fix the Content-Encoding header

Author: Geal

apollo-router/src/axum_factory/axum_http_server_factory.rs

@@ -478,9 +478,10 @@ async fn handle_graphql(
             let body = match opt_compressor {
                 None => body,
                 Some(compressor) => {
-                    parts
-                        .headers
-                        .insert(CONTENT_ENCODING, HeaderValue::from_static("deflate"));
+                    parts.headers.insert(
+                        CONTENT_ENCODING,
+                        HeaderValue::from_static(compressor.content_encoding()),
+                    );
                     Body::wrap_stream(compressor.process(body))
                 }
             };

apollo-router/src/axum_factory/compression/mod.rs

@@ -55,6 +55,15 @@ impl Compressor {
         None
     }
 
+    pub(crate) fn content_encoding(&self) -> &'static str {
+        match self {
+            Compressor::Deflate(_) => "deflate",
+            Compressor::Gzip(_) => "gzip",
+            Compressor::Brotli(_) => "br",
+            Compressor::Zstd(_) => "zstd",
+        }
+    }
+
     pub(crate) fn process(
         mut self,
         mut stream: hyper::Body,