chore: add tests

deno.json

···
 	},
 	"publish": {
 		"include": ["lib/", "LICENSE", "README.md", "deno.json"]
+	},
+	"imports": {
+		"@std/assert": "jsr:@std/assert@^1.0.12"
 	}
 }

deno.lock

···
+{
+  "version": "4",
+  "specifiers": {
+    "jsr:@std/assert@^1.0.12": "1.0.12",
+    "jsr:@std/internal@^1.0.6": "1.0.6"
+  },
+  "jsr": {
+    "@std/assert@1.0.12": {
+      "integrity": "08009f0926dda9cbd8bef3a35d3b6a4b964b0ab5c3e140a4e0351fbf34af5b9a",
+      "dependencies": [
+        "jsr:@std/internal"
+      ]
+    },
+    "@std/internal@1.0.6": {
+      "integrity": "9533b128f230f73bd209408bb07a4b12f8d4255ab2a4d22a1fd6d87304aca9a4"
+    }
+  },
+  "workspace": {
+    "dependencies": [
+      "jsr:@std/assert@^1.0.12"
+    ]
+  }
+}

lib/mod.test.ts

···
+import { assertEquals } from '@std/assert';
+
+import { MaybeDecompressionStream } from './mod.ts';
+
+Deno.test({
+	name: 'decompresses a gzip stream',
+	async fn() {
+		const { readable, writable } = new MaybeDecompressionStream();
+
+		{
+			const writer = writable.getWriter();
+
+			// deno-fmt-ignore
+			writer.write(
+				new Uint8Array([
+					31, 139, 8, 0, 0, 0, 0, 0, 0, 255, 242, 72, 205, 201, 201, 215, 81,
+					40, 207, 47, 202, 73, 81, 4, 0, 0, 0, 255, 255, 3, 0, 230, 198, 230, 
+					235, 13, 0, 0, 0,
+				]),
+			);
+
+			writer.close();
+		}
+
+		{
+			let buffer = new Uint8Array(0);
+			for await (const chunk of readable) {
+				const concat = new Uint8Array(buffer.length + chunk.length);
+				concat.set(buffer);
+				concat.set(chunk, buffer.length);
+				buffer = concat;
+			}
+
+			const decoded = new TextDecoder().decode(buffer);
+
+			assertEquals(decoded, 'Hello, world!');
+		}
+	},
+});
+
+Deno.test({
+	name: 'passthroughs a non-gzip stream',
+	async fn() {
+		const { readable, writable } = new MaybeDecompressionStream();
+
+		const input = new Uint8Array([1, 2, 3, 4, 5]);
+
+		{
+			const writer = writable.getWriter();
+			writer.write(input);
+			writer.close();
+		}
+
+		{
+			let buffer = new Uint8Array(0);
+			for await (const chunk of readable) {
+				const concat = new Uint8Array(buffer.length + chunk.length);
+				concat.set(buffer);
+				concat.set(chunk, buffer.length);
+				buffer = concat;
+			}
+
+			assertEquals(buffer, input);
+		}
+	},
+});