1 files changed, 90 insertions, 0 deletions
diff --git a/std/fs/path/extname_test.ts b/std/fs/path/extname_test.ts
new file mode 100644
index 000000000..336d6b0b2
--- /dev/null
+++ b/std/fs/path/extname_test.ts
@@ -0,0 +1,90 @@
+// Copyright the Browserify authors. MIT License.
+// Ported from https://github.com/browserify/path-browserify/
+
+import { test } from "../../testing/mod.ts";
+import { assertEquals } from "../../testing/asserts.ts";
+import * as path from "./mod.ts";
+
+const slashRE = /\//g;
+
+const pairs = [
+  ["", ""],
+  ["/path/to/file", ""],
+  ["/path/to/file.ext", ".ext"],
+  ["/path.to/file.ext", ".ext"],
+  ["/path.to/file", ""],
+  ["/path.to/.file", ""],
+  ["/path.to/.file.ext", ".ext"],
+  ["/path/to/f.ext", ".ext"],
+  ["/path/to/..ext", ".ext"],
+  ["/path/to/..", ""],
+  ["file", ""],
+  ["file.ext", ".ext"],
+  [".file", ""],
+  [".file.ext", ".ext"],
+  ["/file", ""],
+  ["/file.ext", ".ext"],
+  ["/.file", ""],
+  ["/.file.ext", ".ext"],
+  [".path/file.ext", ".ext"],
+  ["file.ext.ext", ".ext"],
+  ["file.", "."],
+  [".", ""],
+  ["./", ""],
+  [".file.ext", ".ext"],
+  [".file", ""],
+  [".file.", "."],
+  [".file..", "."],
+  ["..", ""],
+  ["../", ""],
+  ["..file.ext", ".ext"],
+  ["..file", ".file"],
+  ["..file.", "."],
+  ["..file..", "."],
+  ["...", "."],
+  ["...ext", ".ext"],
+  ["....", "."],
+  ["file.ext/", ".ext"],
+  ["file.ext//", ".ext"],
+  ["file/", ""],
+  ["file//", ""],
+  ["file./", "."],
+  ["file.//", "."]
+];
+
+test(function extname() {
+  pairs.forEach(function(p) {
+    const input = p[0];
+    const expected = p[1];
+    assertEquals(expected, path.posix.extname(input));
+  });
+
+  // On *nix, backslash is a valid name component like any other character.
+  assertEquals(path.posix.extname(".\\"), "");
+  assertEquals(path.posix.extname("..\\"), ".\\");
+  assertEquals(path.posix.extname("file.ext\\"), ".ext\\");
+  assertEquals(path.posix.extname("file.ext\\\\"), ".ext\\\\");
+  assertEquals(path.posix.extname("file\\"), "");
+  assertEquals(path.posix.extname("file\\\\"), "");
+  assertEquals(path.posix.extname("file.\\"), ".\\");
+  assertEquals(path.posix.extname("file.\\\\"), ".\\\\");
+});
+
+test(function extnameWin32() {
+  pairs.forEach(function(p) {
+    const input = p[0].replace(slashRE, "\\");
+    const expected = p[1];
+    assertEquals(expected, path.win32.extname(input));
+    assertEquals(expected, path.win32.extname("C:" + input));
+  });
+
+  // On Windows, backslash is a path separator.
+  assertEquals(path.win32.extname(".\\"), "");
+  assertEquals(path.win32.extname("..\\"), "");
+  assertEquals(path.win32.extname("file.ext\\"), ".ext");
+  assertEquals(path.win32.extname("file.ext\\\\"), ".ext");
+  assertEquals(path.win32.extname("file\\"), "");
+  assertEquals(path.win32.extname("file\\\\"), "");
+  assertEquals(path.win32.extname("file.\\"), ".");
+  assertEquals(path.win32.extname("file.\\\\"), ".");
+});