1 files changed, 45 insertions, 0 deletions
diff --git a/std/fs/utils.ts b/std/fs/utils.ts
new file mode 100644
index 000000000..f644f4869
--- /dev/null
+++ b/std/fs/utils.ts
@@ -0,0 +1,45 @@
+import * as path from "./path/mod.ts";
+
+/**
+ * Test whether or not `dest` is a sub-directory of `src`
+ * @param src src file path
+ * @param dest dest file path
+ * @param sep path separator
+ */
+export function isSubdir(
+  src: string,
+  dest: string,
+  sep: string = path.sep
+): boolean {
+  if (src === dest) {
+    return false;
+  }
+  const srcArray = src.split(sep);
+  const destArray = dest.split(sep);
+  // see: https://github.com/Microsoft/TypeScript/issues/30821
+  return srcArray.reduce(
+    // @ts-ignore
+    (acc: true, current: string, i: number): boolean => {
+      return acc && destArray[i] === current;
+    },
+    true
+  );
+}
+
+export type PathType = "file" | "dir" | "symlink";
+
+/**
+ * Get a human readable file type string.
+ *
+ * @param fileInfo A FileInfo describes a file and is returned by `stat`,
+ *                 `lstat`
+ */
+export function getFileInfoType(fileInfo: Deno.FileInfo): PathType | undefined {
+  return fileInfo.isFile()
+    ? "file"
+    : fileInfo.isDirectory()
+    ? "dir"
+    : fileInfo.isSymlink()
+    ? "symlink"
+    : undefined;
+}