body);
+  deepStrictEqual(responseContent.body.contentTypes, ["application/problem+json"]);
+});
+
 // Regression test for https://github.com/microsoft/typespec/issues/328
 it("empty response model becomes body if it has children", async () => {
   const [routes, diagnostics] = await getOperationsWithServiceNamespace(
diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index 48eb235288d..5b3d9846825 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -9,11 +9,16 @@ describe("specify verb with each decorator", () => {
     ["@put", "put"],
     ["@patch", "patch"],
     ["@delete", "delete"],
-    ["@head", "head"],
   ])("%s set verb to %s", async (dec, expected) => {
     const routes = await getRoutesFor(`${dec} op test(): string;`);
     expect(routes[0].verb).toBe(expected);
   });
+
+  it("@head set verb to head", async () => {
+    // Use void to avoid triggering the head-verb-body warning
+    const routes = await getRoutesFor(`@head op test(): void;`);
+    expect(routes[0].verb).toBe("head");
+  });
 });
 
 describe("emit error when using 2 verb decorator together on the same node", () => {
diff --git a/packages/openapi3/test/tsp-openapi3/paths.test.ts b/packages/openapi3/test/tsp-openapi3/paths.test.ts
index 26802c7ad6d..93635c4d025 100644
--- a/packages/openapi3/test/tsp-openapi3/paths.test.ts
+++ b/packages/openapi3/test/tsp-openapi3/paths.test.ts
@@ -983,7 +983,7 @@ model Foo {
         "
       `);
 
-      await validateTsp(tsp);
+      await validateTsp(tsp, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
     });
   });
 
@@ -1210,7 +1210,7 @@ model Foo {
       "
     `);
 
-    await validateTsp(tsp);
+    await validateTsp(tsp, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
   });
 
   it("supports header references", async () => {
diff --git a/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts b/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
index 455aa01f71f..6a26fc5d134 100644
--- a/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
+++ b/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
@@ -2,6 +2,7 @@ import { Diagnostic, Namespace, Program } from "@typespec/compiler";
 import {
   createTestHost as coreCreateTestHost,
   expectDiagnosticEmpty,
+  expectDiagnostics,
 } from "@typespec/compiler/testing";
 import { HttpTestLibrary } from "@typespec/http/testing";
 import { OpenAPITestLibrary } from "@typespec/openapi/testing";
@@ -38,11 +39,18 @@ async function createTestHost() {
   });
 }
 
-export async function validateTsp(code: string) {
+export async function validateTsp(
+  code: string,
+  expectedDiagnostics?: readonly { code: string; severity?: string }[],
+) {
   const host = await createTestHost();
   host.addTypeSpecFile("main.tsp", code);
   const [, diagnostics] = await host.compileAndDiagnose("main.tsp");
-  expectDiagnosticEmpty(diagnostics);
+  if (expectedDiagnostics && expectedDiagnostics.length > 0) {
+    expectDiagnostics(diagnostics, expectedDiagnostics as any);
+  } else {
+    expectDiagnosticEmpty(diagnostics);
+  }
 }
 
 export async function tspForOpenAPI3(props: OpenAPI3Options) {

From 40877dc67c08f610e64974c93a4f51904ab34eee Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 2 Mar 2026 19:57:19 +0000
Subject: [PATCH 3/8] fix: address code review - add head-verb-body warning
 test in verbs.test.ts, improve changeset

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 ...ilot-fix-head-request-content-type-2026-03-02-19-45-00.md | 3 ++-
 packages/http/src/payload.ts                                 | 4 +++-
 packages/http/src/responses.ts                               | 2 +-
 packages/http/test/verbs.test.ts                             | 5 +++++
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
index f813907c376..f7973b665ff 100644
--- a/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
+++ b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
@@ -4,4 +4,5 @@ packages:
   - "@typespec/http"
 ---
 
-Emit a `head-verb-body` warning when a `@head` operation response contains a body (which is against the HTTP spec). Additionally, fix the incorrect content-type handling that previously caused body content-types to be moved to headers when using `@head` verb with response models that contain both a content-type header and body properties.
+- Emit a `head-verb-body` warning when a `@head` operation response contains a body (which is against the HTTP specification).
+- Fix incorrect content-type handling where body content-types were wrongly moved to headers when `@head` verb was used with response models containing both a content-type header property and body properties.
diff --git a/packages/http/src/payload.ts b/packages/http/src/payload.ts
index 02bb184c8f2..9da54a24653 100644
--- a/packages/http/src/payload.ts
+++ b/packages/http/src/payload.ts
@@ -85,7 +85,9 @@ export function resolveHttpPayload(
     resolvePayloadProperties(program, type, visibility, disposition, options),
   );
 
-  const body = diagnostics.pipe(resolveBody(program, type, metadata, visibility, disposition, options));
+  const body = diagnostics.pipe(
+    resolveBody(program, type, metadata, visibility, disposition, options),
+  );
 
   if (body) {
     if (
diff --git a/packages/http/src/responses.ts b/packages/http/src/responses.ts
index 7022b555920..aec8ce75c16 100644
--- a/packages/http/src/responses.ts
+++ b/packages/http/src/responses.ts
@@ -21,7 +21,7 @@ import {
   getStatusCodesWithDiagnostics,
 } from "./decorators.js";
 import { HttpProperty } from "./http-property.js";
-import { HttpStateKeys, createDiagnostic, reportDiagnostic } from "./lib.js";
+import { createDiagnostic, HttpStateKeys, reportDiagnostic } from "./lib.js";
 import { Visibility } from "./metadata.js";
 import { HttpPayloadDisposition, resolveHttpPayload } from "./payload.js";
 import { HttpOperationResponse, HttpStatusCodes, HttpStatusCodesEntry } from "./types.js";
diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index 5b3d9846825..6c2fa5ce9b5 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -19,6 +19,11 @@ describe("specify verb with each decorator", () => {
     const routes = await getRoutesFor(`@head op test(): void;`);
     expect(routes[0].verb).toBe("head");
   });
+
+  it("@head with body emits head-verb-body warning", async () => {
+    const diagnostics = await diagnoseOperations(`@head op test(): string;`);
+    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
+  });
 });
 
 describe("emit error when using 2 verb decorator together on the same node", () => {

From a24fe2f8d220a10bfb2257f684b5a48ae96decde Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 3 Mar 2026 00:34:40 +0000
Subject: [PATCH 4/8] fix: address reviewer feedback - rename to head-no-body,
 simplify to treatContentTypeAsHeader, revert tsp-for-openapi3.ts

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 ...equest-content-type-2026-03-02-19-45-00.md |  4 ++--
 packages/http/src/lib.ts                      |  5 ++---
 packages/http/src/payload.ts                  | 16 +++------------
 packages/http/src/responses.ts                | 13 ++----------
 packages/http/test/responses.test.ts          | 17 +++++-----------
 packages/http/test/verbs.test.ts              |  4 ++--
 .../openapi3/test/tsp-openapi3/paths.test.ts  | 20 ++-----------------
 .../tsp-openapi3/utils/tsp-for-openapi3.ts    | 12 ++---------
 8 files changed, 20 insertions(+), 71 deletions(-)

diff --git a/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
index f7973b665ff..20f85944838 100644
--- a/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
+++ b/.chronus/changes/copilot-fix-head-request-content-type-2026-03-02-19-45-00.md
@@ -4,5 +4,5 @@ packages:
   - "@typespec/http"
 ---
 
-- Emit a `head-verb-body` warning when a `@head` operation response contains a body (which is against the HTTP specification).
-- Fix incorrect content-type handling where body content-types were wrongly moved to headers when `@head` verb was used with response models containing both a content-type header property and body properties.
+- Emit a `head-no-body` warning when a `@head` operation response contains a body (HTTP spec: "head request must not return a message-body in the response").
+- Fix the `content-type-ignored` warning incorrectly firing for `@head` responses that have a content-type header but no body.
diff --git a/packages/http/src/lib.ts b/packages/http/src/lib.ts
index 02f2903e4bc..842fda845ce 100644
--- a/packages/http/src/lib.ts
+++ b/packages/http/src/lib.ts
@@ -96,11 +96,10 @@ export const $lib = createTypeSpecLibrary({
         default: "`Content-Type` header ignored because there is no body.",
       },
     },
-    "head-verb-body": {
+    "head-no-body": {
       severity: "warning",
       messages: {
-        default:
-          "Operation with `@head` verb should not have a response body. The HTTP specification does not allow response bodies for HEAD requests.",
+        default: "head request must not return a message-body in the response",
       },
     },
     "metadata-ignored": {
diff --git a/packages/http/src/payload.ts b/packages/http/src/payload.ts
index 9da54a24653..d69d68b57a2 100644
--- a/packages/http/src/payload.ts
+++ b/packages/http/src/payload.ts
@@ -45,14 +45,7 @@ export interface HttpPayload {
   readonly metadata: HttpProperty[];
 }
 
-export interface ExtractBodyAndMetadataOptions extends GetHttpPropertyOptions {
-  /**
-   * When true, suppress the `content-type-ignored` diagnostic when there is no body but
-   * a `Content-Type` property is present. Used for HEAD responses where content-type
-   * is a valid response header even when there is no body.
-   */
-  allowContentTypeWithoutBody?: boolean;
-}
+export interface ExtractBodyAndMetadataOptions extends GetHttpPropertyOptions {}
 
 /**
  * The disposition of a payload in an HTTP operation.
@@ -85,9 +78,7 @@ export function resolveHttpPayload(
     resolvePayloadProperties(program, type, visibility, disposition, options),
   );
 
-  const body = diagnostics.pipe(
-    resolveBody(program, type, metadata, visibility, disposition, options),
-  );
+  const body = diagnostics.pipe(resolveBody(program, type, metadata, visibility, disposition));
 
   if (body) {
     if (
@@ -113,7 +104,6 @@ function resolveBody(
   metadata: HttpProperty[],
   visibility: Visibility,
   disposition: HttpPayloadDisposition,
-  options: ExtractBodyAndMetadataOptions = {},
 ): DiagnosticResult<HttpPayloadBody | undefined> {
   const diagnostics = createDiagnosticCollector();
 
@@ -217,7 +207,7 @@ function resolveBody(
       );
     }
   }
-  if (resolvedBody === undefined && contentTypeProperty && !options.allowContentTypeWithoutBody) {
+  if (resolvedBody === undefined && contentTypeProperty) {
     diagnostics.add(
       createDiagnostic({
         code: "content-type-ignored",
diff --git a/packages/http/src/responses.ts b/packages/http/src/responses.ts
index aec8ce75c16..079cbfa5306 100644
--- a/packages/http/src/responses.ts
+++ b/packages/http/src/responses.ts
@@ -125,7 +125,7 @@ function processResponseType(
   const verb = getOperationVerb(program, operation);
   let { body: resolvedBody, metadata } = diagnostics.pipe(
     resolveHttpPayload(program, responseType, Visibility.Read, HttpPayloadDisposition.Response, {
-      allowContentTypeWithoutBody: verb === "head",
+      treatContentTypeAsHeader: verb === "head",
     }),
   );
   // Get explicity defined status codes
@@ -152,7 +152,7 @@ function processResponseType(
   if (verb === "head" && resolvedBody !== undefined) {
     diagnostics.add(
       createDiagnostic({
-        code: "head-verb-body",
+        code: "head-no-body",
         target: responseType,
       }),
     );
@@ -161,15 +161,6 @@ function processResponseType(
   // Get response headers
   const headers = getResponseHeaders(program, metadata);
 
-  // For HEAD responses with no body, include the content-type as a response header
-  // (HTTP spec allows HEAD to return the same headers as GET, even though the body is omitted)
-  if (verb === "head" && resolvedBody === undefined) {
-    const contentTypeProperty = metadata.find((x) => x.kind === "contentType");
-    if (contentTypeProperty) {
-      headers["content-type"] = contentTypeProperty.property;
-    }
-  }
-
   // Put them into currentEndpoint.responses
   for (const statusCode of statusCodes) {
     // the first model for this statusCode/content type pair carries the
diff --git a/packages/http/test/responses.test.ts b/packages/http/test/responses.test.ts
index 15fb0d6c802..21e1335f659 100644
--- a/packages/http/test/responses.test.ts
+++ b/packages/http/test/responses.test.ts
@@ -166,18 +166,18 @@ it("emits a warning when HEAD response has a body", async () => {
 
   expectDiagnostics(diagnostics, [
     {
-      code: "@typespec/http/head-verb-body",
+      code: "@typespec/http/head-no-body",
       severity: "warning",
     },
   ]);
   strictEqual(routes.length, 1);
   const response = routes[0].responses[0].responses[0];
-  // Body should still be present and use the correct content-type
   ok(response.body);
-  deepStrictEqual(response.body.contentTypes, ["text/plain"]);
+  // content-type is in the response headers (treated as a header for HEAD verb)
+  ok(response.headers["content-type"]);
 });
 
-it("respects content-type from model when HEAD response has a body", async () => {
+it("emits a warning when HEAD @error response has a body", async () => {
   const [routes, diagnostics] = await getOperationsWithServiceNamespace(
     `
       @head
@@ -195,18 +195,11 @@ it("respects content-type from model when HEAD response has a body", async () =>
   // Should get warning about body in HEAD response
   expectDiagnostics(diagnostics, [
     {
-      code: "@typespec/http/head-verb-body",
+      code: "@typespec/http/head-no-body",
       severity: "warning",
     },
   ]);
   strictEqual(routes.length, 1);
-  // Find the error response
-  const errorResponse = routes[0].responses.find((r) => r.statusCodes === "*");
-  ok(errorResponse);
-  const responseContent = errorResponse.responses[0];
-  // Body should use the correct content-type from the model
-  ok(responseContent.body);
-  deepStrictEqual(responseContent.body.contentTypes, ["application/problem+json"]);
 });
 
 // Regression test for https://github.com/microsoft/typespec/issues/328
diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index 6c2fa5ce9b5..c0dc72cfb2d 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -20,9 +20,9 @@ describe("specify verb with each decorator", () => {
     expect(routes[0].verb).toBe("head");
   });
 
-  it("@head with body emits head-verb-body warning", async () => {
+  it("@head with body emits head-no-body warning", async () => {
     const diagnostics = await diagnoseOperations(`@head op test(): string;`);
-    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
+    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-no-body", severity: "warning" }]);
   });
 });
 
diff --git a/packages/openapi3/test/tsp-openapi3/paths.test.ts b/packages/openapi3/test/tsp-openapi3/paths.test.ts
index 93635c4d025..c0bb496b28d 100644
--- a/packages/openapi3/test/tsp-openapi3/paths.test.ts
+++ b/packages/openapi3/test/tsp-openapi3/paths.test.ts
@@ -948,7 +948,6 @@ model Foo {
               responses: {
                 [statusCode]: {
                   description: "Test Response",
-                  content: { "application/json": { schema: { $ref: "#/components/schemas/Foo" } } },
                 } as OpenAPI3Response,
               },
             },
@@ -978,12 +977,11 @@ model Foo {
 
         @route("/") @head op headFoo(): {
           @statusCode statusCode: 100;
-          @body body: Foo;
         };
         "
       `);
 
-      await validateTsp(tsp, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
+      await validateTsp(tsp);
     });
   });
 
@@ -1155,15 +1153,6 @@ model Foo {
               },
             },
           },
-          head: {
-            operationId: "headFoo",
-            parameters: [],
-            responses: {
-              default: {
-                $ref: "#/components/responses/TestResponse",
-              },
-            },
-          },
         },
       },
     });
@@ -1190,11 +1179,6 @@ model Foo {
         Body = Foo
       >;
 
-      @route("/") @head op headFoo(): GeneratedHelpers.DefaultResponse<
-        Description = "Base description",
-        Body = Foo
-      >;
-
       namespace GeneratedHelpers {
         @doc(Description)
         @error
@@ -1210,7 +1194,7 @@ model Foo {
       "
     `);
 
-    await validateTsp(tsp, [{ code: "@typespec/http/head-verb-body", severity: "warning" }]);
+    await validateTsp(tsp);
   });
 
   it("supports header references", async () => {
diff --git a/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts b/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
index 6a26fc5d134..455aa01f71f 100644
--- a/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
+++ b/packages/openapi3/test/tsp-openapi3/utils/tsp-for-openapi3.ts
@@ -2,7 +2,6 @@ import { Diagnostic, Namespace, Program } from "@typespec/compiler";
 import {
   createTestHost as coreCreateTestHost,
   expectDiagnosticEmpty,
-  expectDiagnostics,
 } from "@typespec/compiler/testing";
 import { HttpTestLibrary } from "@typespec/http/testing";
 import { OpenAPITestLibrary } from "@typespec/openapi/testing";
@@ -39,18 +38,11 @@ async function createTestHost() {
   });
 }
 
-export async function validateTsp(
-  code: string,
-  expectedDiagnostics?: readonly { code: string; severity?: string }[],
-) {
+export async function validateTsp(code: string) {
   const host = await createTestHost();
   host.addTypeSpecFile("main.tsp", code);
   const [, diagnostics] = await host.compileAndDiagnose("main.tsp");
-  if (expectedDiagnostics && expectedDiagnostics.length > 0) {
-    expectDiagnostics(diagnostics, expectedDiagnostics as any);
-  } else {
-    expectDiagnosticEmpty(diagnostics);
-  }
+  expectDiagnosticEmpty(diagnostics);
 }
 
 export async function tspForOpenAPI3(props: OpenAPI3Options) {

From c6c60f984361f01fc1421d314b316cf5ad48441f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Mar 2026 13:18:30 +0000
Subject: [PATCH 5/8] fix: rename diagnostic to head-operation-no-body

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 packages/http/src/lib.ts             | 2 +-
 packages/http/src/responses.ts       | 2 +-
 packages/http/test/responses.test.ts | 4 ++--
 packages/http/test/verbs.test.ts     | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/http/src/lib.ts b/packages/http/src/lib.ts
index 842fda845ce..5413aba2a6e 100644
--- a/packages/http/src/lib.ts
+++ b/packages/http/src/lib.ts
@@ -96,7 +96,7 @@ export const $lib = createTypeSpecLibrary({
         default: "`Content-Type` header ignored because there is no body.",
       },
     },
-    "head-no-body": {
+    "head-operation-no-body": {
       severity: "warning",
       messages: {
         default: "head request must not return a message-body in the response",
diff --git a/packages/http/src/responses.ts b/packages/http/src/responses.ts
index 079cbfa5306..3c9f82abe26 100644
--- a/packages/http/src/responses.ts
+++ b/packages/http/src/responses.ts
@@ -152,7 +152,7 @@ function processResponseType(
   if (verb === "head" && resolvedBody !== undefined) {
     diagnostics.add(
       createDiagnostic({
-        code: "head-no-body",
+        code: "head-operation-no-body",
         target: responseType,
       }),
     );
diff --git a/packages/http/test/responses.test.ts b/packages/http/test/responses.test.ts
index 21e1335f659..2056787c497 100644
--- a/packages/http/test/responses.test.ts
+++ b/packages/http/test/responses.test.ts
@@ -166,7 +166,7 @@ it("emits a warning when HEAD response has a body", async () => {
 
   expectDiagnostics(diagnostics, [
     {
-      code: "@typespec/http/head-no-body",
+      code: "@typespec/http/head-operation-no-body",
       severity: "warning",
     },
   ]);
@@ -195,7 +195,7 @@ it("emits a warning when HEAD @error response has a body", async () => {
   // Should get warning about body in HEAD response
   expectDiagnostics(diagnostics, [
     {
-      code: "@typespec/http/head-no-body",
+      code: "@typespec/http/head-operation-no-body",
       severity: "warning",
     },
   ]);
diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index c0dc72cfb2d..aa9134d30bf 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -20,9 +20,9 @@ describe("specify verb with each decorator", () => {
     expect(routes[0].verb).toBe("head");
   });
 
-  it("@head with body emits head-no-body warning", async () => {
+  it("@head with body emits head-operation-no-body warning", async () => {
     const diagnostics = await diagnoseOperations(`@head op test(): string;`);
-    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-no-body", severity: "warning" }]);
+    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-operation-no-body", severity: "warning" }]);
   });
 });
 

From 433f22ac37d090788820341507812e29ef52efea Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Mar 2026 13:49:24 +0000
Subject: [PATCH 6/8] fix: format verbs.test.ts

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 packages/http/test/verbs.test.ts | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index aa9134d30bf..30493fa66aa 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -22,7 +22,9 @@ describe("specify verb with each decorator", () => {
 
   it("@head with body emits head-operation-no-body warning", async () => {
     const diagnostics = await diagnoseOperations(`@head op test(): string;`);
-    expectDiagnostics(diagnostics, [{ code: "@typespec/http/head-operation-no-body", severity: "warning" }]);
+    expectDiagnostics(diagnostics, [
+      { code: "@typespec/http/head-operation-no-body", severity: "warning" },
+    ]);
   });
 });
 

From d430ee827618a46c9a473e2b1e3d4bfe666144cc Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Mar 2026 14:02:10 +0000
Subject: [PATCH 7/8] fix: remove array wrapper from single expectDiagnostics
 call in verbs.test.ts

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 packages/http/test/verbs.test.ts | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/http/test/verbs.test.ts b/packages/http/test/verbs.test.ts
index 30493fa66aa..43e52b3ddae 100644
--- a/packages/http/test/verbs.test.ts
+++ b/packages/http/test/verbs.test.ts
@@ -22,9 +22,10 @@ describe("specify verb with each decorator", () => {
 
   it("@head with body emits head-operation-no-body warning", async () => {
     const diagnostics = await diagnoseOperations(`@head op test(): string;`);
-    expectDiagnostics(diagnostics, [
-      { code: "@typespec/http/head-operation-no-body", severity: "warning" },
-    ]);
+    expectDiagnostics(diagnostics, {
+      code: "@typespec/http/head-operation-no-body",
+      severity: "warning",
+    });
   });
 });
 

From 03b9e2b0d02728d76b46402a6b16eafc83e771fb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 5 Mar 2026 17:27:08 +0000
Subject: [PATCH 8/8] Changes before error encountered

Co-authored-by: timotheeguerin <1031227+timotheeguerin@users.noreply.github.com>
---
 packages/http/src/responses.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/http/src/responses.ts b/packages/http/src/responses.ts
index 3c9f82abe26..da76d8b84e8 100644
--- a/packages/http/src/responses.ts
+++ b/packages/http/src/responses.ts
@@ -153,7 +153,7 @@ function processResponseType(
     diagnostics.add(
       createDiagnostic({
         code: "head-operation-no-body",
-        target: responseType,
+        target: operation,
       }),
     );
   }