Add mkdirp (denoland/deno_std#59)

Original: 7a3c70e74b

mkdirp/test.ts

@@ -0,0 +1,30 @@
+import { cwd, lstat, makeTempDirSync, removeAll, FileInfo } from "deno";
+import { test, assert } from "https://deno.land/x/testing/testing.ts";
+import { mkdirp } from "./mkdirp.ts";
+
+let root: string = `${cwd()}/${Date.now()}`; //makeTempDirSync();
+
+test(async function createsNestedDirs(): Promise<void> {
+  const leaf: string = `${root}/levelx/levely`;
+  await mkdirp(leaf);
+  const info: FileInfo = await lstat(leaf);
+  assert(info.isDirectory());
+  await removeAll(root);
+});
+
+test(async function handlesAnyPathSeparator(): Promise<void> {
+  const leaf: string = `${root}\\levelx\\levely`;
+  await mkdirp(leaf);
+  const info: FileInfo = await lstat(leaf.replace(/\\/g, "/"));
+  assert(info.isDirectory());
+  await removeAll(root);
+});
+
+test(async function failsNonDir(): Promise<void> {
+  try {
+    await mkdirp("./test.ts/fest.fs");
+  } catch (err) {
+    // TODO: assert caught DenoError of kind NOT_A_DIRECTORY or similar
+    assert(err);
+  }
+});