add brotli and zstd to CompressionStream and DecompressionStream types (#25374)

### What does this PR do?

- removes the `Unimplemented in Bun` comment on `CompressionStream` and
`DecompressionStream`
- updates the types for `CompressionStream` and `DecompressionStream` to
add a new internal `CompressionFormat` type to the constructor, which
adds `brotli` and `zstd` to the union
- adds tests for brotli and zstd usage
- adds lib.dom.d.ts exclusions for brotli and zstd as these don't exist
in the DOM version of CompressionFormat

fixes #25367

### How did you verify your code works?

typechecks and tests

packages/bun-types/bun.d.ts

@@ -3887,6 +3887,9 @@ declare module "bun" {
     static readonly byteLength: 32;
   }
 
+  /** Extends the standard web formats with `brotli` and `zstd` support. */
+  type CompressionFormat = "gzip" | "deflate" | "deflate-raw" | "brotli" | "zstd";
+
   /** Compression options for `Bun.deflateSync` and `Bun.gzipSync` */
   interface ZlibCompressionOptions {
     /**

packages/bun-types/globals.d.ts

@@ -83,6 +83,24 @@ declare var WritableStream: Bun.__internal.UseLibDomIfAvailable<
   }
 >;
 
+interface CompressionStream extends Bun.__internal.LibEmptyOrNodeStreamWebCompressionStream {}
+declare var CompressionStream: Bun.__internal.UseLibDomIfAvailable<
+  "CompressionStream",
+  {
+    prototype: CompressionStream;
+    new (format: Bun.CompressionFormat): CompressionStream;
+  }
+>;
+
+interface DecompressionStream extends Bun.__internal.LibEmptyOrNodeStreamWebDecompressionStream {}
+declare var DecompressionStream: Bun.__internal.UseLibDomIfAvailable<
+  "DecompressionStream",
+  {
+    prototype: DecompressionStream;
+    new (format: Bun.CompressionFormat): DecompressionStream;
+  }
+>;
+
 interface Worker extends Bun.__internal.LibWorkerOrBunWorker {}
 declare var Worker: Bun.__internal.UseLibDomIfAvailable<
   "Worker",
@@ -278,30 +296,6 @@ declare var Event: {
   new (type: string, eventInitDict?: Bun.EventInit): Event;
 };
 
-/**
- * Unimplemented in Bun
- */
-interface CompressionStream extends Bun.__internal.LibEmptyOrNodeStreamWebCompressionStream {}
-/**
- * Unimplemented in Bun
- */
-declare var CompressionStream: Bun.__internal.UseLibDomIfAvailable<
-  "CompressionStream",
-  typeof import("node:stream/web").CompressionStream
->;
-
-/**
- * Unimplemented in Bun
- */
-interface DecompressionStream extends Bun.__internal.LibEmptyOrNodeStreamWebCompressionStream {}
-/**
- * Unimplemented in Bun
- */
-declare var DecompressionStream: Bun.__internal.UseLibDomIfAvailable<
-  "DecompressionStream",
-  typeof import("node:stream/web").DecompressionStream
->;
-
 interface EventTarget {
   /**
    * Adds a new handler for the `type` event. Any given `listener` is added only once per `type` and per `capture` option value.

test/integration/bun-types/bun-types.test.ts

@@ -525,6 +525,26 @@ describe("@types/bun integration test", () => {
         "line": "streams.ts:49:19",
         "message": "Property 'blob' does not exist on type 'ReadableStream<Uint8Array<ArrayBufferLike>>'.",
       },
+      {
+        code: 2345,
+        line: "streams.ts:63:66",
+        message: "Argument of type '\"brotli\"' is not assignable to parameter of type 'CompressionFormat'.",
+      },
+      {
+        code: 2345,
+        line: "streams.ts:63:113",
+        message: "Argument of type '\"brotli\"' is not assignable to parameter of type 'CompressionFormat'.",
+      },
+      {
+        code: 2345,
+        line: "streams.ts:64:66",
+        message: "Argument of type '\"zstd\"' is not assignable to parameter of type 'CompressionFormat'.",
+      },
+      {
+        code: 2345,
+        line: "streams.ts:64:111",
+        message: "Argument of type '\"zstd\"' is not assignable to parameter of type 'CompressionFormat'.",
+      },
       {
         code: 2353,
         line: "websocket.ts:25:5",

test/integration/bun-types/fixture/streams.ts

@@ -60,6 +60,8 @@ expectType(node_stream.blob()).is<Promise<Blob>>();
 Bun.file("./foo.csv").stream().pipeThrough(new TextDecoderStream()).pipeThrough(new TextEncoderStream());
 
 Bun.file("./foo.csv").stream().pipeThrough(new CompressionStream("gzip")).pipeThrough(new DecompressionStream("gzip"));
+Bun.file("./foo.csv").stream().pipeThrough(new CompressionStream("brotli")).pipeThrough(new DecompressionStream("brotli"));
+Bun.file("./foo.csv").stream().pipeThrough(new CompressionStream("zstd")).pipeThrough(new DecompressionStream("zstd"));
 
 Bun.file("./foo.csv")
   .stream()

test/js/web/streams/compression.test.ts

@@ -0,0 +1,251 @@
+import { describe, expect, test } from "bun:test";
+
+describe("CompressionStream and DecompressionStream", () => {
+  describe("brotli", () => {
+    test("compresses data with brotli", async () => {
+      const input = "Hello, Bun! This is a test string for brotli compression.";
+      const encoder = new TextEncoder();
+      const data = encoder.encode(input);
+
+      const compressionStream = new CompressionStream("brotli");
+      const writer = compressionStream.writable.getWriter();
+      writer.write(data);
+      writer.close();
+
+      const compressedChunks: Uint8Array[] = [];
+      const reader = compressionStream.readable.getReader();
+
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        compressedChunks.push(value);
+      }
+
+      expect(compressedChunks.length).toBeGreaterThan(0);
+      const totalLength = compressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      expect(totalLength).toBeGreaterThan(0);
+    });
+
+    test("decompresses brotli data", async () => {
+      const input = "Hello, Bun! This is a test string for brotli decompression.";
+      const encoder = new TextEncoder();
+      const decoder = new TextDecoder();
+      const data = encoder.encode(input);
+
+      // First compress
+      const compressionStream = new CompressionStream("brotli");
+      const writer = compressionStream.writable.getWriter();
+      writer.write(data);
+      writer.close();
+
+      const compressedChunks: Uint8Array[] = [];
+      const reader = compressionStream.readable.getReader();
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        compressedChunks.push(value);
+      }
+
+      // Concatenate compressed chunks
+      const totalLength = compressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      const compressed = new Uint8Array(totalLength);
+      let offset = 0;
+      for (const chunk of compressedChunks) {
+        compressed.set(chunk, offset);
+        offset += chunk.length;
+      }
+
+      // Then decompress
+      const decompressionStream = new DecompressionStream("brotli");
+      const decompWriter = decompressionStream.writable.getWriter();
+      decompWriter.write(compressed);
+      decompWriter.close();
+
+      const decompressedChunks: Uint8Array[] = [];
+      const decompReader = decompressionStream.readable.getReader();
+      while (true) {
+        const { done, value } = await decompReader.read();
+        if (done) break;
+        decompressedChunks.push(value);
+      }
+
+      const decompressedLength = decompressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      const decompressed = new Uint8Array(decompressedLength);
+      offset = 0;
+      for (const chunk of decompressedChunks) {
+        decompressed.set(chunk, offset);
+        offset += chunk.length;
+      }
+
+      const output = decoder.decode(decompressed);
+      expect(output).toBe(input);
+    });
+
+    test("round-trip compression with brotli", async () => {
+      const testData = [
+        "Simple string",
+        Buffer.alloc(1000, "A").toString(),
+        "Mixed 123 !@# symbols",
+        "",
+        JSON.stringify({ nested: { object: "value" } }),
+      ];
+
+      for (const input of testData) {
+        const encoder = new TextEncoder();
+        const decoder = new TextDecoder();
+        const data = encoder.encode(input);
+
+        // Compress and decompress
+        const compressed = await new Response(
+          new Blob([data]).stream().pipeThrough(new CompressionStream("brotli")),
+        ).arrayBuffer();
+
+        const decompressed = await new Response(
+          new Blob([compressed]).stream().pipeThrough(new DecompressionStream("brotli")),
+        ).arrayBuffer();
+
+        const output = decoder.decode(decompressed);
+        expect(output).toBe(input);
+      }
+    });
+  });
+
+  describe("zstd", () => {
+    test("compresses data with zstd", async () => {
+      const input = "Hello, Bun! This is a test string for zstd compression.";
+      const encoder = new TextEncoder();
+      const data = encoder.encode(input);
+
+      const compressionStream = new CompressionStream("zstd");
+      const writer = compressionStream.writable.getWriter();
+      writer.write(data);
+      writer.close();
+
+      const compressedChunks: Uint8Array[] = [];
+      const reader = compressionStream.readable.getReader();
+
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        compressedChunks.push(value);
+      }
+
+      expect(compressedChunks.length).toBeGreaterThan(0);
+      const totalLength = compressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      expect(totalLength).toBeGreaterThan(0);
+    });
+
+    test("decompresses zstd data", async () => {
+      const input = "Hello, Bun! This is a test string for zstd decompression.";
+      const encoder = new TextEncoder();
+      const decoder = new TextDecoder();
+      const data = encoder.encode(input);
+
+      // First compress
+      const compressionStream = new CompressionStream("zstd");
+      const writer = compressionStream.writable.getWriter();
+      writer.write(data);
+      writer.close();
+
+      const compressedChunks: Uint8Array[] = [];
+      const reader = compressionStream.readable.getReader();
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        compressedChunks.push(value);
+      }
+
+      // Concatenate compressed chunks
+      const totalLength = compressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      const compressed = new Uint8Array(totalLength);
+      let offset = 0;
+      for (const chunk of compressedChunks) {
+        compressed.set(chunk, offset);
+        offset += chunk.length;
+      }
+
+      // Then decompress
+      const decompressionStream = new DecompressionStream("zstd");
+      const decompWriter = decompressionStream.writable.getWriter();
+      decompWriter.write(compressed);
+      decompWriter.close();
+
+      const decompressedChunks: Uint8Array[] = [];
+      const decompReader = decompressionStream.readable.getReader();
+      while (true) {
+        const { done, value } = await decompReader.read();
+        if (done) break;
+        decompressedChunks.push(value);
+      }
+
+      const decompressedLength = decompressedChunks.reduce((acc, chunk) => acc + chunk.length, 0);
+      const decompressed = new Uint8Array(decompressedLength);
+      offset = 0;
+      for (const chunk of decompressedChunks) {
+        decompressed.set(chunk, offset);
+        offset += chunk.length;
+      }
+
+      const output = decoder.decode(decompressed);
+      expect(output).toBe(input);
+    });
+
+    test("round-trip compression with zstd", async () => {
+      const testData = [
+        "Simple string",
+        Buffer.alloc(1000, "A").toString(),
+        "Mixed 123 !@# symbols",
+        "",
+        JSON.stringify({ nested: { object: "value" } }),
+      ];
+
+      for (const input of testData) {
+        const encoder = new TextEncoder();
+        const decoder = new TextDecoder();
+        const data = encoder.encode(input);
+
+        // Compress and decompress
+        const compressed = await new Response(
+          new Blob([data]).stream().pipeThrough(new CompressionStream("zstd")),
+        ).arrayBuffer();
+
+        const decompressed = await new Response(
+          new Blob([compressed]).stream().pipeThrough(new DecompressionStream("zstd")),
+        ).arrayBuffer();
+
+        const output = decoder.decode(decompressed);
+        expect(output).toBe(input);
+      }
+    });
+  });
+
+  describe("all formats", () => {
+    test("works with all compression formats", async () => {
+      const formats: Array<"gzip" | "deflate" | "deflate-raw" | "brotli" | "zstd"> = [
+        "gzip",
+        "deflate",
+        "deflate-raw",
+        "brotli",
+        "zstd",
+      ];
+
+      const input = "Test data for all compression formats!";
+      const encoder = new TextEncoder();
+      const decoder = new TextDecoder();
+      const data = encoder.encode(input);
+
+      for (const format of formats) {
+        const compressed = await new Response(
+          new Blob([data]).stream().pipeThrough(new CompressionStream(format)),
+        ).arrayBuffer();
+
+        const decompressed = await new Response(
+          new Blob([compressed]).stream().pipeThrough(new DecompressionStream(format)),
+        ).arrayBuffer();
+
+        const output = decoder.decode(decompressed);
+        expect(output).toBe(input);
+      }
+    });
+  });
+});