fix(http2): correct canReceiveData logic per RFC 7540 (#26491)

## Summary

- Fixed inverted logic in `canReceiveData` function in HTTP/2 stream
state handling
- Added gRPC streaming tests to verify correct behavior

## Problem

The `canReceiveData` function had completely inverted logic that
reported incorrect `remoteClose` status:

| Stream State | Before (Wrong) | After (Correct) |
|--------------|----------------|-----------------|
| OPEN | `false` (can't receive) | `true` (can receive) |
| HALF_CLOSED_LOCAL | `false` (can't receive) | `true` (can receive from
remote) |
| HALF_CLOSED_REMOTE | `true` (can receive) | `false` (remote closed) |
| CLOSED | `true` (can receive) | `false` (stream done) |

Per RFC 7540 Section 5.1:
- In `HALF_CLOSED_LOCAL` state, the local endpoint has sent END_STREAM
but can still **receive** data from the remote peer
- In `HALF_CLOSED_REMOTE` state, the remote endpoint has sent END_STREAM
so no more data will be received

## Test plan

- [x] Added gRPC streaming tests covering unary, server streaming,
client streaming, and bidirectional streaming calls
- [x] Verified HTTP/2 test suite passes (same or fewer failures than
before)
- [x] Verified gRPC test suite improves (7 failures vs 9 failures before
+ 2 errors)

Closes #20875

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/bun.js/api/bun/h2_frame_parser.zig

@@ -1129,10 +1129,16 @@ pub const H2FrameParser = struct {
             return stream;
         }
 
+        /// Returns true if the stream can still receive data from the remote peer.
+        /// Per RFC 7540 Section 5.1:
+        /// - OPEN: both endpoints can send and receive
+        /// - HALF_CLOSED_LOCAL: local sent END_STREAM, but can still receive from remote
+        /// - HALF_CLOSED_REMOTE: remote sent END_STREAM, no more data to receive
+        /// - CLOSED: stream is finished
         pub fn canReceiveData(this: *Stream) bool {
             return switch (this.state) {
-                .IDLE, .RESERVED_LOCAL, .RESERVED_REMOTE, .OPEN, .HALF_CLOSED_LOCAL => false,
-                .HALF_CLOSED_REMOTE, .CLOSED => true,
+                .IDLE, .RESERVED_LOCAL, .RESERVED_REMOTE, .OPEN, .HALF_CLOSED_LOCAL => true,
+                .HALF_CLOSED_REMOTE, .CLOSED => false,
             };
         }
 

test/regression/issue/20875.test.ts

@@ -0,0 +1,287 @@
+/**
+ * Test for GitHub Issue #20875: gRPC regression - DEADLINE_EXCEEDED errors
+ * with streaming calls when using @grpc/grpc-js
+ *
+ * This test verifies that Bun's HTTP/2 client correctly handles:
+ * 1. Server streaming gRPC calls (like BatchGetDocuments)
+ * 2. Proper handling of streams in HALF_CLOSED_LOCAL state
+ */
+
+import * as grpc from "@grpc/grpc-js";
+import * as loader from "@grpc/proto-loader";
+import { afterAll, beforeAll, describe, expect, test } from "bun:test";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+const __dirname = import.meta.dirname;
+
+const protoLoaderOptions = {
+  keepCase: true,
+  longs: String,
+  enums: String,
+  defaults: true,
+  oneofs: true,
+};
+
+function loadProtoFile(file: string) {
+  const packageDefinition = loader.loadSync(file, protoLoaderOptions);
+  return grpc.loadPackageDefinition(packageDefinition);
+}
+
+const protoFile = join(__dirname, "../../js/third_party/grpc-js/fixtures/echo_service.proto");
+const echoService = loadProtoFile(protoFile).EchoService as grpc.ServiceClientConstructor;
+const ca = readFileSync(join(__dirname, "../../js/third_party/grpc-js/fixtures/ca.pem"));
+const key = readFileSync(join(__dirname, "../../js/third_party/grpc-js/fixtures/server1.key"));
+const cert = readFileSync(join(__dirname, "../../js/third_party/grpc-js/fixtures/server1.pem"));
+
+let server: grpc.Server;
+let client: InstanceType<typeof echoService>;
+let serverPort: number;
+
+describe("gRPC streaming calls", () => {
+  beforeAll(async () => {
+    server = new grpc.Server();
+
+    // Implement both unary and streaming methods
+    server.addService(echoService.service, {
+      // Unary call - works fine in the original issue
+      echo(call: grpc.ServerUnaryCall<any, any>, callback: grpc.sendUnaryData<any>) {
+        callback(null, call.request);
+      },
+
+      // Server streaming - this is what BatchGetDocuments uses
+      echoServerStream(call: grpc.ServerWritableStream<any, any>) {
+        const request = call.request;
+        // Simulate a streaming response (like BatchGetDocuments)
+        // Send multiple messages with a small delay
+        call.write({ value: "response1", value2: 1 });
+        call.write({ value: "response2", value2: 2 });
+        call.write({ value: request.value, value2: request.value2 });
+        call.end();
+      },
+
+      // Client streaming
+      echoClientStream(call: grpc.ServerReadableStream<any, any>, callback: grpc.sendUnaryData<any>) {
+        const messages: any[] = [];
+        call.on("data", data => {
+          messages.push(data);
+        });
+        call.on("end", () => {
+          callback(null, { value: `received ${messages.length} messages`, value2: messages.length });
+        });
+      },
+
+      // Bidirectional streaming
+      echoBidiStream(call: grpc.ServerDuplexStream<any, any>) {
+        call.on("data", data => {
+          call.write(data);
+        });
+        call.on("end", () => {
+          call.end();
+        });
+      },
+    });
+
+    const serverCreds = grpc.ServerCredentials.createSsl(ca, [{ private_key: key, cert_chain: cert }], false);
+
+    await new Promise<void>((resolve, reject) => {
+      server.bindAsync("127.0.0.1:0", serverCreds, (err, port) => {
+        if (err) {
+          reject(err);
+          return;
+        }
+        serverPort = port;
+        resolve();
+      });
+    });
+
+    const clientCreds = grpc.credentials.createSsl(ca);
+    client = new echoService(`127.0.0.1:${serverPort}`, clientCreds, {
+      "grpc.ssl_target_name_override": "foo.test.google.fr",
+      "grpc.default_authority": "foo.test.google.fr",
+    });
+  });
+
+  afterAll(() => {
+    client?.close();
+    server?.forceShutdown();
+  });
+
+  test("unary call should work", async () => {
+    const result = await new Promise<any>((resolve, reject) => {
+      const deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 10);
+      client.echo({ value: "test", value2: 42 }, { deadline }, (err: Error | null, response: any) => {
+        if (err) reject(err);
+        else resolve(response);
+      });
+    });
+
+    expect(result).toEqual({ value: "test", value2: 42 });
+  });
+
+  test("server streaming call should work (like BatchGetDocuments)", async () => {
+    const messages: any[] = [];
+
+    await new Promise<void>((resolve, reject) => {
+      const deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 10);
+
+      const stream = client.echoServerStream({ value: "request", value2: 100 }, { deadline });
+
+      stream.on("data", (data: any) => {
+        messages.push(data);
+      });
+
+      stream.on("error", (err: Error) => {
+        reject(err);
+      });
+
+      stream.on("end", () => {
+        resolve();
+      });
+    });
+
+    expect(messages).toHaveLength(3);
+    expect(messages[0]).toEqual({ value: "response1", value2: 1 });
+    expect(messages[1]).toEqual({ value: "response2", value2: 2 });
+    expect(messages[2]).toEqual({ value: "request", value2: 100 });
+  });
+
+  test("client streaming call should work", async () => {
+    const result = await new Promise<any>((resolve, reject) => {
+      const deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 10);
+
+      const stream = client.echoClientStream({ deadline }, (err: Error | null, response: any) => {
+        if (err) reject(err);
+        else resolve(response);
+      });
+
+      stream.write({ value: "msg1", value2: 1 });
+      stream.write({ value: "msg2", value2: 2 });
+      stream.write({ value: "msg3", value2: 3 });
+      stream.end();
+    });
+
+    expect(result).toEqual({ value: "received 3 messages", value2: 3 });
+  });
+
+  test("bidirectional streaming call should work", async () => {
+    const receivedMessages: any[] = [];
+
+    await new Promise<void>((resolve, reject) => {
+      const deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 10);
+
+      const stream = client.echoBidiStream({ deadline });
+
+      stream.on("data", (data: any) => {
+        receivedMessages.push(data);
+      });
+
+      stream.on("error", (err: Error) => {
+        reject(err);
+      });
+
+      stream.on("end", () => {
+        resolve();
+      });
+
+      // Send some messages
+      stream.write({ value: "msg1", value2: 1 });
+      stream.write({ value: "msg2", value2: 2 });
+      stream.end();
+    });
+
+    expect(receivedMessages).toHaveLength(2);
+    expect(receivedMessages[0]).toEqual({ value: "msg1", value2: 1 });
+    expect(receivedMessages[1]).toEqual({ value: "msg2", value2: 2 });
+  });
+
+  test("multiple concurrent calls with mixed types (reproduces #20875)", async () => {
+    // This test simulates the Firestore scenario:
+    // 1. Multiple unary Commit calls
+    // 2. Followed by a server streaming BatchGetDocuments call
+    // The issue is that the streaming call fails with DEADLINE_EXCEEDED
+
+    const results: any[] = [];
+
+    // First, make a few unary calls (like Commit)
+    for (let i = 0; i < 3; i++) {
+      const result = await new Promise<any>((resolve, reject) => {
+        const deadline = new Date();
+        deadline.setSeconds(deadline.getSeconds() + 10);
+        client.echo({ value: `commit${i}`, value2: i }, { deadline }, (err: Error | null, response: any) => {
+          if (err) reject(err);
+          else resolve(response);
+        });
+      });
+      results.push(result);
+    }
+
+    expect(results).toHaveLength(3);
+
+    // Now make a server streaming call (like BatchGetDocuments)
+    const streamingResults: any[] = [];
+
+    await new Promise<void>((resolve, reject) => {
+      const deadline = new Date();
+      deadline.setSeconds(deadline.getSeconds() + 10);
+
+      const stream = client.echoServerStream({ value: "batchGet", value2: 999 }, { deadline });
+
+      stream.on("data", (data: any) => {
+        streamingResults.push(data);
+      });
+
+      stream.on("error", (err: Error) => {
+        reject(err);
+      });
+
+      stream.on("end", () => {
+        resolve();
+      });
+    });
+
+    expect(streamingResults).toHaveLength(3);
+    expect(streamingResults[2]).toEqual({ value: "batchGet", value2: 999 });
+  });
+
+  test("rapid successive streaming calls", async () => {
+    // Make many streaming calls in rapid succession
+    const promises = [];
+
+    for (let i = 0; i < 10; i++) {
+      promises.push(
+        new Promise<any[]>((resolve, reject) => {
+          const messages: any[] = [];
+          const deadline = new Date();
+          deadline.setSeconds(deadline.getSeconds() + 10);
+
+          const stream = client.echoServerStream({ value: `batch${i}`, value2: i }, { deadline });
+
+          stream.on("data", (data: any) => {
+            messages.push(data);
+          });
+
+          stream.on("error", (err: Error) => {
+            reject(err);
+          });
+
+          stream.on("end", () => {
+            resolve(messages);
+          });
+        }),
+      );
+    }
+
+    const results = await Promise.all(promises);
+
+    expect(results).toHaveLength(10);
+    for (let i = 0; i < 10; i++) {
+      expect(results[i]).toHaveLength(3);
+      expect(results[i][2]).toEqual({ value: `batch${i}`, value2: i });
+    }
+  });
+});