Polish bounded file read API

codex-rs/app-server-protocol/schema/typescript/v2/FsGetMetadataResponse.ts

@@ -21,7 +21,7 @@ isSymlink: boolean,
 /**
  * File size in bytes when available.
  */
-sizeBytes?: number,
+sizeBytes: number | null,
 /**
  * File creation time in Unix milliseconds when available, otherwise `0`.
  */

codex-rs/app-server-protocol/src/protocol/v2/fs.rs

@@ -12,11 +12,9 @@ pub struct FsReadFileParams {
     /// Absolute path to read.
     pub path: AbsolutePathBuf,
     /// Optional byte offset for a bounded read.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
     #[ts(optional = nullable, type = "number")]
     pub offset: Option<u64>,
     /// Optional maximum byte length for a bounded read.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
     #[ts(optional = nullable, type = "number")]
     pub length: Option<u64>,
 }
@@ -86,8 +84,7 @@ pub struct FsGetMetadataResponse {
     /// Whether the path itself is a symbolic link.
     pub is_symlink: bool,
     /// File size in bytes when available.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    #[ts(optional = nullable, type = "number")]
+    #[ts(type = "number | null")]
     pub size_bytes: Option<u64>,
     /// File creation time in Unix milliseconds when available, otherwise `0`.
     #[ts(type = "number")]

codex-rs/app-server-protocol/src/protocol/v2/tests.rs

@@ -717,6 +717,41 @@ fn fs_get_metadata_response_round_trips_minimal_fields() {
     assert_eq!(decoded, response);
 }
 
+#[test]
+fn fs_get_metadata_response_serializes_unavailable_size_as_null() {
+    let response = FsGetMetadataResponse {
+        is_directory: false,
+        is_file: true,
+        is_symlink: false,
+        size_bytes: None,
+        created_at_ms: 123,
+        modified_at_ms: 456,
+    };
+
+    let value = serde_json::to_value(&response).expect("serialize fs/getMetadata response");
+    assert_eq!(
+        value,
+        json!({
+            "isDirectory": false,
+            "isFile": true,
+            "isSymlink": false,
+            "sizeBytes": null,
+            "createdAtMs": 123,
+            "modifiedAtMs": 456,
+        })
+    );
+
+    let decoded = serde_json::from_value::<FsGetMetadataResponse>(json!({
+        "isDirectory": false,
+        "isFile": true,
+        "isSymlink": false,
+        "createdAtMs": 123,
+        "modifiedAtMs": 456,
+    }))
+    .expect("deserialize fs/getMetadata response without sizeBytes");
+    assert_eq!(decoded, response);
+}
+
 #[test]
 fn fs_read_file_response_round_trips_base64_data() {
     let response = FsReadFileResponse {
@@ -759,6 +794,31 @@ fn fs_read_file_params_round_trip() {
     assert_eq!(decoded, params);
 }
 
+#[test]
+fn fs_read_file_params_serializes_unbounded_read_with_null_range() {
+    let params = FsReadFileParams {
+        path: absolute_path("tmp/example.txt"),
+        offset: None,
+        length: None,
+    };
+
+    let value = serde_json::to_value(&params).expect("serialize fs/readFile params");
+    assert_eq!(
+        value,
+        json!({
+            "path": absolute_path_string("tmp/example.txt"),
+            "offset": null,
+            "length": null,
+        })
+    );
+
+    let decoded = serde_json::from_value::<FsReadFileParams>(json!({
+        "path": absolute_path_string("tmp/example.txt"),
+    }))
+    .expect("deserialize fs/readFile params without range");
+    assert_eq!(decoded, params);
+}
+
 #[test]
 fn fs_create_directory_params_round_trip_with_default_recursive() {
     let params = FsCreateDirectoryParams {