Swift: teach bazel to install python dependencies

Author: AlexDenisov

.github/workflows/swift-codegen.yml

@@ -15,13 +15,6 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/fetch-codeql
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
-        with:
-          python-version: '~3.8'
-          cache: 'pip'
-      - name: Install python dependencies
-        run: |
-          pip install -r swift/codegen/requirements.txt
       - name: Run unit tests
         run: |
           bazel test //swift/codegen/test --test_output=errors

.github/workflows/swift-qltest.yml

@@ -29,13 +29,6 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/fetch-codeql
       - uses: bazelbuild/setup-bazelisk@v2
-      - uses: actions/setup-python@v3
-        with:
-          python-version: '~3.8'
-          cache: 'pip'
-      - name: Install python dependencies
-        run: |
-          pip install -r codegen/requirements.txt
       - name: Build Swift extractor
         run: |
           bazel run //swift:create-extractor-pack

misc/bazel/workspace.bzl

@@ -45,3 +45,14 @@ def codeql_workspace(repository_name = "codeql"):
             "https://github.com/bazelbuild/platforms/releases/download/0.0.3/platforms-0.0.3.tar.gz",
         ],
     )
+
+    maybe(
+        repo_rule = http_archive,
+        name = "rules_python",
+        sha256 = "cdf6b84084aad8f10bf20b46b77cb48d83c319ebe6458a18e9d2cebf57807cdd",
+        strip_prefix = "rules_python-0.8.1",
+        urls = [
+            "https://github.com/bazelbuild/rules_python/archive/refs/tags/0.8.1.tar.gz",
+        ],
+    )
+

misc/bazel/workspace_deps.bzl

@@ -1,4 +1,9 @@
 load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")
+load("@rules_python//python:pip.bzl", "pip_install")
 
-def codeql_workspace_deps():
+def codeql_workspace_deps(repository_name = "codeql"):
+    pip_install(
+       name = "swift_codegen_deps",
+       requirements = "@%s//swift/codegen:requirements.txt" % repository_name,
+    )
     rules_pkg_dependencies()

swift/codegen/lib/BUILD.bazel

@@ -1,5 +1,11 @@
+load("@swift_codegen_deps//:requirements.bzl", "requirement")
 py_library(
     name = "lib",
     srcs = glob(["*.py"]),
+    deps = [
+        requirement("pystache"),
+        requirement("pyyaml"),
+        requirement("inflection"),
+    ],
     visibility = ["//swift/codegen:__subpackages__"],
 )

swift/codegen/test/BUILD.bazel

@@ -1,8 +1,13 @@
+load("@swift_codegen_deps//:requirements.bzl", "requirement")
+
 py_library(
     name = "utils",
     testonly = True,
     srcs = ["utils.py"],
-    deps = ["//swift/codegen/lib"],
+    deps = [
+        "//swift/codegen/lib",
+        requirement("pytest"),
+    ],
 )
 
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