fix(lockfile): emit trailing newline (#17618)

2 files changed, 4 insertions, 2 deletions

diff --git a/cli/tests/integration/npm_tests.rs b/cli/tests/integration/npm_tests.rs
index 36559b706..107bab613 100644
--- a/cli/tests/integration/npm_tests.rs
+++ b/cli/tests/integration/npm_tests.rs
@@ -1306,7 +1306,8 @@ fn lock_file_lock_write() {
       }
     }
   }
-}"#;
+}
+"#;
   temp_dir.write("deno.lock", lock_file_content);
 
   let deno = util::deno_cmd_with_deno_dir(&deno_dir)
diff --git a/lockfile/lib.rs b/lockfile/lib.rs
index ec91def15..b8caac86c 100644
--- a/lockfile/lib.rs
+++ b/lockfile/lib.rs
@@ -187,7 +187,8 @@ impl Lockfile {
       return Ok(());
     }
 
-    let json_string = serde_json::to_string_pretty(&self.content).unwrap();
+    let mut json_string = serde_json::to_string_pretty(&self.content).unwrap();
+    json_string.push('\n'); // trailing newline in file
     let mut f = std::fs::OpenOptions::new()
       .write(true)
       .create(true)