[netlify] allow opting out of Image CDN (#120)

* chore: add image CDN tests

* feat: allow image cdn opt-out

* write docs

* add changeset

* fix: put proper jsdoc values

4 files changed, 53 insertions, 0 deletions

diff --git a/packages/integrations/netlify/test/functions/fixtures/middleware/astro.config.mjs b/packages/integrations/netlify/test/functions/fixtures/middleware/astro.config.mjs
index aefd9805c..ac8593fcc 100644
--- a/packages/integrations/netlify/test/functions/fixtures/middleware/astro.config.mjs
+++ b/packages/integrations/netlify/test/functions/fixtures/middleware/astro.config.mjs
@@ -5,6 +5,7 @@ export default defineConfig({
   output: 'server',
   adapter: netlify({
     edgeMiddleware: process.env.EDGE_MIDDLEWARE === 'true',
+    imageCDN: process.env.DISABLE_IMAGE_CDN ? false : undefined,
   }),
   site: `http://example.com`,
 });
\ No newline at end of file
diff --git a/packages/integrations/netlify/test/functions/fixtures/middleware/src/astronaut.jpg b/packages/integrations/netlify/test/functions/fixtures/middleware/src/astronaut.jpg
new file mode 100644
index 000000000..d3326bcc7
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/middleware/src/astronaut.jpg
diff --git a/packages/integrations/netlify/test/functions/fixtures/middleware/src/pages/astronaut.astro b/packages/integrations/netlify/test/functions/fixtures/middleware/src/pages/astronaut.astro
new file mode 100644
index 000000000..b3da724c3
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/fixtures/middleware/src/pages/astronaut.astro
@@ -0,0 +1,9 @@
+---
+import { Image } from 'astro:assets';
+import astronautImage from "../astronaut.jpg"
+
+export const prerender = true;
+---
+
+<Image src={astronautImage} alt="an astronaut floating in space" />
+
diff --git a/packages/integrations/netlify/test/functions/image-cdn.test.js b/packages/integrations/netlify/test/functions/image-cdn.test.js
new file mode 100644
index 000000000..21b5d195e
--- /dev/null
+++ b/packages/integrations/netlify/test/functions/image-cdn.test.js
@@ -0,0 +1,43 @@
+import { loadFixture } from '@astrojs/test-utils';
+import { expect } from 'chai';
+import { describe } from 'node:test';
+
+describe('Image CDN', () => {
+	const root = new URL('./fixtures/middleware/', import.meta.url);
+
+  describe("when running outside of netlify", () => {
+    it("does not enable Image CDN", async () => {
+      const fixture = await loadFixture({ root });
+			await fixture.build();
+
+      const astronautPage = await fixture.readFile('astronaut/index.html');
+      expect(astronautPage).contains(`src="/_astro/astronaut.`)
+    })
+  })
+
+  describe("when running inside of netlify", () => {
+    it("enables Netlify Image CDN", async () => {
+      process.env.NETLIFY = 'true'
+      const fixture = await loadFixture({ root });
+			await fixture.build();
+
+      const astronautPage = await fixture.readFile('astronaut/index.html');
+      expect(astronautPage).contains(`src="/.netlify/image`)
+
+      process.env.NETLIFY = undefined
+    })
+
+    it("respects image CDN opt-out", async () => {
+      process.env.NETLIFY = 'true'
+      process.env.DISABLE_IMAGE_CDN = 'true'
+      const fixture = await loadFixture({ root });
+			await fixture.build();
+
+      const astronautPage = await fixture.readFile('astronaut/index.html');
+      expect(astronautPage).contains(`src="/_astro/astronaut.`)
+
+      process.env.NETLIFY = undefined
+      process.env.DISABLE_IMAGE_CDN = undefined
+    })
+  })
+});