Add a trailing newline to OpenAPI spec output (#988)

Co-authored-by: Rain <rain@oxide.computer>

dropshot/src/api_description.rs

@@ -21,6 +21,7 @@ use crate::CONTENT_TYPE_URL_ENCODED;
 
 use http::Method;
 use http::StatusCode;
+use serde::de::Error;
 use serde::Deserialize;
 use serde::Serialize;
 use std::collections::BTreeMap;
@@ -1058,9 +1059,11 @@ impl<'a, Context: ServerContext> OpenApiDefinition<'a, Context> {
         out: &mut dyn std::io::Write,
     ) -> serde_json::Result<()> {
         serde_json::to_writer_pretty(
-            out,
+            &mut *out,
             &self.api.gen_openapi(self.info.clone()),
-        )
+        )?;
+        writeln!(out).map_err(serde_json::Error::custom)?;
+        Ok(())
     }
 }
 

dropshot/tests/test_openapi.json

@@ -1064,4 +1064,4 @@
       "name": "woman"
     }
   ]
-}
+}

dropshot/tests/test_openapi_fuller.json

@@ -1073,4 +1073,4 @@
       "name": "woman"
     }
   ]
-}
+}

dropshot/tests/test_pagination_schema.json

@@ -144,4 +144,4 @@
       }
     }
   }
-}
+}