Add bazel support to Yams (#302)

Also add a GitHub action to ensure builds are working.

Validated on all Apple platforms and Linux.

.bazelrc

@@ -0,0 +1,4 @@
+# Force the tests to not run in sandboxed mode, since it can introduce
+# errors and flakes.
+test --spawn_strategy=local
+build --macos_minimum_os=10.9

.github/workflows/bazel.yml

@@ -0,0 +1,72 @@
+name: Bazel
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'Sources/**/*.[ch]'
+      - 'Sources/**/*.swift'
+      - 'Tests/**/*.swift'
+      - 'Tests/**/*.ya?ml'
+      - '**/BUILD'
+      - 'WORKSPACE'
+  pull_request:
+    paths:
+      - 'Sources/**/*.[ch]'
+      - 'Sources/**/*.swift'
+      - 'Tests/**/*.swift'
+      - 'Tests/**/*.ya?ml'
+      - '**/BUILD'
+      - 'WORKSPACE'
+
+jobs:
+  MacOS:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: MacOS build test
+        if: always()
+        run: bazelisk test //Tests:macOSBuildTest
+        shell: bash
+      - name: WatchOS build test
+        if: always()
+        run: bazelisk test //Tests:watchOSBuildTest
+        shell: bash
+      - name: iOS build test
+        if: always()
+        run: bazelisk test //Tests:iOSBuildTest
+        shell: bash
+      - name: tvOS build test
+        if: always()
+        run: bazelisk test //Tests:tvOSBuildTest
+        shell: bash
+      - name: Yams tests
+        if: always()
+        run: bazelisk test //Tests:YamsTests
+        shell: bash
+  Linux:
+    strategy:
+      matrix:
+        tag: ['5.1', '5.2', '5.3']
+    runs-on: ubuntu-latest
+    container:
+      image: swift:${{ matrix.tag }}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
+        with:
+          go-version: '^1.13.1' # The Go version to download (if necessary) and use.
+      - name: Setup Bazel
+        if: always()
+        run: go get github.com/bazelbuild/bazelisk
+        shell: bash
+      - name: Yams tests
+        if: always()
+        run: |
+             build_workspace_directory=$(bazelisk info workspace)
+             CC=clang bazelisk test //Tests:YamsTests --action_env=PATH --test_env=BUILD_WORKSPACE_DIRECTORY=$build_workspace_directory
+        shell: bash
+      - name: Yams tests logs
+        if: always()
+        run: cat bazel-out/k8-fastbuild/testlogs/Tests/YamsTests/test.log
+        shell: bash

.gitignore

@@ -69,3 +69,6 @@ fastlane/screenshots
 # Docs
 docs
 .swiftpm
+
+# Bazel
+bazel-*

CHANGELOG.md

@@ -6,7 +6,8 @@
 
 ##### Enhancements
 
-* None.
+* Adds the ability to build Yams for Linux and MacOS via Bazel.  
+  [Maxwell Elliott](https://github.com/maxwellE)
 
 ##### Bug Fixes
 

README.md

@@ -49,6 +49,21 @@ Add `pod 'Yams'` to your `Podfile`.
 
 Add `github "jpsim/Yams"` to your `Cartfile`.
 
+### Bazel
+
+In your WORKSPACE file
+
+```WORKSPACE
+YAMS_GIT_SHA = "SOME_SHA"
+http_archive(
+    name = "com_github_jpsim_yams",
+    urls = [
+        "https://github.com/jpsim/Yams/archive/%s.zip" % YAMS_GIT_SHA,
+    ],
+    strip_prefix = "yams-%s" % YAMS_GIT_SHA,
+)
+```
+
 ## Usage
 
 Yams has three groups of conversion APIs:

Sources/CYaml/BUILD

@@ -0,0 +1,15 @@
+load(
+    "@rules_cc//cc:defs.bzl",
+    "cc_library"
+)
+
+cc_library(
+    name = "CYaml",
+    srcs = glob(["src/*.c", "src/*.h"]),
+    hdrs = ["include/yaml.h"],
+    includes = ["include"],
+    visibility = [
+        "//Sources/Yams:__pkg__",
+        "//Tests:__subpackages__",
+    ],
+)

Sources/Yams/BUILD

@@ -0,0 +1,12 @@
+load("@build_bazel_rules_swift//swift:swift.bzl", "swift_library")
+
+swift_library(
+    name = "Yams",
+    module_name = "Yams",
+    srcs = glob(["*.swift"]),
+    copts = [
+        "-DSWIFT_PACKAGE",
+    ],
+    visibility = ["//visibility:public"],
+    deps = ["//Sources/CYaml:CYaml"],
+)

Tests/BUILD

@@ -0,0 +1,66 @@
+load("@build_bazel_rules_apple//apple:macos.bzl", "macos_build_test")
+load("@build_bazel_rules_apple//apple:watchos.bzl", "watchos_build_test")
+load("@build_bazel_rules_apple//apple:tvos.bzl", "tvos_build_test")
+load("@build_bazel_rules_apple//apple:ios.bzl", "ios_build_test")
+load("@build_bazel_rules_swift//swift:swift.bzl", "swift_test")
+
+config_setting(
+    name = "linux",
+    constraint_values = ["@platforms//os:linux"],
+)
+
+genrule(
+    name = "LinuxMain",
+    srcs = ["LinuxMain.swift"],
+    outs = ["main.swift"],
+    cmd = "cp $< $@"
+)
+
+swift_test(
+    name = "YamsTests",
+    module_name = "YamsTests",
+    srcs = glob(["YamsTests/*.swift"]) + select({
+        ":linux": ["main.swift"],
+        "//conditions:default": [],
+    }),
+    data = glob(["YamsTests/Fixtures/**/*.*"]),
+    deps = [
+        "//Sources/Yams:Yams",
+    ],
+)
+
+macos_build_test(
+    name = "macOSBuildTest",
+    minimum_os_version = "10.9",
+    targets = [
+        "//Sources/Yams:Yams",
+        "//Sources/CYaml:CYaml",
+    ],
+)
+
+watchos_build_test(
+    name = "watchOSBuildTest",
+    minimum_os_version = "2.0",
+    targets = [
+        "//Sources/Yams:Yams",
+        "//Sources/CYaml:CYaml",
+    ],
+)
+
+tvos_build_test(
+    name = "tvOSBuildTest",
+    minimum_os_version = "9.0",
+    targets = [
+        "//Sources/Yams:Yams",
+        "//Sources/CYaml:CYaml",
+    ],
+)
+
+ios_build_test(
+    name = "iOSBuildTest",
+    minimum_os_version = "8.0",
+    targets = [
+        "//Sources/Yams:Yams",
+        "//Sources/CYaml:CYaml",
+    ],
+)

Tests/YamsTests/PerformanceTests.swift

@@ -10,10 +10,13 @@ import Foundation
 import XCTest
 import Yams
 
-private let fixturesDirectory = URL(fileURLWithPath: #file).deletingLastPathComponent().path + "/Fixtures/"
-
 class PerformanceTests: XCTestCase {
-    let filename = fixturesDirectory + "SourceKitten#289/debug.yaml"
+    private let fixturesDirectory: String = {
+        if let buildWorkspace = ProcessInfo.processInfo.environment["BUILD_WORKSPACE_DIRECTORY"] {
+            return "\(buildWorkspace)/Tests/YamsTests/Fixtures/"
+        }
+        return URL(fileURLWithPath: #file).deletingLastPathComponent().path + "/Fixtures/"
+    }()
     let expectedImports = ["/SourceKitten/.build/debug"]
     let expectedOtherArguments = [
         "-j8", "-D", "SWIFT_PACKAGE", "-Onone", "-g", "-enable-testing",
@@ -58,7 +61,7 @@ class PerformanceTests: XCTestCase {
     ]
 
     func loadYAML() throws -> String {
-        let data = try Data(contentsOf: URL(fileURLWithPath: filename))
+        let data = try Data(contentsOf: URL(fileURLWithPath: fixturesDirectory + "/SourceKitten#289/debug.yaml"))
         return String(data: data, encoding: .utf8)!
     }
 

WORKSPACE

@@ -0,0 +1,29 @@
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "build_bazel_rules_apple",
+    sha256 = "09423d57ace0fca1b84e19326dc9aadd42f2be52f1b5a15bc652d18c2c1dee71",
+    url = "https://github.com/bazelbuild/rules_apple/releases/download/0.30.0/rules_apple.0.30.0.tar.gz",
+)
+
+load(
+    "@build_bazel_rules_apple//apple:repositories.bzl",
+    "apple_rules_dependencies",
+)
+
+apple_rules_dependencies()
+
+load(
+    "@build_bazel_rules_swift//swift:repositories.bzl",
+    "swift_rules_dependencies",
+)
+
+swift_rules_dependencies()
+
+load(
+    "@build_bazel_rules_swift//swift:extras.bzl",
+    "swift_rules_extra_dependencies",
+)
+
+swift_rules_extra_dependencies()