Test the default Content-Type headers of Request and Response objects
diff --git a/fetch/api/request/request-init-contenttype.any.js b/fetch/api/request/request-init-contenttype.any.js
new file mode 100644
index 0000000..d8e048c
--- /dev/null
+++ b/fetch/api/request/request-init-contenttype.any.js
@@ -0,0 +1,139 @@
+function requestFromBody(body) {
+ return new Request(
+ "https://example.com",
+ {
+ method: "POST",
+ body,
+ },
+ );
+}
+
+test(() => {
+ const request = requestFromBody(undefined);
+ assert_equals(request.headers.get("Content-Type"), null);
+}, "Default Content-Type for Request with empty body");
+
+test(() => {
+ const blob = new Blob([]);
+ const request = requestFromBody(blob);
+ assert_equals(request.headers.get("Content-Type"), null);
+}, "Default Content-Type for Request with Blob body (no type set)");
+
+test(() => {
+ const blob = new Blob([], { type: "" });
+ const request = requestFromBody(blob);
+ assert_equals(request.headers.get("Content-Type"), null);
+}, "Default Content-Type for Request with Blob body (empty type)");
+
+test(() => {
+ const blob = new Blob([], { type: "a/b; c=d" });
+ const request = requestFromBody(blob);
+ assert_equals(request.headers.get("Content-Type"), "a/b; c=d");
+}, "Default Content-Type for Request with Blob body (set type)");
+
+test(() => {
+ const buffer = new Uint8Array();
+ const request = requestFromBody(buffer);
+ assert_equals(request.headers.get("Content-Type"), null);
+}, "Default Content-Type for Request with buffer source body");
+
+promise_test(async () => {
+ const formData = new FormData();
+ formData.append("a", "b");
+ const request = requestFromBody(formData);
+ const boundary = (await request.text()).split("\r\n")[0].slice(2);
+ assert_equals(
+ request.headers.get("Content-Type"),
+ `multipart/form-data; boundary=${boundary}`,
+ );
+}, "Default Content-Type for Request with FormData body");
+
+test(() => {
+ const usp = new URLSearchParams();
+ const request = requestFromBody(usp);
+ assert_equals(
+ request.headers.get("Content-Type"),
+ "application/x-www-form-urlencoded;charset=UTF-8",
+ );
+}, "Default Content-Type for Request with URLSearchParams body");
+
+test(() => {
+ const request = requestFromBody("");
+ assert_equals(
+ request.headers.get("Content-Type"),
+ "text/plain;charset=UTF-8",
+ );
+}, "Default Content-Type for Request with string body");
+
+test(() => {
+ const stream = new ReadableStream();
+ const request = requestFromBody(stream);
+ assert_equals(request.headers.get("Content-Type"), null);
+}, "Default Content-Type for Request with ReadableStream body");
+
+// -----------------------------------------------------------------------------
+
+const OVERRIDE_MIME = "test/only; mime=type";
+
+function requestFromBodyWithOverrideMime(body) {
+ return new Request(
+ "https://example.com",
+ {
+ method: "POST",
+ body,
+ headers: { "Content-Type": OVERRIDE_MIME },
+ },
+ );
+}
+
+test(() => {
+ const request = requestFromBodyWithOverrideMime(undefined);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with empty body");
+
+test(() => {
+ const blob = new Blob([]);
+ const request = requestFromBodyWithOverrideMime(blob);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with Blob body (no type set)");
+
+test(() => {
+ const blob = new Blob([], { type: "" });
+ const request = requestFromBodyWithOverrideMime(blob);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with Blob body (empty type)");
+
+test(() => {
+ const blob = new Blob([], { type: "a/b; c=d" });
+ const request = requestFromBodyWithOverrideMime(blob);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with Blob body (set type)");
+
+test(() => {
+ const buffer = new Uint8Array();
+ const request = requestFromBodyWithOverrideMime(buffer);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with buffer source body");
+
+test(() => {
+ const formData = new FormData();
+ const request = requestFromBodyWithOverrideMime(formData);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with FormData body");
+
+test(() => {
+ const usp = new URLSearchParams();
+ const request = requestFromBodyWithOverrideMime(usp);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with URLSearchParams body");
+
+test(() => {
+ const request = requestFromBodyWithOverrideMime("");
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with string body");
+
+test(() => {
+ const stream = new ReadableStream();
+ const request = requestFromBodyWithOverrideMime(stream);
+ assert_equals(request.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Request with ReadableStream body");
diff --git a/fetch/api/response/response-init-contenttype.any.js b/fetch/api/response/response-init-contenttype.any.js
new file mode 100644
index 0000000..3a7744c
--- /dev/null
+++ b/fetch/api/response/response-init-contenttype.any.js
@@ -0,0 +1,125 @@
+test(() => {
+ const response = new Response();
+ assert_equals(response.headers.get("Content-Type"), null);
+}, "Default Content-Type for Response with empty body");
+
+test(() => {
+ const blob = new Blob([]);
+ const response = new Response(blob);
+ assert_equals(response.headers.get("Content-Type"), null);
+}, "Default Content-Type for Response with Blob body (no type set)");
+
+test(() => {
+ const blob = new Blob([], { type: "" });
+ const response = new Response(blob);
+ assert_equals(response.headers.get("Content-Type"), null);
+}, "Default Content-Type for Response with Blob body (empty type)");
+
+test(() => {
+ const blob = new Blob([], { type: "a/b; c=d" });
+ const response = new Response(blob);
+ assert_equals(response.headers.get("Content-Type"), "a/b; c=d");
+}, "Default Content-Type for Response with Blob body (set type)");
+
+test(() => {
+ const buffer = new Uint8Array();
+ const response = new Response(buffer);
+ assert_equals(response.headers.get("Content-Type"), null);
+}, "Default Content-Type for Response with buffer source body");
+
+promise_test(async () => {
+ const formData = new FormData();
+ formData.append("a", "b");
+ const response = new Response(formData);
+ const boundary = (await response.text()).split("\r\n")[0].slice(2);
+ assert_equals(
+ response.headers.get("Content-Type"),
+ `multipart/form-data; boundary=${boundary}`,
+ );
+}, "Default Content-Type for Response with FormData body");
+
+test(() => {
+ const usp = new URLSearchParams();
+ const response = new Response(usp);
+ assert_equals(
+ response.headers.get("Content-Type"),
+ "application/x-www-form-urlencoded;charset=UTF-8",
+ );
+}, "Default Content-Type for Response with URLSearchParams body");
+
+test(() => {
+ const response = new Response("");
+ assert_equals(
+ response.headers.get("Content-Type"),
+ "text/plain;charset=UTF-8",
+ );
+}, "Default Content-Type for Response with string body");
+
+test(() => {
+ const stream = new ReadableStream();
+ const response = new Response(stream);
+ assert_equals(response.headers.get("Content-Type"), null);
+}, "Default Content-Type for Response with ReadableStream body");
+
+// -----------------------------------------------------------------------------
+
+const OVERRIDE_MIME = "test/only; mime=type";
+
+function responseWithOverrideMime(body) {
+ return new Response(
+ body,
+ { headers: { "Content-Type": OVERRIDE_MIME } },
+ );
+}
+
+test(() => {
+ const response = responseWithOverrideMime(undefined);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with empty body");
+
+test(() => {
+ const blob = new Blob([]);
+ const response = responseWithOverrideMime(blob);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with Blob body (no type set)");
+
+test(() => {
+ const blob = new Blob([], { type: "" });
+ const response = responseWithOverrideMime(blob);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with Blob body (empty type)");
+
+test(() => {
+ const blob = new Blob([], { type: "a/b; c=d" });
+ const response = responseWithOverrideMime(blob);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with Blob body (set type)");
+
+test(() => {
+ const buffer = new Uint8Array();
+ const response = responseWithOverrideMime(buffer);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with buffer source body");
+
+test(() => {
+ const formData = new FormData();
+ const response = responseWithOverrideMime(formData);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with FormData body");
+
+test(() => {
+ const usp = new URLSearchParams();
+ const response = responseWithOverrideMime(usp);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with URLSearchParams body");
+
+test(() => {
+ const response = responseWithOverrideMime("");
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with string body");
+
+test(() => {
+ const stream = new ReadableStream();
+ const response = responseWithOverrideMime(stream);
+ assert_equals(response.headers.get("Content-Type"), OVERRIDE_MIME);
+}, "Can override Content-Type for Response with ReadableStream body");
