Add CI build testing JSON as a bazel dependency.

.gitignore

@@ -23,3 +23,5 @@ cmake-build-debug
 
 test/test-*
 /.vs
+
+bazel-*

.travis.yml

@@ -39,6 +39,19 @@ matrix:
         sources: ['ubuntu-toolchain-r-test']
         packages: ['g++-4.9', 'valgrind', 'ninja-build']
 
+  # Bazel
+  - os: linux
+    compiler: gcc
+    before_install:
+      - sudo apt-get install -y pkg-config zip g++ zlib1g-dev unzip python3 wget
+      - wget -q https://github.com/bazelbuild/bazel/releases/download/0.28.1/bazel-0.28.1-installer-linux-x86_64.sh
+      - chmod +x bazel-0.28.1-installer-linux-x86_64.sh
+      - ./bazel-0.28.1-installer-linux-x86_64.sh --user
+    script: cd test/bazel_dependency && $HOME/bin/bazel build --test_output=errors --verbose_failures=true --keep_going -- //...:all
+    addons:
+      apt:
+        update: true
+
   # clang sanitizer
   - os: linux
     compiler: clang

BUILD

@@ -0,0 +1,15 @@
+package(default_visibility = ["//visibility:public"])
+
+exports_files([
+    "LICENSE.MIT"
+])
+
+load(":nlohmann_json.bzl", "nlohmann_json_hdrs", "nlohmann_json_srcs")
+
+cc_library(
+    name = "nlohmann_json",
+    srcs = nlohmann_json_srcs,
+    hdrs = nlohmann_json_hdrs,
+    includes = ["include"],
+    deps = [],
+)

README.md

@@ -148,6 +148,34 @@ endif()
 
 `thirdparty/nlohmann_json` is then a complete copy of this source tree.
 
+### Bazel
+
+In order to use this project in Bazel, the simplest approach is to download the
+single header release in your `bzl` or `BUILD` file:
+
+```
+http_file(
+    name = "com_github_nlohmann_json_single_header",
+    urls = [
+        "https://github.com/nlohmann/json/releases/download/v3.4.0/json.hpp",
+    ],
+    sha256 = "63da6d1f22b2a7bb9e4ff7d6b255cf691a161ff49532dcc45d398a53e295835f",
+)
+```
+
+Then include it as a dependency:
+
+```
+cc_library(
+    name = "foo",
+    srcs = foo_srcs,
+    hdrs = foo_hdrs,
+    deps = [
+        "@com_github_nlohmann_json_single_header//file"
+    ],
+)
+```
+
 ### Package Managers
 
 :beer: If you are using OS X and [Homebrew](http://brew.sh), just type `brew tap nlohmann/json` and `brew install nlohmann-json` and you're set. If you want the bleeding edge rather than the latest release, use `brew install nlohmann-json --HEAD`.

WORKSPACE

@@ -0,0 +1 @@
+workspace(name = "com_github_nlohmann_json")

nlohmann_json.bzl

@@ -0,0 +1,39 @@
+nlohmann_json_hdrs = [
+    "include/nlohmann/adl_serializer.hpp",
+    "include/nlohmann/json_fwd.hpp",
+    "include/nlohmann/thirdparty/hedley/hedley_undef.hpp",
+    "include/nlohmann/thirdparty/hedley/hedley.hpp",
+    "include/nlohmann/json.hpp",
+    "include/nlohmann/detail/json_pointer.hpp",
+    "include/nlohmann/detail/value_t.hpp",
+    "include/nlohmann/detail/input/json_sax.hpp",
+    "include/nlohmann/detail/input/lexer.hpp",
+    "include/nlohmann/detail/input/input_adapters.hpp",
+    "include/nlohmann/detail/input/position_t.hpp",
+    "include/nlohmann/detail/input/binary_reader.hpp",
+    "include/nlohmann/detail/input/parser.hpp",
+    "include/nlohmann/detail/iterators/internal_iterator.hpp",
+    "include/nlohmann/detail/iterators/iteration_proxy.hpp",
+    "include/nlohmann/detail/iterators/json_reverse_iterator.hpp",
+    "include/nlohmann/detail/iterators/iterator_traits.hpp",
+    "include/nlohmann/detail/iterators/iter_impl.hpp",
+    "include/nlohmann/detail/iterators/primitive_iterator.hpp",
+    "include/nlohmann/detail/json_ref.hpp",
+    "include/nlohmann/detail/macro_scope.hpp",
+    "include/nlohmann/detail/macro_unscope.hpp",
+    "include/nlohmann/detail/exceptions.hpp",
+    "include/nlohmann/detail/output/output_adapters.hpp",
+    "include/nlohmann/detail/output/serializer.hpp",
+    "include/nlohmann/detail/output/binary_writer.hpp",
+    "include/nlohmann/detail/conversions/from_json.hpp",
+    "include/nlohmann/detail/conversions/to_chars.hpp",
+    "include/nlohmann/detail/conversions/to_json.hpp",
+    "include/nlohmann/detail/meta/void_t.hpp",
+    "include/nlohmann/detail/meta/cpp_future.hpp",
+    "include/nlohmann/detail/meta/detected.hpp",
+    "include/nlohmann/detail/meta/is_sax.hpp",
+    "include/nlohmann/detail/meta/type_traits.hpp",
+]
+
+nlohmann_json_srcs = [
+]

test/bazel_dependency/BUILD

@@ -0,0 +1,11 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_binary(
+    name = "nlohmann_json_test",
+    srcs = [
+        "main.cpp",
+    ],
+    deps = [
+        "@com_github_nlohmann_json//:nlohmann_json",
+    ],
+)

test/bazel_dependency/WORKSPACE

@@ -0,0 +1,18 @@
+workspace(name = "com_github_nlohmann_json_bazel_dependency")
+
+# Developers should use something like:
+
+# http_file(
+#     name = "com_github_nlohmann_json_single_header",
+#     urls = [
+#         "https://github.com/nlohmann/json/releases/download/v3.4.0/json.hpp",
+#     ],
+#     sha256 = "63da6d1f22b2a7bb9e4ff7d6b255cf691a161ff49532dcc45d398a53e295835f",
+# )
+#
+# But this tests the trunk of nlohmann_json.
+
+local_repository(
+    name = "com_github_nlohmann_json",
+    path = "../..",
+)

test/bazel_dependency/main.cpp

@@ -0,0 +1,12 @@
+/**
+ * We use quotes per the doc's recommendation:
+ * https://docs.bazel.build/versions/master/bazel-and-cpp.html#include-paths
+ */
+#include "nlohmann/json.hpp"
+
+int main(int argc, char **argv)
+{
+    nlohmann::json j;
+
+    return 0;
+}