Replace arc with bazel and kokoro build runner for continuous integration

.gitignore

@@ -1,3 +1,6 @@
+bazel-*
+.kokoro-ios-runner
+
 # Jazzy
 docs/
 

.kokoro

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+# Fail on any error.
+set -e
+
+# Display commands to stderr.
+set -x
+
+if [ ! -d .kokoro-ios-runner ]; then
+  git clone https://github.com/material-foundation/kokoro-ios-runner.git .kokoro-ios-runner
+fi
+
+pushd .kokoro-ios-runner
+git fetch > /dev/null
+TAG=$(git tag -l "v3*" | sort | tail -n1)
+git checkout $TAG > /dev/null
+popd
+
+if [ -z "$KOKORO_BUILD_NUMBER" ]; then
+  tests_dir_prefix=""
+else
+  tests_dir_prefix="github/repo/"
+fi
+
+# Fixes a bug in bazel where objc_library targets have a _ prefix.
+find ${tests_dir_prefix}tests/unit -type f -name '*.swift' -exec sed -i '' -E "s/import Motion(.+)/import _Motion\1/" {} + || true
+stashed_dir=$(pwd)
+reset_imports() {
+  # Undoes our source changes from above.
+  find ${stashed_dir}/${tests_dir_prefix}tests/unit -type f -name '*.swift' -exec sed -i '' -E "s/import _Motion(.+)/import Motion\1/" {} + || true
+}
+trap reset_imports EXIT
+
+./.kokoro-ios-runner/bazel.sh test //:UnitTests 8.1.0
+
+echo "Success!"

.travis.yml

@@ -3,13 +3,9 @@ osx_image: xcode8.1
 sudo: false
 before_install:
   - gem install cocoapods --no-rdoc --no-ri --no-document --quiet
-  - git clone https://github.com/phacility/arcanist.git
-  - git clone https://github.com/phacility/libphutil.git
-  - git clone --recursive https://github.com/material-foundation/material-arc-tools.git
   - pod install --repo-update
 script:
   - set -o pipefail
-  - arcanist/bin/arc unit --everything --trace
   - xcodebuild build -workspace MotionTransitioning.xcworkspace -scheme TransitionsCatalog -sdk "iphonesimulator10.1" -destination "name=iPhone 6s,OS=10.1" ONLY_ACTIVE_ARCH=YES | xcpretty -c;
 after_success:
   - bash <(curl -s https://codecov.io/bash)

BUILD

@@ -0,0 +1,57 @@
+# Description:
+# Light-weight API for building UIViewController transitions.
+
+licenses(["notice"])  # Apache 2.0
+
+exports_files(["LICENSE"])
+
+load("@bazel_ios_warnings//:strict_warnings_objc_library.bzl", "strict_warnings_objc_library")
+
+strict_warnings_objc_library(
+    name = "MotionTransitioning",
+    srcs = glob([
+        "src/*.m",
+        "src/private/*.m",
+    ]),
+    hdrs = glob([
+        "src/*.h",
+        "src/private/*.h",
+    ]),
+    enable_modules = 1,
+    includes = ["src"],
+    visibility = ["//visibility:public"],
+)
+
+load("@build_bazel_rules_apple//apple:swift.bzl", "swift_library")
+
+swift_library(
+    name = "UnitTestsSwiftLib",
+    srcs = glob([
+        "tests/unit/*.swift",
+        "tests/unit/Transitions/*.swift",
+    ]),
+    deps = [":MotionTransitioning"],
+    visibility = ["//visibility:private"],
+)
+
+objc_library(
+    name = "UnitTestsLib",
+    srcs = glob([
+        "tests/unit/*.m",
+    ]),
+    deps = [":MotionTransitioning"],
+    visibility = ["//visibility:private"],
+)
+
+load("@build_bazel_rules_apple//apple:ios.bzl", "ios_unit_test")
+
+ios_unit_test(
+    name = "UnitTests",
+    deps = [
+      ":UnitTestsLib",
+      ":UnitTestsSwiftLib"
+    ],
+    minimum_os_version = "8.0",
+    timeout = "short",
+    visibility = ["//visibility:private"],
+)

WORKSPACE

@@ -0,0 +1,11 @@
+git_repository(
+    name = "build_bazel_rules_apple",
+    remote = "https://github.com/bazelbuild/rules_apple.git",
+    commit = "7ea0557",
+)
+
+git_repository(
+    name = "bazel_ios_warnings",
+    remote = "https://github.com/material-foundation/bazel_ios_warnings.git",
+    commit = "3e61cb5b60f52c8b9c77b5d62364d8b4d25e528f",
+)

tests/unit/Transitions/CompositeTransition.swift

@@ -0,0 +1,47 @@
+/*
+ Copyright 2017-present The Material Motion Authors. All Rights Reserved.
+
+ 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.
+ */
+
+import UIKit
+import MotionTransitioning
+
+final class CompositeTransition: NSObject, Transition, TransitionWithCustomDuration {
+
+  let transitions: [Transition]
+  init(transitions: [Transition]) {
+    self.transitions = transitions
+
+    super.init()
+  }
+
+  // The sole method we're expected to implement, start is invoked each time the view controller is
+  // presented or dismissed.
+  func start(with context: TransitionContext) {
+    transitions.forEach { context.compose(with: $0) }
+
+    context.transitionDidEnd()
+  }
+
+  // MARK: TransitionWithCustomDuration
+
+  func transitionDuration(with context: TransitionContext) -> TimeInterval {
+    let duration = transitions.flatMap { $0 as? TransitionWithCustomDuration }.map { $0.transitionDuration(with: context) }.max { $0 < $1 }
+    if let duration = duration {
+      return duration
+    }
+    return 0.35
+  }
+}
+