try not treating a non-tty pipe as nonblocking

src/btjs.zig

@@ -6,18 +6,18 @@ extern const jsc_llint_end: u8;
 /// allocated using bun.default_allocator. when called from lldb, it is never freed.
 pub export fn dumpBtjsTrace() [*:0]const u8 {
     if (comptime bun.Environment.isDebug) {
-        return dumpBtjsTraceDebugImpl();
-    }
-
-    return "btjs is disabled in release builds";
-}
-
-fn dumpBtjsTraceDebugImpl() [*:0]const u8 {
-    var result_writer = std.ArrayList(u8).init(bun.default_allocator);
-    const w = result_writer.writer();
-
-    const debug_info = std.debug.getSelfDebugInfo() catch |err| {
-        w.print("Unable to dump stack trace: Unable to open debug info: {s}\x00", .{@errorName(err)}) catch {
+        var result_writer = std.ArrayList(u8).init(bun.default_allocator);
+        const w = result_writer.writer();
+        dumpBtjsTraceDebugImpl(w.any()) catch {
+            result_writer.deinit();
+            return "<oom>".ptr;
+        };
+        // remove nulls
+        for (result_writer.items) |*itm| if (itm.* == 0) {
+            itm.* = ' ';
+        };
+        // add null terminator
+        result_writer.append(0) catch {
             result_writer.deinit();
             return "<oom>".ptr;
         };
@@ -25,6 +25,17 @@ fn dumpBtjsTraceDebugImpl() [*:0]const u8 {
             result_writer.deinit();
             return "<oom>".ptr;
         }).ptr);
+    }
+
+    return "btjs is disabled in release builds";
+}
+pub fn printBtjsTrace() void {
+    dumpBtjsTraceDebugImpl(std.io.getStdOut().writer().any()) catch |err| std.log.info("Unable to dump stack trace: {s}", .{@errorName(err)});
+}
+
+fn dumpBtjsTraceDebugImpl(w: std.io.AnyWriter) !void {
+    const debug_info = std.debug.getSelfDebugInfo() catch |err| {
+        return w.print("Unable to dump stack trace: Unable to open debug info: {s}", .{@errorName(err)});
     };
 
     // std.log.info("jsc_llint_begin: {x}", .{@intFromPtr(&jsc_llint_begin)});
@@ -53,20 +64,6 @@ fn dumpBtjsTraceDebugImpl() [*:0]const u8 {
     } else {
         printLastUnwindError(&it, debug_info, w, tty_config);
     }
-
-    // remove nulls
-    for (result_writer.items) |*itm| if (itm.* == 0) {
-        itm.* = ' ';
-    };
-    // add null terminator
-    result_writer.append(0) catch {
-        result_writer.deinit();
-        return "<oom>".ptr;
-    };
-    return @ptrCast((result_writer.toOwnedSlice() catch {
-        result_writer.deinit();
-        return "<oom>".ptr;
-    }).ptr);
 }
 
 fn printSourceAtAddress(debug_info: *std.debug.SelfInfo, out_stream: anytype, address: usize, tty_config: std.io.tty.Config, fp: usize) !void {

src/bun.js/webcore/FileReader.zig

@@ -129,7 +129,7 @@ pub const Lazy = union(enum) {
                 this.file_type = .nonblocking_pipe;
             }
 
-            this.nonblocking = is_nonblocking or (this.pollable and !(file.is_atty orelse false));
+            this.nonblocking = is_nonblocking;
 
             if (this.nonblocking and this.file_type == .pipe) {
                 this.file_type = .nonblocking_pipe;

test/regression/issue/10080/10080.test.js

@@ -0,0 +1,38 @@
+import { $ } from "bun";
+import { bunExe, isWindows } from "harness";
+
+const expected_output = `got data "line 1\\n"
+✓ read at least 25ms apart
+got data "setTimeout tick"
+✓ read at least 25ms apart
+got data "line 2\\n"
+✓ read at least 25ms apart
+got data "setTimeout tick"
+✓ read at least 25ms apart
+got data "line 3\\n"
+✓ read at least 25ms apart
+got data "setTimeout tick"
+✓ read at least 25ms apart
+got data "line 4\\n"
+✓ read at least 25ms apart
+got data "setTimeout tick"
+✓ read at least 25ms apart
+got data "line 5\\n"
+✓ read at least 25ms apart
+got data "setTimeout tick"
+`;
+
+test.skipIf(isWindows)("stdin data should be emitted as stdin is read", async () => {
+  const result = Bun.spawnSync({
+    cmd: ["sh", "-c", `${bunExe()} ${import.meta.dirname}/writer | ${bunExe()} ${import.meta.dirname}/reader`],
+    stdio: ["pipe", "pipe", "pipe"],
+  });
+  expect(result.exitCode).toBe(0);
+  expect(result.stdout.toString("utf-8")).toBe(expected_output);
+  expect(result.stderr.toString("utf-8")).toMatchInlineSnapshot(`""`);
+});
+
+test("[bun shell] stdin data should be emitted as stdin is read", async () => {
+  const txt = await $`${bunExe()} ${import.meta.dirname}/writer | ${bunExe()} ${import.meta.dirname}/reader`.text();
+  expect(txt).toBe(expected_output);
+});

test/regression/issue/10080/reader.js

@@ -0,0 +1,15 @@
+let last_data = 0;
+function onData(data) {
+  const this_data = Date.now();
+  if (last_data && this_data - last_data >= 25) {
+    console.log("✓ read at least 25ms apart");
+  }
+  last_data = this_data;
+  console.log("got data", JSON.stringify(data));
+}
+
+process.stdin.on("data", data => {
+  onData(data);
+  setTimeout(() => onData("setTimeout tick"), 30);
+});
+process.stdin.setEncoding("utf-8");

test/regression/issue/10080/writer.js

@@ -0,0 +1,10 @@
+await Bun.sleep(200);
+console.log("line 1");
+await Bun.sleep(200);
+console.log("line 2");
+await Bun.sleep(200);
+console.log("line 3");
+await Bun.sleep(200);
+console.log("line 4");
+await Bun.sleep(200);
+console.log("line 5");