fix: use custom realpath function in copy_directory and copy_to_directory since github.com/yookoala/realpath has bugs on Windows (#338)

deps.bzl

@@ -13,7 +13,6 @@ def go_dependencies():
         sum = "h1:HTuxyug8GyFbRkrffIpzNCSK4luc0TY3wzXvzIZhEXc=",
         version = "v4.6.0",
     )
-
     go_repository(
         name = "com_github_google_go_cmp",
         build_file_proto_mode = "disable_global",
@@ -21,14 +20,6 @@ def go_dependencies():
         sum = "h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=",
         version = "v0.5.8",
     )
-    go_repository(
-        name = "com_github_yookoala_realpath",
-        build_file_proto_mode = "disable_global",
-        importpath = "github.com/yookoala/realpath",
-        sum = "h1:7OA9pj4FZd+oZDsyvXWQvjn5oBdcHRTV44PpdMSuImQ=",
-        version = "v1.0.0",
-    )
-
     go_repository(
         name = "org_golang_x_exp",
         build_file_proto_mode = "disable_global",

go.mod

@@ -4,6 +4,5 @@ go 1.19
 
 require (
 	github.com/bmatcuk/doublestar/v4 v4.6.0
-	github.com/yookoala/realpath v1.0.0
 	golang.org/x/exp v0.0.0-20221230185412-738e83a70c30
 )

go.sum

@@ -1,6 +1,4 @@
 github.com/bmatcuk/doublestar/v4 v4.6.0 h1:HTuxyug8GyFbRkrffIpzNCSK4luc0TY3wzXvzIZhEXc=
 github.com/bmatcuk/doublestar/v4 v4.6.0/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
-github.com/yookoala/realpath v1.0.0 h1:7OA9pj4FZd+oZDsyvXWQvjn5oBdcHRTV44PpdMSuImQ=
-github.com/yookoala/realpath v1.0.0/go.mod h1:gJJMA9wuX7AcqLy1+ffPatSCySA1FQ2S8Ya9AIoYBpE=
 golang.org/x/exp v0.0.0-20221230185412-738e83a70c30 h1:m9O6OTJ627iFnN2JIWfdqlZCzneRO6EEBsHXI25P8ws=
 golang.org/x/exp v0.0.0-20221230185412-738e83a70c30/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=

tools/common/file.go

@@ -1,6 +1,9 @@
 package common
 
 import (
+	"fmt"
+	"os"
+	"path"
 	"path/filepath"
 )
 
@@ -14,3 +17,27 @@ func FileRel(basepath, targpath string) (string, error) {
 
 	return filepath.ToSlash(r), nil
 }
+
+// github.com/yookoala/realpath has bugs on Windows;
+// this function assumes that the path passed in is a symlink
+func Realpath(p string) (string, error) {
+	t, err := os.Readlink(p)
+	if err != nil {
+		return "", fmt.Errorf("readlink %s failed: %w", p, err)
+	}
+
+	if !path.IsAbs(t) {
+		t = path.Join(path.Dir(p), t)
+	}
+
+	info, err := os.Lstat(t)
+	if err != nil {
+		return "", fmt.Errorf("lstat %s failed: %w", p, err)
+	}
+
+	if info.Mode()&os.ModeSymlink == os.ModeSymlink {
+		return Realpath(t)
+	}
+
+	return t, nil
+}

tools/copy_directory/BUILD.bazel

@@ -5,10 +5,7 @@ go_library(
     srcs = ["main.go"],
     importpath = "github.com/aspect-build/bazel-lib/tools/copy_directory",
     visibility = ["//visibility:public"],
-    deps = [
-        "//tools/common",
-        "@com_github_yookoala_realpath//:go_default_library",
-    ],
+    deps = ["//tools/common"],
 )
 
 go_binary(

tools/copy_directory/main.go

@@ -9,7 +9,6 @@ import (
 	"sync"
 
 	"github.com/aspect-build/bazel-lib/tools/common"
-	"github.com/yookoala/realpath"
 )
 
 type pathSet map[string]bool
@@ -46,7 +45,7 @@ func copyDir(src string, dst string) error {
 
 		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
 			// symlink to directories are intentionally never followed by filepath.Walk to avoid infinite recursion
-			linkPath, err := realpath.Realpath(p)
+			linkPath, err := common.Realpath(p)
 			if err != nil {
 				return err
 			}

tools/copy_to_directory/BUILD.bazel

@@ -8,7 +8,6 @@ go_library(
     deps = [
         "//tools/common",
         "@com_github_bmatcuk_doublestar_v4//:doublestar",
-        "@com_github_yookoala_realpath//:go_default_library",
         "@org_golang_x_exp//maps",
     ],
 )

tools/copy_to_directory/main.go

@@ -14,7 +14,6 @@ import (
 
 	"github.com/aspect-build/bazel-lib/tools/common"
 	"github.com/bmatcuk/doublestar/v4"
-	"github.com/yookoala/realpath"
 	"golang.org/x/exp/maps"
 )
 
@@ -155,7 +154,7 @@ func copyDir(cfg *config, srcPaths pathSet, file fileInfo) error {
 
 		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
 			// symlink to directories are intentionally never followed by filepath.Walk to avoid infinite recursion
-			linkPath, err := realpath.Realpath(p)
+			linkPath, err := common.Realpath(p)
 			if err != nil {
 				return err
 			}
@@ -341,7 +340,7 @@ func copyPaths(cfg *config) error {
 		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
 			// On Windows, filepath.WalkDir doesn't like directory symlinks so we must
 			// call filepath.WalkDir on the realpath
-			realpath, err := realpath.Realpath(file.Path)
+			realpath, err := common.Realpath(file.Path)
 			if err != nil {
 				return err
 			}