From bd4f8934e39279604e4a41b6fa3c037602dbe146 Mon Sep 17 00:00:00 2001
From: Zanie Blue <contact@zanie.dev>
Date: Thu, 6 Aug 2026 08:42:39 -0500
Subject: [PATCH] Stream workspace metadata JSON serialization

---
 .../uv-resolver/src/lock/export/metadata.rs   |  4 ++--
 crates/uv/src/commands/workspace/metadata.rs  | 11 ++++++---
 .../uv/tests/workspace/workspace_metadata.rs  | 24 +++++++++++++++++++
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/crates/uv-resolver/src/lock/export/metadata.rs b/crates/uv-resolver/src/lock/export/metadata.rs
index 78c5d5e072b..739b31ea800 100644
--- a/crates/uv-resolver/src/lock/export/metadata.rs
+++ b/crates/uv-resolver/src/lock/export/metadata.rs
@@ -1492,7 +1492,7 @@ impl Metadata {
         self
     }
 
-    pub fn to_json(&self) -> Result<String, MetadataError> {
-        Ok(serde_json::to_string_pretty(self)?)
+    pub fn write_json(&self, writer: impl std::io::Write) -> Result<(), MetadataError> {
+        Ok(serde_json::to_writer_pretty(writer, self)?)
     }
 }
diff --git a/crates/uv/src/commands/workspace/metadata.rs b/crates/uv/src/commands/workspace/metadata.rs
index 293f0bf395f..96b7d4c983c 100644
--- a/crates/uv/src/commands/workspace/metadata.rs
+++ b/crates/uv/src/commands/workspace/metadata.rs
@@ -1,4 +1,4 @@
-use std::fmt::Write;
+use std::io::{BufWriter, Write};
 use std::path::Path;
 
 use anyhow::{Context, Result};
@@ -22,7 +22,7 @@ use crate::commands::project::{
     ScriptInterpreter, UniversalState, WorkspacePython,
 };
 use crate::commands::{ExitStatus, UvError, diagnostics};
-use crate::printer::Printer;
+use crate::printer::{Printer, Stdout};
 use crate::settings::{FrozenSource, LockCheck, ResolverSettings};
 
 use super::module_owners::collect_module_owners;
@@ -272,7 +272,12 @@ fn metadata_for_target(target: InstallTarget<'_>) -> Result<Metadata> {
 }
 
 fn print_metadata(export: &Metadata, printer: Printer) -> Result<ExitStatus> {
-    writeln!(printer.stdout(), "{}", export.to_json()?)?;
+    if printer.stdout() == Stdout::Enabled {
+        let mut stdout = BufWriter::new(anstream::stdout().lock());
+        export.write_json(&mut stdout)?;
+        writeln!(stdout)?;
+        stdout.flush()?;
+    }
 
     Ok(ExitStatus::Success)
 }
diff --git a/crates/uv/tests/workspace/workspace_metadata.rs b/crates/uv/tests/workspace/workspace_metadata.rs
index 3b810c13b6f..6bdecddac21 100644
--- a/crates/uv/tests/workspace/workspace_metadata.rs
+++ b/crates/uv/tests/workspace/workspace_metadata.rs
@@ -129,6 +129,30 @@ fn workspace_metadata_simple() {
     assert!(!workspace.child(".venv").exists());
 }
 
+#[test]
+fn workspace_metadata_quiet() {
+    let context = uv_test::test_context!("3.12");
+    context.init().arg("foo").assert().success();
+
+    let workspace = context.temp_dir.child("foo");
+
+    uv_snapshot!(context.filters(), context.workspace_metadata().current_dir(&workspace).arg("--quiet"), @r"
+    exit_code: 0 (success)
+    ");
+}
+
+#[test]
+fn workspace_metadata_extra_quiet() {
+    let context = uv_test::test_context!("3.12");
+    context.init().arg("foo").assert().success();
+
+    let workspace = context.temp_dir.child("foo");
+
+    uv_snapshot!(context.filters(), context.workspace_metadata().current_dir(&workspace).arg("--quiet").arg("--quiet"), @r"
+    exit_code: 0 (success)
+    ");
+}
+
 #[test]
 fn workspace_metadata_ignores_unusable_environment() -> Result<()> {
     let context = uv_test::test_context!("3.12");