feat: copy_to_directory copies files and directories to an output directory

Author: gregmagolan

.bazelrc

@@ -2,6 +2,10 @@
 # Take care to document any settings that you expect users to apply.
 # Settings that apply only to CI are in .github/workflows/ci.bazelrc
 
+# Allow the Bazel server to check directory sources for changes
+# Avoids warning spam with rules_nodejs feature that models node_modules as directories
+# See https://github.com/bazelbuild/rules_nodejs/releases/tag/3.6.0
+startup --host_jvm_args=-DBAZEL_TRACK_SOURCE_DIRECTORIES=1
 
 # Load any settings specific to the current user.
 # .bazelrc.user should appear in .gitignore so that settings are not shared with team members

WORKSPACE

@@ -15,6 +15,12 @@ load("@bazel_skylib//lib:unittest.bzl", "register_unittest_toolchains")
 
 register_unittest_toolchains()
 
+# An external repository for test to use
+local_repository(
+    name = "external_test_repo",
+    path = "./lib/tests/external_test_repo",
+)
+
 ############################################
 # Gazelle, for generating bzl_library targets
 load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")

docs/BUILD.bazel

@@ -2,6 +2,11 @@
 # so that the dependency on stardoc doesn't leak to them.
 load("//lib:docs.bzl", "stardoc_with_diff_test", "update_docs")
 
+stardoc_with_diff_test(
+    bzl_library_target = "//lib/private:copy_to_directory",
+    out_label = "//docs:copy_to_directory.md",
+)
+
 stardoc_with_diff_test(
     bzl_library_target = "//lib:docs",
     out_label = "//docs:docs.md",

docs/copy_to_directory.md

@@ -0,0 +1,50 @@
+<!-- Generated with Stardoc: http://skydoc.bazel.build -->
+
+Copy files and directories to an output directory
+
+<a id="#copy_to_directory"></a>
+
+## copy_to_directory
+
+<pre>
+copy_to_directory(<a href="#copy_to_directory-name">name</a>, <a href="#copy_to_directory-is_windows">is_windows</a>, <a href="#copy_to_directory-replace_prefixes">replace_prefixes</a>, <a href="#copy_to_directory-root_paths">root_paths</a>, <a href="#copy_to_directory-srcs">srcs</a>)
+</pre>
+
+Copies files and directories to an output directory.
+
+Files and directories can be arranged as needed in the output directory using
+the `root_paths` and `replace_prefixes` attributes.
+
+NB: This rule is not yet implemented for Windows
+
+
+**ATTRIBUTES**
+
+
+| Name  | Description | Type | Mandatory | Default |
+| :------------- | :------------- | :------------- | :------------- | :------------- |
+| <a id="copy_to_directory-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
+| <a id="copy_to_directory-is_windows"></a>is_windows |  -   | Boolean | required |  |
+| <a id="copy_to_directory-replace_prefixes"></a>replace_prefixes |  Map of paths prefixes to replace in the output directory path when copying files.<br><br>If the output directory path for a file or directory starts with or is equal to a key in the dict then the matching portion of the output directory path is replaced with the dict value for that key.<br><br>Forward slashes (<code>/</code>) should be used as path separators. The final path segment of the key can be a partial match in the corresponding segment of the output directory path.<br><br>If there are multiple keys that match, the longest match wins.   | <a href="https://bazel.build/docs/skylark/lib/dict.html">Dictionary: String -> String</a> | optional | {} |
+| <a id="copy_to_directory-root_paths"></a>root_paths |  List of paths that are roots in the output directory. If a file or directory being copied is in one of the listed paths or one of its subpaths, the output directory path is the path relative to the root path instead of the path relative to the file's workspace.<br><br>Forward slashes (<code>/</code>) should be used as path separators. Partial matches on the final path segment of a root path against the corresponding segment in the full workspace relative path of a file are not matched.<br><br>If there are multiple root paths that match, the longest match wins.<br><br>Defaults to [package_name()] so that the output directory path of files in the target's package and and sub-packages are relative to the target's package and files outside of that retain their full workspace relative paths.   | List of strings | optional | [] |
+| <a id="copy_to_directory-srcs"></a>srcs |  Files and/or directories to copy into the output directory   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+
+
+<a id="#copy_to_directory_lib.impl"></a>
+
+## copy_to_directory_lib.impl
+
+<pre>
+copy_to_directory_lib.impl(<a href="#copy_to_directory_lib.impl-ctx">ctx</a>)
+</pre>
+
+
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="copy_to_directory_lib.impl-ctx"></a>ctx |  <p align="center"> - </p>   |  none |
+
+

docs/paths.md

@@ -33,7 +33,11 @@ The relative path from frm_file to to_file, including the file name
 to_manifest_path(<a href="#to_manifest_path-ctx">ctx</a>, <a href="#to_manifest_path-file">file</a>)
 </pre>
 
-The runfiles manifest entry for a file
+The runfiles manifest entry path for a file
+
+This is the full runfiles path of a file including its workspace name as
+the first segment. We refert to it as the manifest path as it is the path
+flavor that is used for in the runfiles MANIFEST file.
 
 We must avoid using non-normalized paths (workspace/../other_workspace/path)
 in order to locate entries by their key.
@@ -49,6 +53,34 @@ in order to locate entries by their key.
 
 **RETURNS**
 
-a key that can lookup the path from the runfiles manifest
+The runfiles manifest entry path for a file
+
+
+<a id="#to_workspace_path"></a>
+
+## to_workspace_path
+
+<pre>
+to_workspace_path(<a href="#to_workspace_path-ctx">ctx</a>, <a href="#to_workspace_path-file">file</a>)
+</pre>
+
+The workspace relative path for a file
+
+This is the full runfiles path of a file excluding its workspace name.
+This differs from root path and manifest path as it does not include the
+repository name if the file is from an external repository.
+
+
+**PARAMETERS**
+
+
+| Name  | Description | Default Value |
+| :------------- | :------------- | :------------- |
+| <a id="to_workspace_path-ctx"></a>ctx |  starlark rule execution context   |  none |
+| <a id="to_workspace_path-file"></a>file |  a File object   |  none |
+
+**RETURNS**
+
+The workspace relative path for a file
 
 

lib/BUILD.bazel

@@ -1,7 +1,12 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 
-# For stardoc to reference the files
-exports_files(glob(["*.bzl"]))
+exports_files(
+    glob(["*.bzl"]),
+    visibility = [
+        "//docs:__pkg__",
+        "//lib:__subpackages__",
+    ],
+)
 
 filegroup(
     name = "package_content",

lib/copy_file.bzl

@@ -0,0 +1,35 @@
+# Copyright 2019 The Bazel 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.
+
+# LOCAL MODIFICATIONS
+# this has two PRs patched in on top of the original
+# https://github.com/bazelbuild/bazel-skylib/blob/7b859037a673db6f606661323e74c5d4751595e6/rules/private/copy_file_private.bzl
+# 1) https://github.com/bazelbuild/bazel-skylib/pull/323
+# 2) https://github.com/bazelbuild/bazel-skylib/pull/324
+
+"""A rule that copies a file to another place.
+
+native.genrule() is sometimes used to copy files (often wishing to rename them).
+The 'copy_file' rule does this with a simpler interface than genrule.
+
+The rule uses a Bash command on Linux/macOS/non-Windows, and a cmd.exe command
+on Windows (no Bash is required).
+"""
+
+load(
+    "//lib/private:copy_file.bzl",
+    _copy_file = "copy_file",
+)
+
+copy_file = _copy_file

lib/copy_to_directory.bzl

@@ -0,0 +1,25 @@
+"Public API for copy_to_directory"
+
+load(
+    "//lib/private:copy_to_directory.bzl",
+    lib = "copy_to_directory_lib",
+)
+
+_copy_to_directory = rule(
+    implementation = lib.impl,
+    provides = lib.provides,
+    attrs = lib.attrs,
+)
+
+def copy_to_directory(name, root_paths = None, **kwargs):
+    if root_paths == None:
+        root_paths = [native.package_name()]
+    _copy_to_directory(
+        name = name,
+        root_paths = root_paths,
+        is_windows = select({
+            "@bazel_tools//src/conditions:host_windows": True,
+            "//conditions:default": False,
+        }),
+        **kwargs
+    )

lib/paths.bzl

@@ -4,10 +4,11 @@ load("//lib/private:paths.bzl", "paths")
 
 relative_file = paths.relative_file
 to_manifest_path = paths.to_manifest_path
+to_workspace_path = paths.to_workspace_path
 
 # Bash helper function for looking up runfiles.
 # See windows_utils.bzl for the cmd.exe equivalent.
-# Vendored from 
+# Vendored from
 # https://github.com/bazelbuild/bazel/blob/master/tools/bash/runfiles/runfiles.bash
 BASH_RLOCATION_FUNCTION = r"""
 # --- begin runfiles.bash initialization v2 ---

lib/private/BUILD.bazel

@@ -1,5 +1,10 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 
+exports_files(
+    glob(["*.bzl"]),
+    visibility = ["//docs:__pkg__"],
+)
+
 filegroup(
     name = "package_content",
     srcs = glob([
@@ -9,6 +14,16 @@ filegroup(
     visibility = ["//lib:__pkg__"],
 )
 
+bzl_library(
+    name = "copy_to_directory",
+    srcs = ["copy_to_directory.bzl"],
+    visibility = ["//docs:__pkg__"],
+    deps = [
+        ":paths",
+        "@bazel_skylib//lib:paths",
+    ],
+)
+
 bzl_library(
     name = "params_file",
     srcs = ["params_file.bzl"],