example: add an example for rules_uv (#354)

### Changes are visible to end-users: yes

- Searched for relevant documentation and updated as needed: yes
- Breaking change (forces users to change their own code or config): no
- Suggested release notes appear below: no

### Test plan

- New test cases added

.bazelignore

@@ -1 +1,2 @@
 e2e/
+examples/uv_pip_compile

.github/workflows/ci.yaml

@@ -21,7 +21,7 @@ jobs:
   test:
     uses: bazel-contrib/.github/.github/workflows/bazel.yaml@v6
     with:
-      folders: '[".", "e2e/smoke", "e2e/repository-rule-deps", "e2e/system-interpreter"]'
+      folders: '[".", "e2e/smoke", "e2e/repository-rule-deps", "e2e/system-interpreter", "examples/uv_pip_compile"]'
       # TODO: Build Windows tools and add to toolchain
       # TODO(alex): switch the root folder to bzlmod
       exclude: |
@@ -30,7 +30,9 @@ jobs:
           {"folder": ".", "bazelversion": "6.4.0"},
           {"folder": ".", "bzlmodEnabled": true},
           {"folder": "e2e/repository-rule-deps", "bzlmodEnabled": false},
-          {"folder": "e2e/system-interpreter", "bzlmodEnabled": false}
+          {"folder": "e2e/system-interpreter", "bzlmodEnabled": false},
+          {"folder": "examples/uv_pip_compile", "bzlmodEnabled": false},
+          {"folder": "examples/uv_pip_compile", "bazelversion": "6.4.0"},
         ]
 
   verify-bcr-patches:

examples/uv_pip_compile/BUILD.bazel

@@ -0,0 +1,3 @@
+load("@rules_uv//uv:pip.bzl", "pip_compile")
+
+pip_compile(name = "generate_requirements_txt")

examples/uv_pip_compile/MODULE.bazel

@@ -0,0 +1,18 @@
+"uv pip compile example with py"
+
+bazel_dep(name = "rules_uv", version = "0.14.0", dev_dependency = True)
+bazel_dep(name = "rules_python", version = "0.33.2")
+bazel_dep(name = "aspect_rules_py", version = "0.7.3", dev_dependency = True) 
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python")
+python.toolchain(python_version = "3.9.13")
+
+use_repo(python, "python_3_9_13")
+
+pip = use_extension("@rules_python//python/extensions:pip.bzl", "pip")
+pip.parse(
+    hub_name = "pypi",
+    python_version = "3.9.13",
+    requirements_lock = "//:requirements.txt",
+)
+use_repo(pip, "pypi")

examples/uv_pip_compile/app/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@aspect_rules_py//py:defs.bzl", "py_binary")
+
+py_binary(
+    name = "app",
+    srcs = ["say.py"],
+    deps = [
+        "@pypi//cowsay",
+    ],
+)

examples/uv_pip_compile/app/say.py

@@ -0,0 +1,3 @@
+import cowsay
+
+cowsay.cow('hello py_binary!')

examples/uv_pip_compile/requirements.in

@@ -0,0 +1 @@
+cowsay

examples/uv_pip_compile/requirements.txt

@@ -0,0 +1,7 @@
+# This file was autogenerated by uv via the following command:
+#    bazel run @@//:generate_requirements_txt
+--index-url https://pypi.org/simple
+
+cowsay==6.1 \
+    --hash=sha256:274b1e6fc1b966d53976333eb90ac94cb07a450a700b455af9fbdf882244b30a
+    # via -r requirements.in