feat: Add common to std/path (#4527)

1 files changed, 47 insertions, 0 deletions

diff --git a/std/path/common_test.ts b/std/path/common_test.ts
new file mode 100644
index 000000000..63dba38b8
--- /dev/null
+++ b/std/path/common_test.ts
@@ -0,0 +1,47 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+const { test } = Deno;
+import { assertEquals } from "../testing/asserts.ts";
+
+import { common } from "./mod.ts";
+
+test({
+  name: "path - common - basic usage",
+  fn() {
+    const actual = common(
+      [
+        "file://deno/cli/js/deno.ts",
+        "file://deno/std/path/mod.ts",
+        "file://deno/cli/js/main.ts",
+      ],
+      "/"
+    );
+    assertEquals(actual, "file://deno/");
+  },
+});
+
+test({
+  name: "path - common - no shared",
+  fn() {
+    const actual = common(
+      ["file://deno/cli/js/deno.ts", "https://deno.land/std/path/mod.ts"],
+      "/"
+    );
+    assertEquals(actual, "");
+  },
+});
+
+test({
+  name: "path - common - windows sep",
+  fn() {
+    const actual = common(
+      [
+        "c:\\deno\\cli\\js\\deno.ts",
+        "c:\\deno\\std\\path\\mod.ts",
+        "c:\\deno\\cli\\js\\main.ts",
+      ],
+      "\\"
+    );
+    assertEquals(actual, "c:\\deno\\");
+  },
+});