fix: windows functionality and tests (#334)

There are four issues when running on windows:

1.
#330
2.
#331
3.
#332
4.
#333

This PR fixes 3 and 4.

There are related PRs in bazel-skylib and bazel-starlib. There is no
dependency -- the PRs can close in any order.
- cgrindel/bazel-starlib#446 (fixes 1)
- bazelbuild/bazel-skylib#527 (fixes 2)

### Test results:
Before:
--enable_runfiles: 0 pass
--noenable_runfiles: 0 pass

After this PR:
--enable_runfiles: 52 pass, 19 failures
--noenable_runfiles: 51 pass, 20 failures (17 are doc diff-tests due to
bazel-starlib)

After this PR, together with wip PRs for 1 and 2:
--enable_runfiles: 71 pass, 0 failures
--noenable_runfiles: 51 pass, 20 failures (all due to bazel-starlib)

Author: peakschris

MODULE.bazel

@@ -8,6 +8,12 @@ bazel_dep(name = "rules_python", version = "0.19.0")
 bazel_dep(name = "platforms", version = "0.0.7")
 bazel_dep(name = "cgrindel_bazel_starlib", version = "0.18.0")
 
+# not a direct dependency, but required here for bazel starlib's difftest macros to work
+bazel_dep(
+    name = "buildifier_prebuilt",
+    version = "6.1.2",
+)
+
 register_toolchains("@bazel_tools//tools/python:autodetecting_toolchain")
 
 # Must keep the Bazel version listed in WORKSPACE in sync with those loaded

MODULE.bazel.lock

@@ -12,3 +12,10 @@ common --color=auto --curses=auto
 
 # Enable bzlmod
 common --enable_bzlmod
+
+# Required for windows
+startup --windows_enable_symlinks
+
+# this library requires runfiles for the bzlformat_lint_test
+# but this is off by default on windows. Switch it on.
+common --enable_runfiles

shared.bazelrc

@@ -38,6 +38,10 @@ child_a_bazel_out="${bazel_out}/child_a"
 child_b_bazel_out="${bazel_out}/child_b"
 mkdir -p "${bazel_out}" "${child_a_bazel_out}" "${child_b_bazel_out}" "${parent_bazel_out}"
 
+# Windows requires this for msys to create real symlinks
+# https://superuser.com/questions/1097481/msys2-create-a-sym-link-into-windows-folder-location
+export MSYS=winsymlinks:nativestrict
+
 # Add bazel symlinks
 parent_symlink="${parent_dir}/bazel-parent"
 child_a_symlink="${child_a_dir}/bazel-child_a"