ci: Add check for formatting [BUILD-446] (#17)

Adds buildifier to make sure files are formatted
before merging to main.

Author: jungleraptor

.github/workflows/ci.yaml

@@ -0,0 +1,32 @@
+name: rules_swiftnav
+
+on:
+  pull_request: ~
+  push:
+    branches:
+      - 'main'
+
+jobs:
+
+  check-formatting:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up credentials
+        uses: aws-actions/configure-aws-credentials@v1
+        with:
+          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          aws-region: us-west-2
+
+      - name: Set up cache
+        run: |
+          npm install -g bazels3cache
+          bazels3cache --bucket=${{ secrets.BAZEL_BUCKET }}
+
+      - name: Checkout source
+        uses: actions/checkout@v2
+
+      - name: Run format
+        run: |
+          bazel run --remote_cache=http://localhost:7777 //:buildifier
+          git diff --exit-code

.gitignore

@@ -0,0 +1 @@
+/bazel-*

BUILD.bazel

@@ -0,0 +1,5 @@
+load("@com_github_bazelbuild_buildtools//buildifier:def.bzl", "buildifier")
+
+buildifier(
+    name = "buildifier",
+)

WORKSPACE

@@ -9,3 +9,63 @@
 # WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
 
 workspace(name = "rules_swiftnav")
+
+# Everything below this comment is for buildifier
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+# buildifier is written in Go and hence needs rules_go to be built.
+# See https://github.com/bazelbuild/rules_go for the up to date setup instructions.
+http_archive(
+    name = "io_bazel_rules_go",
+    sha256 = "d6b2513456fe2229811da7eb67a444be7785f5323c6708b38d851d2b51e54d83",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/rules_go/releases/download/v0.30.0/rules_go-v0.30.0.zip",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.30.0/rules_go-v0.30.0.zip",
+    ],
+)
+
+load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies")
+
+go_rules_dependencies()
+
+load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains")
+
+go_register_toolchains(version = "1.17.2")
+
+http_archive(
+    name = "bazel_gazelle",
+    sha256 = "de69a09dc70417580aabf20a28619bb3ef60d038470c7cf8442fafcf627c21cb",
+    urls = [
+        "https://mirror.bazel.build/github.com/bazelbuild/bazel-gazelle/releases/download/v0.24.0/bazel-gazelle-v0.24.0.tar.gz",
+        "https://github.com/bazelbuild/bazel-gazelle/releases/download/v0.24.0/bazel-gazelle-v0.24.0.tar.gz",
+    ],
+)
+
+load("@bazel_gazelle//:deps.bzl", "gazelle_dependencies")
+
+# If you use WORKSPACE.bazel, use the following line instead of the bare gazelle_dependencies():
+# gazelle_dependencies(go_repository_default_config = "@//:WORKSPACE.bazel")
+gazelle_dependencies()
+
+http_archive(
+    name = "com_google_protobuf",
+    sha256 = "3bd7828aa5af4b13b99c191e8b1e884ebfa9ad371b0ce264605d347f135d2568",
+    strip_prefix = "protobuf-3.19.4",
+    urls = [
+        "https://github.com/protocolbuffers/protobuf/archive/v3.19.4.tar.gz",
+    ],
+)
+
+load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
+
+protobuf_deps()
+
+http_archive(
+    name = "com_github_bazelbuild_buildtools",
+    sha256 = "ae34c344514e08c23e90da0e2d6cb700fcd28e80c02e23e4d5715dddcb42f7b3",
+    strip_prefix = "buildtools-4.2.2",
+    urls = [
+        "https://github.com/bazelbuild/buildtools/archive/refs/tags/4.2.2.tar.gz",
+    ],
+)

third_party/check.BUILD

@@ -23,7 +23,10 @@ cmake(
     lib_source = ":srcs",
     linkopts = select({
         "@bazel_tools//src/conditions:darwin": ["-lpthread"],
-        "//conditions:default": ["-lpthread", "-lrt"],
+        "//conditions:default": [
+            "-lpthread",
+            "-lrt",
+        ],
     }),
     out_static_libs = select({
         "@bazel_tools//src/conditions:windows": ["check.lib"],