Overhaul workspace file to use only a single setup function (#129)

WORKSPACE

@@ -1,44 +1,7 @@
 workspace(name = "io_bazel_skydoc")
-load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
-git_repository(
-    name = "io_bazel_rules_sass",
-    remote = "https://github.com/bazelbuild/rules_sass.git",
-    tag = "1.15.1",
-)
-git_repository(
-    name = "bazel_skylib",
-    remote = "https://github.com/bazelbuild/bazel-skylib.git",
-    tag = "0.6.0",
-)
-# Using bazel_skylib 0.6.0 requires at least version 0.16.2 of rules_nodejs.
-# (rules_sass depends on rules_nodejs, and but the current rules_sass version
-# depends on an older version of rule_nodejs.)
-# TODO: Remove this direct dependency when rules_sass can be updated.
-git_repository(
-    name = "build_bazel_rules_nodejs",
-    remote = "https://github.com/bazelbuild/rules_nodejs.git",
-    tag = "0.16.2",
-)
-git_repository(
-    name = "io_bazel",
-    remote = "https://github.com/bazelbuild/bazel.git",
-    # TODO: Update to a newer tagged version when available.
-    commit = "e7ebb7e68d35ae090d91fe6b4c92c1c831421faa",  # 2018-11-26
-)
-# Required by @io_bazel.
-# Note that @protobuf is already created in skydoc_repositories().
-# Maybe keep this in sync with that.
-git_repository(
-    name = "com_google_protobuf",
-    remote = "https://github.com/protocolbuffers/protobuf.git",
-    # Latest tagged version at time of writing is v3.6.1, which doesn't
-    # include fixes for --incompatible_package_name_is_a_function,
-    # --incompatible_new_actions_api, and possibly others.
-    # TODO: Update to a newer tagged version when available.
-    commit = "7b28271a61a3da0a37f6fda399b0c4c86464e5b3",  # 2018-11-16
-)
+load(":setup.bzl", "skydoc_repositories")
+skydoc_repositories()
 
 load("@io_bazel_rules_sass//:package.bzl", "rules_sass_dependencies")
 rules_sass_dependencies()
@@ -48,6 +11,3 @@ node_repositories()
 
 load("@io_bazel_rules_sass//:defs.bzl", "sass_repositories")
 sass_repositories()
-
-load("//skylark:skylark.bzl", "skydoc_repositories")
-skydoc_repositories()

setup.bzl

@@ -0,0 +1,141 @@
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+def _include_if_not_defined(repo_rule, name, **kwargs):
+    if name not in native.existing_rules():
+        repo_rule(name = name, **kwargs)
+
+JINJA2_BUILD_FILE = """
+py_library(
+    name = "jinja2",
+    srcs = glob(["jinja2/*.py"]),
+    srcs_version = "PY2AND3",
+    deps = [
+        "@markupsafe_archive//:markupsafe",
+    ],
+    visibility = ["//visibility:public"],
+)
+"""
+
+MARKUPSAFE_BUILD_FILE = """
+py_library(
+    name = "markupsafe",
+    srcs = glob(["markupsafe/*.py"]),
+    srcs_version = "PY2AND3",
+    visibility = ["//visibility:public"],
+)
+"""
+
+MISTUNE_BUILD_FILE = """
+py_library(
+    name = "mistune",
+    srcs = ["mistune.py"],
+    srcs_version = "PY2AND3",
+    visibility = ["//visibility:public"],
+)
+"""
+
+SIX_BUILD_FILE = """
+py_library(
+    name = "six",
+    srcs = ["six.py"],
+    srcs_version = "PY2AND3",
+    visibility = ["//visibility:public"],
+)
+"""
+
+def skydoc_repositories():
+    """Adds the external repositories used by the skylark rules."""
+    _include_if_not_defined(
+        git_repository,
+        name = "bazel_skylib",
+        remote = "https://github.com/bazelbuild/bazel-skylib.git",
+        tag = "0.6.0",
+    )
+    _include_if_not_defined(
+        git_repository,
+        name = "io_bazel_rules_sass",
+        remote = "https://github.com/bazelbuild/rules_sass.git",
+        tag = "1.15.1",
+    )
+    _include_if_not_defined(
+        git_repository,
+        name = "io_bazel_rules_sass",
+        remote = "https://github.com/bazelbuild/rules_sass.git",
+        tag = "1.15.1",
+    )
+    _include_if_not_defined(
+        git_repository,
+        name = "io_bazel",
+        remote = "https://github.com/bazelbuild/bazel.git",
+        # TODO: Update to a newer tagged version when available.
+        commit = "e7ebb7e68d35ae090d91fe6b4c92c1c831421faa",  # 2018-11-26
+    )
+    _include_if_not_defined(
+        git_repository,
+        name = "com_google_protobuf",
+        remote = "https://github.com/protocolbuffers/protobuf.git",
+        # Latest tagged version at time of writing is v3.6.1, which doesn't
+        # include fixes for --incompatible_package_name_is_a_function,
+        # --incompatible_new_actions_api, and possibly others.
+        # TODO: Update to a newer tagged version when available.
+        commit = "7b28271a61a3da0a37f6fda399b0c4c86464e5b3",  # 2018-11-16
+    )
+    _include_if_not_defined(
+        git_repository,
+        name = "io_bazel_rules_sass",
+        remote = "https://github.com/bazelbuild/rules_sass.git",
+        tag = "1.15.1",
+    )
+
+    _include_if_not_defined(
+        http_archive,
+        name = "markupsafe_archive",
+        urls = ["https://pypi.python.org/packages/source/M/MarkupSafe/MarkupSafe-0.23.tar.gz#md5=f5ab3deee4c37cd6a922fb81e730da6e"],
+        sha256 = "a4ec1aff59b95a14b45eb2e23761a0179e98319da5a7eb76b56ea8cdc7b871c3",
+        build_file_content = MARKUPSAFE_BUILD_FILE,
+        strip_prefix = "MarkupSafe-0.23",
+    )
+    native.bind(
+        name = "markupsafe",
+        actual = "@markupsafe_archive//:markupsafe",
+    )
+
+    _include_if_not_defined(
+        http_archive,
+        name = "jinja2_archive",
+        urls = ["https://pypi.python.org/packages/source/J/Jinja2/Jinja2-2.8.tar.gz#md5=edb51693fe22c53cee5403775c71a99e"],
+        sha256 = "bc1ff2ff88dbfacefde4ddde471d1417d3b304e8df103a7a9437d47269201bf4",
+        build_file_content = JINJA2_BUILD_FILE,
+        strip_prefix = "Jinja2-2.8",
+    )
+    native.bind(
+        name = "jinja2",
+        actual = "@jinja2_archive//:jinja2",
+    )
+
+    _include_if_not_defined(
+        http_archive,
+        name = "mistune_archive",
+        urls = ["https://pypi.python.org/packages/source/m/mistune/mistune-0.7.1.tar.gz#md5=057bc28bf629d6a1283d680a34ed9d0f"],
+        sha256 = "6076dedf768348927d991f4371e5a799c6a0158b16091df08ee85ee231d929a7",
+        build_file_content = MISTUNE_BUILD_FILE,
+        strip_prefix = "mistune-0.7.1",
+    )
+    native.bind(
+        name = "mistune",
+        actual = "@mistune_archive//:mistune",
+    )
+
+    _include_if_not_defined(
+        http_archive,
+        name = "six_archive",
+        urls = ["https://pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz#md5=34eed507548117b2ab523ab14b2f8b55"],
+        sha256 = "105f8d68616f8248e24bf0e9372ef04d3cc10104f1980f54d57b2ce73a5ad56a",
+        build_file_content = SIX_BUILD_FILE,
+        strip_prefix = "six-1.10.0",
+    )
+    native.bind(
+        name = "six",
+        actual = "@six_archive//:six",
+    )

skydoc/BUILD

@@ -2,13 +2,13 @@ licenses(["notice"])  # Apache 2.0
 
 package(default_visibility = ["//visibility:public"])
 
-load("@protobuf//:protobuf.bzl", "py_proto_library")
+load("@com_google_protobuf//:protobuf.bzl", "py_proto_library")
 
 py_proto_library(
     name = "build_pb_py",
     srcs = ["build.proto"],
-    default_runtime = "@protobuf//:protobuf_python",
-    protoc = "@protobuf//:protoc",
+    default_runtime = "@com_google_protobuf//:protobuf_python",
+    protoc = "@com_google_protobuf//:protoc",
 )
 
 py_library(

skylark/skylark.bzl

@@ -17,6 +17,7 @@
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_skylib//:bzl_library.bzl", "StarlarkLibraryInfo")
+load("//:setup.bzl", _skydoc_repositories="skydoc_repositories")
 
 _SKYLARK_FILETYPE = [".bzl"]
 
@@ -170,113 +171,4 @@ Example:
   a set of HTML pages that is ready to be served, set `format = "html"`.
 """
 
-JINJA2_BUILD_FILE = """
-py_library(
-    name = "jinja2",
-    srcs = glob(["jinja2/*.py"]),
-    srcs_version = "PY2AND3",
-    deps = [
-        "@markupsafe_archive//:markupsafe",
-    ],
-    visibility = ["//visibility:public"],
-)
-"""
-
-MARKUPSAFE_BUILD_FILE = """
-py_library(
-    name = "markupsafe",
-    srcs = glob(["markupsafe/*.py"]),
-    srcs_version = "PY2AND3",
-    visibility = ["//visibility:public"],
-)
-"""
-
-MISTUNE_BUILD_FILE = """
-py_library(
-    name = "mistune",
-    srcs = ["mistune.py"],
-    srcs_version = "PY2AND3",
-    visibility = ["//visibility:public"],
-)
-"""
-
-SIX_BUILD_FILE = """
-py_library(
-    name = "six",
-    srcs = ["six.py"],
-    srcs_version = "PY2AND3",
-    visibility = ["//visibility:public"],
-)
-"""
-
-def skydoc_repositories():
-    """Adds the external repositories used by the skylark rules."""
-    git_repository(
-        name = "protobuf",
-        remote = "https://github.com/protocolbuffers/protobuf.git",
-        # Latest tagged version at time of writing is v3.6.1, which doesn't
-        # include fixes for --incompatible_package_name_is_a_function,
-        # --incompatible_new_actions_api, and possibly others.
-        # TODO: Update to a newer tagged version when available.
-        commit = "7b28271a61a3da0a37f6fda399b0c4c86464e5b3",  # 2018-11-16
-    )
-
-    # Protobuf expects an //external:python_headers label which would contain the
-    # Python headers if fast Python protos is enabled. Since we are not using fast
-    # Python protos, bind python_headers to a dummy target.
-    native.bind(
-        name = "python_headers",
-        actual = "//:dummy",
-    )
-
-    http_archive(
-        name = "markupsafe_archive",
-        urls = ["https://pypi.python.org/packages/source/M/MarkupSafe/MarkupSafe-0.23.tar.gz#md5=f5ab3deee4c37cd6a922fb81e730da6e"],
-        sha256 = "a4ec1aff59b95a14b45eb2e23761a0179e98319da5a7eb76b56ea8cdc7b871c3",
-        build_file_content = MARKUPSAFE_BUILD_FILE,
-        strip_prefix = "MarkupSafe-0.23",
-    )
-
-    native.bind(
-        name = "markupsafe",
-        actual = "@markupsafe_archive//:markupsafe",
-    )
-
-    http_archive(
-        name = "jinja2_archive",
-        urls = ["https://pypi.python.org/packages/source/J/Jinja2/Jinja2-2.8.tar.gz#md5=edb51693fe22c53cee5403775c71a99e"],
-        sha256 = "bc1ff2ff88dbfacefde4ddde471d1417d3b304e8df103a7a9437d47269201bf4",
-        build_file_content = JINJA2_BUILD_FILE,
-        strip_prefix = "Jinja2-2.8",
-    )
-
-    native.bind(
-        name = "jinja2",
-        actual = "@jinja2_archive//:jinja2",
-    )
-
-    http_archive(
-        name = "mistune_archive",
-        urls = ["https://pypi.python.org/packages/source/m/mistune/mistune-0.7.1.tar.gz#md5=057bc28bf629d6a1283d680a34ed9d0f"],
-        sha256 = "6076dedf768348927d991f4371e5a799c6a0158b16091df08ee85ee231d929a7",
-        build_file_content = MISTUNE_BUILD_FILE,
-        strip_prefix = "mistune-0.7.1",
-    )
-
-    native.bind(
-        name = "mistune",
-        actual = "@mistune_archive//:mistune",
-    )
-
-    http_archive(
-        name = "six_archive",
-        urls = ["https://pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz#md5=34eed507548117b2ab523ab14b2f8b55"],
-        sha256 = "105f8d68616f8248e24bf0e9372ef04d3cc10104f1980f54d57b2ce73a5ad56a",
-        build_file_content = SIX_BUILD_FILE,
-        strip_prefix = "six-1.10.0",
-    )
-
-    native.bind(
-        name = "six",
-        actual = "@six_archive//:six",
-    )
+skydoc_repositories = _skydoc_repositories