fix: fix pathing issue in new copy_to_directory binary tool on Windows (#334)

lib/BUILD.bazel

@@ -193,8 +193,8 @@ bzl_library(
     srcs = ["repositories.bzl"],
     deps = [
         ":utils",
-        "//lib/private/docs:coreutils_toolchain",
         "//lib/private/docs:copy_to_directory_toolchain",
+        "//lib/private/docs:coreutils_toolchain",
         "//lib/private/docs:jq_toolchain",
         "//lib/private/docs:local_config_platform",
         "//lib/private/docs:yq_toolchain",

lib/tests/coreutils/BUILD.bazel

@@ -14,11 +14,10 @@ diff_test(
     file2 = ":ls",
 )
 
-
 genrule(
     name = "sha256sum",
-    outs = ["sha256sum.txt"],
     srcs = ["test.bin"],
+    outs = ["sha256sum.txt"],
     cmd = "$(COREUTILS_BIN) sha256sum $(location :test.bin) > $@",
     toolchains = ["@coreutils_toolchains//:resolved_toolchain"],
 )
@@ -29,11 +28,10 @@ assert_contains(
     expected = """9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08  lib/tests/coreutils/test.bin""",
 )
 
-
 genrule(
     name = "sha512sum",
-    outs = ["sha512sum.txt"],
     srcs = ["test.bin"],
+    outs = ["sha512sum.txt"],
     cmd = "$(COREUTILS_BIN) sha512sum $(location :test.bin) > $@",
     toolchains = ["@coreutils_toolchains//:resolved_toolchain"],
 )
@@ -46,8 +44,8 @@ assert_contains(
 
 genrule(
     name = "wc",
-    outs = ["wc.txt"],
     srcs = ["test.bin"],
+    outs = ["wc.txt"],
     cmd = "$(COREUTILS_BIN) wc $(location :test.bin) > $@",
     toolchains = ["@coreutils_toolchains//:resolved_toolchain"],
 )
@@ -56,4 +54,4 @@ assert_contains(
     name = "test_wc",
     actual = "wc.txt",
     expected = """0 1 4 lib/tests/coreutils/test.bin""",
-)
+)

tools/common/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
     name = "common",
     srcs = [
         "copy.go",
+        "file.go",
         "stamp.go",
         "version.go",
     ],

tools/common/file.go

@@ -0,0 +1,14 @@
+package common
+
+import "path/filepath"
+
+// Same as filepath.Rel except that it normalizes result to forward slashes
+// slashes since filepath.Rel will convert to system slashes
+func FileRel(basepath, targpath string) (string, error) {
+	r, err := filepath.Rel(basepath, targpath)
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.ToSlash(r), nil
+}

tools/copy_directory/main.go

@@ -27,7 +27,7 @@ func copyDir(src string, dst string) error {
 			return err
 		}
 
-		r, err := filepath.Rel(src, p)
+		r, err := common.FileRel(src, p)
 		if err != nil {
 			return err
 		}

tools/copy_to_directory/main.go

@@ -142,6 +142,11 @@ func copyDir(cfg *config, srcPaths pathSet, file fileInfo) error {
 			return err
 		}
 
+		r, err := common.FileRel(file.Path, p)
+		if err != nil {
+			return err
+		}
+
 		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
 			// symlink to directories are intentionally never followed by filepath.Walk to avoid infinite recursion
 			linkPath, err := os.Readlink(p)
@@ -174,10 +179,6 @@ func copyDir(cfg *config, srcPaths pathSet, file fileInfo) error {
 				return copyDir(cfg, srcPaths, f)
 			} else {
 				// symlink points to a regular file
-				r, err := filepath.Rel(file.Path, p)
-				if err != nil {
-					return fmt.Errorf("failed to walk directory %s: %w", file.Path, err)
-				}
 				f := fileInfo{
 					Package:       file.Package,
 					Path:          linkPath,
@@ -193,10 +194,6 @@ func copyDir(cfg *config, srcPaths pathSet, file fileInfo) error {
 		}
 
 		// a regular file
-		r, err := filepath.Rel(file.Path, p)
-		if err != nil {
-			return fmt.Errorf("failed to walk directory %s: %w", file.Path, err)
-		}
 		f := fileInfo{
 			Package:       file.Package,
 			Path:          p,