Create helper class for body extracting This does not have actual JSON parsing, as parsing JSON in Vala is totally mess, nightmare. The only (?) seemingly-reliable library is json-glib. Documentation is unorganized mess as usual in GTK-related project, so it does not dismiss the value. Extremely imperative and quite verbose API is tolerable if it's used for rare case such as string-to-enum conversion. The problem is the library is not well integrated GLib ecosystem, despite it being under GLib project. It has GObject serialization and deserialization functionality, and they are bare minimum. No array support, top-level MUST be an object... Imperative API also is full of footgun, such as getting a data from node in mismatching type returns "NULL" or "0"... In addition to that, I see no mention of "null or field omit" in methods I checked. That may okay as a C library, but definetely does not meet a quality required to be used in high-level languages, Vala. Little bit cumbersome, but seriealize and deserialize in Zig via FFI is much much much cleaner and better. Considering how widespread JSON is, I can't recommend Vala as a sole application development language to anyone, especially the application involves networking. For GTK application development, Rust would be the best choice nowadays?

Changes

3 changed files (+90/-0)

• src/Moo/Body.test.vala (new)
  • @@ -0,0 +1,37 @@
    + // Copyright 2025 Shota FUJI + // + // Licensed under the Apache License, Version 2.0 (the "License"); + // you may not use this file except in compliance with the License. + // You may obtain a copy of the License at + // + // http://www.apache.org/licenses/LICENSE-2.0 + // + // Unless required by applicable law or agreed to in writing, software + // distributed under the License is distributed on an "AS IS" BASIS, + // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + // See the License for the specific language governing permissions and + // limitations under the License. + // + // SPDX-License-Identifier: Apache-2.0 + + using GLib; + + namespace Moo { + namespace Tests { + public void add_json_body_tests() { + Test.add_func("/libmoo/json-body/parse-single", () => { + try { + var input = "MOO/1 REQUEST foo\nContent-Type: application/json\nContent-Length: 10\n\n{\"foo\": 8}"; + + var metadata = new Metadata.from_string(input); + var headers = new Headers.from_string(input, metadata); + var body = new JsonBody.from_string(input, headers); + + assert(body.data == "{\"foo\": 8}"); + } catch (Error e) { + assert_no_error(e); + } + }); + } + } + }
• src/Moo/Body.vala (new)
  • @@ -0,0 +1,52 @@
    + // Copyright 2025 Shota FUJI + // + // Licensed under the Apache License, Version 2.0 (the "License"); + // you may not use this file except in compliance with the License. + // You may obtain a copy of the License at + // + // http://www.apache.org/licenses/LICENSE-2.0 + // + // Unless required by applicable law or agreed to in writing, software + // distributed under the License is distributed on an "AS IS" BASIS, + // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + // See the License for the specific language governing permissions and + // limitations under the License. + // + // SPDX-License-Identifier: Apache-2.0 + + namespace Moo { + public errordomain JsonBodyParseError { + NO_PARSING_CONTEXT, + CONTENT_LENGTH_MISMATCH, + CONTENT_TYPE_MISMATCH, + } + + public class JsonBody : Object { + public string data { get; construct; } + + public JsonBody.from_string(string src, Headers headers) throws JsonBodyParseError { + if (headers.last_byte_index < 0) { + throw new JsonBodyParseError.NO_PARSING_CONTEXT("Headers does not contain parsed length."); + } + + if (headers.content_length == 0) { + throw new JsonBodyParseError.CONTENT_LENGTH_MISMATCH("Content-Length is zero or missing."); + } + + if (headers.content_type == null) { + throw new JsonBodyParseError.CONTENT_TYPE_MISMATCH("Content-Type is missing."); + } + + if (headers.content_type != "application/json") { + throw new JsonBodyParseError.CONTENT_TYPE_MISMATCH("Content-Type is not application/json."); + } + + var body = src.slice(headers.last_byte_index, src.length); + if (body.length != headers.content_length) { + throw new JsonBodyParseError.CONTENT_LENGTH_MISMATCH("Body size does not match the declared one."); + } + + Object(data: body); + } + } + }
• src/Moo/Moo.test.vala
  • @@ -18,5 +18,6 @@ void main(string[] args) {
    GLib.Test.init(ref args); Moo.Tests.add_metadata_tests(); Moo.Tests.add_headers_tests(); + Moo.Tests.add_json_body_tests(); GLib.Test.run(); }