ci: add GitHub Actions workflow

Author: tensor5

.github/workflows/ci.yml

@@ -0,0 +1,55 @@
+name: CI
+
+on:
+  pull_request:
+
+jobs:
+  format:
+    name: Check code formatting
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+        with:
+          nix_version: 2.31.2
+      - uses: nicknovitski/nix-develop@9be7cfb4b10451d3390a75dc18ad0465bed4932a # v1
+      - run: deno fmt --check
+  lint:
+    name: Check code linting
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+        with:
+          nix_version: 2.31.2
+      - uses: nicknovitski/nix-develop@9be7cfb4b10451d3390a75dc18ad0465bed4932a # v1
+      - run: deno lint
+  nix-flake-check:
+    name: Check flake.nix
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+        with:
+          nix_version: 2.31.2
+      - run: nix flake check --all-systems
+  nix-fmt:
+    name: Check Nix files formatting
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+        with:
+          nix_version: 2.31.2
+      - run: nix fmt . -- --check
+  typecheck:
+    name: Check TypeScript
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+        with:
+          nix_version: 2.31.2
+      - uses: nicknovitski/nix-develop@9be7cfb4b10451d3390a75dc18ad0465bed4932a # v1
+      - run: deno task build
+      - run: deno check