build: upgrade judge toolchains to Python 3.14, Java 25 and Kotlin 2.4

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
       - uses: actions/setup-python@6d4fd22b20465ccc0f7354476588e8df7c9ca0e0 # v7.1.0
         with:
-          python-version: "3.12"
+          python-version: "3.14"
           cache: pip
           cache-dependency-path: backend/pyproject.toml
       - run: pip install -e 'backend[dev]'

CHANGELOG.md

@@ -7,7 +7,7 @@ All notable changes are documented here. The format follows [Keep a Changelog](h
 ### Added
 
 - First public version: about 4,100 problems (2,830 runnable against 274k hidden tests), company frequency lists for 423 companies, reference solutions with explanations.
-- Judging in Python 3.12, Java 21, C++23 (Clang 19, as LeetCode uses) and Kotlin 2.0 in a sandboxed runner with no network access.
+- Judging in Python 3.14, Java 25, C++23 (Clang 19) and Kotlin 2.4 in a sandboxed runner with no network access.
 - Problem list, company pages, workspace with Run/Submit and custom cases, submission history, progress dashboard and export.
 - One-command setup with Docker Compose; content imported from open datasets at first run, with mirror fallbacks.
 - Repo-kept content in `content/`: new problems and extra solutions, tests or corrections for existing ones, checked in CI by `make validate-content` and marked "local" in the app.

CONTRIBUTING.md

@@ -10,7 +10,7 @@ Everyone taking part is expected to follow the [Code of Conduct](CODE_OF_CONDUCT
 
 ## Getting set up
 
-You need Docker (with Compose v2), Python 3.12, Node 22 and `make`.
+You need Docker (with Compose v2), Python 3.14, Node 22 and `make`.
 
 ```bash
 git clone https://github.com/RyPope/localcode.git && cd localcode

Makefile

@@ -14,7 +14,7 @@ logs: ## Follow app and runner logs
 	docker compose logs -f
 
 setup: ## Install local dev dependencies (Python venv + web node_modules)
-	python3.12 -m venv backend/.venv
+	python3.14 -m venv backend/.venv
 	$(PY)/pip install -e 'backend[dev]'
 	npm --prefix web ci
 

README.md

@@ -9,7 +9,7 @@
 About 4,100 problems · 2,830 judged against 274k hidden tests · company frequency lists for 423 companies · Python, Java, C++ and Kotlin
 
 [![License: MIT](https://img.shields.io/badge/license-MIT-86A3FF.svg)](LICENSE)
-![Python 3.12](https://img.shields.io/badge/python-3.12-3776AB.svg)
+![Python 3.14](https://img.shields.io/badge/python-3.14-3776AB.svg)
 ![React 18](https://img.shields.io/badge/react-18-61DAFB.svg)
 ![Docker Compose](https://img.shields.io/badge/docker-compose-2496ED.svg)
 [![PRs welcome](https://img.shields.io/badge/PRs-welcome-4FC48C.svg)](CONTRIBUTING.md)
@@ -95,7 +95,7 @@ flowchart LR
     B["Browser<br/>localhost:4173"] --> A
     subgraph Docker["Docker Compose"]
         A["app<br/>FastAPI + React UI"]
-        R["runner<br/>Python 3.12 · JDK 21 · Clang 19 · Kotlin 2.0<br/>no network"]
+        R["runner<br/>Python 3.14 · JDK 25 · Clang 19 · Kotlin 2.4<br/>no network"]
         D[("localcode-data volume<br/>content.db · user.db")]
         A -- "code + test inputs<br/>(Unix socket)" --> R
         R -- "raw outputs" --> A

backend/Dockerfile

@@ -6,7 +6,7 @@ RUN npm ci --no-audit --no-fund
 COPY web/ ./
 RUN npm run build
 
-FROM python:3.12.15-slim-trixie
+FROM python:3.14.10-slim-trixie
 RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates \
  && rm -rf /var/lib/apt/lists/* \
  && groupadd --gid 1000 localcode \

backend/localcode/importer/dataset.py

@@ -100,7 +100,7 @@ def parse_cases(test_src: str, params: list[dict], ret: str = "") -> list[dict]:
     names = [p["name"] for p in params]
     try:
         fn = ast.parse(test_src).body[0]
-    except (SyntaxError, IndexError):
+    except SyntaxError, IndexError:
         return []
     cases = []
     for st in getattr(fn, "body", []):
@@ -131,7 +131,7 @@ def parse_cases(test_src: str, params: list[dict], ret: str = "") -> list[dict]:
                 expected = []
             json.dumps(expected)  # must be JSON-representable
             cases.append({"args": args, "expected": expected})
-        except (ValueError, TypeError, SyntaxError):
+        except ValueError, TypeError, SyntaxError:
             continue
     return cases
 

backend/localcode/judging/runner_client.py

@@ -73,6 +73,6 @@ def versions() -> dict[str, str] | None:
                 with _client(endpoint, 60) as client:
                     _versions = client.get("/health").json()["versions"]
                     break
-            except (httpx.HTTPError, KeyError, ValueError):
+            except httpx.HTTPError, KeyError, ValueError:
                 continue
     return _versions

backend/pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "localcode"
 version = "0.1.0"
-requires-python = ">=3.12"
+requires-python = ">=3.14"
 dependencies = ["fastapi==0.162.0", "uvicorn==0.54.0", "httpx==0.28.1", "PyYAML==6.0.3", "markdown-it-py==4.2.0"]
 
 [project.optional-dependencies]

docs/architecture.md

@@ -4,7 +4,7 @@
 
 | Service | Image | Network | Responsibility |
 |---|---|---|---|
-| `app` | `backend/Dockerfile` (Python 3.12 + built web UI) | default (for downloads); reaches the runner via `/run/localcode/runner-*.sock` | HTTP API, static UI, content import, judging, user data |
+| `app` | `backend/Dockerfile` (Python 3.14 + built web UI) | default (for downloads); reaches the runner via `/run/localcode/runner-*.sock` | HTTP API, static UI, content import, judging, user data |
 | `runner` | `runner/Dockerfile` (pinned toolchains) | none (`network_mode: none`); serves on a Unix socket in the `runner-socket` volume | Compile and execute submissions; return raw per-case results |
 
 Data lives in the `localcode-data` volume mounted at `/data`:

ruff.toml

@@ -1,5 +1,5 @@
 line-length = 120
-target-version = "py312"
+target-version = "py314"
 extend-exclude = ["web", "**/.venv"]
 
 [lint]

runner/Dockerfile

@@ -1,16 +1,16 @@
 # Pinned toolchains: every localcode user judges against exactly these versions.
-FROM python:3.12.15-slim-trixie AS runtime
+FROM python:3.14.10-slim-trixie AS runtime
 
 RUN apt-get update \
  && apt-get install -y --no-install-recommends clang g++ nlohmann-json3-dev curl unzip ca-certificates \
  && rm -rf /var/lib/apt/lists/*
 
-COPY --from=eclipse-temurin:21.0.5_11-jdk /opt/java/openjdk /opt/java
+COPY --from=eclipse-temurin:25.0.5_8-jdk /opt/java/openjdk /opt/java
 
 # Downloads are verified against pinned SHA-256 checksums (Kotlin's matches JetBrains' published
 # .sha256; Gson's was computed from the jar matching Maven Central's published SHA-1).
-ARG KOTLIN_VERSION=2.0.21
-ARG KOTLIN_SHA256=0352c0a45bd22f80f6b26e485cd04da8047baa5de54865281fb9f89a4a7bcf2a
+ARG KOTLIN_VERSION=2.4.21
+ARG KOTLIN_SHA256=7cc140e76daf416a0424a5557f99afd7ca89ebd463ea1101261e3e01c33e75cd
 RUN curl -fsSL -o /tmp/k.zip https://github.com/JetBrains/kotlin/releases/download/v${KOTLIN_VERSION}/kotlin-compiler-${KOTLIN_VERSION}.zip \
  && echo "${KOTLIN_SHA256}  /tmp/k.zip" | sha256sum -c - \
  && unzip -q /tmp/k.zip -d /opt && rm /tmp/k.zip
@@ -44,7 +44,7 @@ CMD ["python", "-u", "server.py"]
 
 # Test image: the runtime plus pytest and the test suite (never shipped).
 FROM runtime AS test
-RUN pip install --no-cache-dir pytest==8.3.4
+RUN pip install --no-cache-dir pytest==9.2.0
 COPY pytest.ini ./
 COPY tests/ tests/
 CMD ["pytest", "-q", "tests/"]

runner/server.py

@@ -29,7 +29,7 @@ def first(cmd):
             try:
                 p = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
                 return (p.stdout or p.stderr).strip().splitlines()[0]
-            except (OSError, subprocess.TimeoutExpired, IndexError):
+            except OSError, subprocess.TimeoutExpired, IndexError:
                 return "unavailable"
 
         _versions = {