Add Compression Test to ensure handling large outputs during the flush stage (#40108)
Ensure compression streams handles large flush output during the closing stages
of the compression stream.
diff --git a/compression/compression-large-flush-output.any.js b/compression/compression-large-flush-output.any.js
new file mode 100644
index 0000000..c745580
--- /dev/null
+++ b/compression/compression-large-flush-output.any.js
@@ -0,0 +1,41 @@
+// META: global=window,worker
+// META: script=third_party/pako/pako_inflate.min.js
+// META: script=resources/concatenate-stream.js
+// META: timeout=long
+
+'use strict';
+
+// This test verifies that a large flush output will not truncate the
+// final results.
+
+async function compressData(chunk, format) {
+ const cs = new CompressionStream(format);
+ const writer = cs.writable.getWriter();
+ writer.write(chunk);
+ writer.close();
+ return await concatenateStream(cs.readable);
+}
+
+// JSON-encoded array of 10 thousands numbers ("[0,1,2,...]"). This produces 48_891 bytes of data.
+const fullData = new TextEncoder().encode(JSON.stringify(Array.from({ length: 10_000 }, (_, i) => i)));
+const data = fullData.subarray(0, 35_579);
+const expectedValue = data;
+
+promise_test(async t => {
+ const compressedData = await compressData(data, 'deflate');
+ // decompress with pako, and check that we got the same result as our original string
+ assert_array_equals(expectedValue, pako.inflate(compressedData), 'value should match');
+}, `deflate compression with large flush output`);
+
+promise_test(async t => {
+ const compressedData = await compressData(data, 'gzip');
+ // decompress with pako, and check that we got the same result as our original string
+ assert_array_equals(expectedValue, pako.inflate(compressedData), 'value should match');
+}, `gzip compression with large flush output`);
+
+promise_test(async t => {
+ const compressedData = await compressData(data, 'deflate-raw');
+ // decompress with pako, and check that we got the same result as our original string
+ assert_array_equals(expectedValue, pako.inflateRaw(compressedData), 'value should match');
+}, `deflate-raw compression with large flush output`);
+
