perf: disable cacheImmutable by default

README.md

@@ -72,7 +72,7 @@ See [below](#other-servers) for examples of use with other servers.
 |               **[`etag`](#tag)**                |   `boolean\| "weak"\| "strong"`   |                  `undefined`                  | Enable or disable etag generation.                                                                                   |
 |       **[`lastModified`](#lastmodified)**       |             `boolean`             |                  `undefined`                  | Enable or disable `Last-Modified` header. Uses the file system's last modified value.                                |
 |       **[`cacheControl`](#cachecontrol)**       | `boolean\|number\|string\|Object` |                  `undefined`                  | Enable or disable setting `Cache-Control` response header.                                                           |
-|     **[`cacheImmutable`](#cacheimmutable)**     |             `boolean`             |                    `true`                     | Enable or disable setting `Cache-Control: public, max-age=31536000, immutable` response header for immutable assets. |
+|     **[`cacheImmutable`](#cacheimmutable)**     |             `boolean`             |                    `false`                    | Enable or disable setting `Cache-Control: public, max-age=31536000, immutable` response header for immutable assets. |
 |         **[`publicPath`](#publicpath)**         |             `string`              |                  `undefined`                  | The public path that the middleware is bound to.                                                                     |
 |              **[`stats`](#stats)**              |     `boolean\|string\|Object`     |        `stats` (from a configuration)         | Stats options object or preset name.                                                                                 |
 |   **[`serverSideRender`](#serversiderender)**   |             `boolean`             |                  `undefined`                  | Instructs the module to enable or disable the server-side rendering mode.                                            |
@@ -208,13 +208,16 @@ Enable or disable setting `Cache-Control` response header.
 ### cacheImmutable
 
 Type: `Boolean`
-Default: `true`
+Default: `false`
 
 Enable or disable setting `Cache-Control: public, max-age=31536000, immutable` response header for immutable assets (i.e. asset with a hash like `image.a4c12bde.jpg`).
+
 Immutable assets are assets that have their hash in the file name therefore they can be cached, because if you change their contents the file name will be changed.
-When omitted, immutable assets use this header by default.
-Set `cacheImmutable: false` to fall back to the `cacheControl` option even for immutable assets.
-This takes precedence over the `cacheControl` option only when the asset was defined as immutable and `cacheImmutable` is not `false`.
+
+When omitted, immutable assets fall back to the `cacheControl` option.
+
+Set `cacheImmutable: true` to opt into the immutable cache header for hashed assets.
+This takes precedence over the `cacheControl` option only when the asset was defined as immutable and `cacheImmutable` is `true`.
 
 ### publicPath
 

src/index.js

@@ -126,7 +126,7 @@ const noop = () => {};
  * @property {"weak" | "strong"=} etag options to generate etag header
  * @property {boolean=} lastModified options to generate last modified header
  * @property {(boolean | number | string | { maxAge?: number, immutable?: boolean })=} cacheControl options to generate cache headers
- * @property {boolean=} cacheImmutable enable immutable cache headers for immutable assets (defaults to true when omitted)
+ * @property {boolean=} cacheImmutable enable immutable cache headers for immutable assets (defaults to false when omitted)
  */
 
 /**

src/middleware.js

@@ -621,8 +621,7 @@ function wrapper(context) {
 
       if (!getResponseHeader(res, "Cache-Control")) {
         const { cacheControl, cacheImmutable } = context.options;
-        const useImmutableCache =
-          (cacheImmutable === undefined || cacheImmutable) && extra.immutable;
+        const useImmutableCache = cacheImmutable === true && extra.immutable;
 
         let cacheControlValue;
 

test/middleware.test.js

@@ -6262,6 +6262,7 @@ describe.each([
             name,
             framework,
             compiler,
+            { cacheImmutable: true },
           );
         });
 
@@ -6306,6 +6307,7 @@ describe.each([
             name,
             framework,
             compiler,
+            { cacheImmutable: true },
           );
         });
 
@@ -6350,7 +6352,7 @@ describe.each([
             name,
             framework,
             compiler,
-            { cacheControl: 1000000 },
+            { cacheImmutable: true, cacheControl: 1000000 },
           );
         });
 
@@ -6603,7 +6605,7 @@ describe.each([
         });
       });
 
-      describe("should use cacheControl object option with explicit immutable false", () => {
+      describe("should use cacheControl object option with explicit immutable false when cacheImmutable is not enabled", () => {
         beforeEach(async () => {
           const compiler = getCompiler({
             ...webpackConfigImmutable,
@@ -6634,7 +6636,7 @@ describe.each([
           );
         });
 
-        it('should return the "200" code for the "GET" request to the immutable asset and generate `Cache-Control` header for the immutable asset by default', async () => {
+        it('should return the "200" code for the "GET" request to the immutable asset and generate `Cache-Control` header from cacheControl without immutable', async () => {
           await req.get("/main.js");
 
           const response = await req.get(
@@ -6644,7 +6646,7 @@ describe.each([
           expect(response.statusCode).toBe(200);
           expect(response.headers["cache-control"]).toBeDefined();
           expect(response.headers["cache-control"]).toBe(
-            "public, max-age=31536000, immutable",
+            "public, max-age=3000",
           );
         });
       });

types/index.d.ts

@@ -95,7 +95,7 @@
  * @property {"weak" | "strong"=} etag options to generate etag header
  * @property {boolean=} lastModified options to generate last modified header
  * @property {(boolean | number | string | { maxAge?: number, immutable?: boolean })=} cacheControl options to generate cache headers
- * @property {boolean=} cacheImmutable enable immutable cache headers for immutable assets (defaults to true when omitted)
+ * @property {boolean=} cacheImmutable enable immutable cache headers for immutable assets (defaults to false when omitted)
  */
 /**
  * @template {IncomingMessage} [RequestInternal=IncomingMessage]
@@ -363,7 +363,7 @@ export type Options<
       )
     | undefined;
   /**
-   * enable immutable cache headers for immutable assets (defaults to true when omitted)
+   * enable immutable cache headers for immutable assets (defaults to false when omitted)
    */
   cacheImmutable?: boolean | undefined;
 };