Implement deno.symlink() (#742)

4 files changed, 129 insertions, 0 deletions

diff --git a/js/deno.ts b/js/deno.ts
index 7ff763e8d..7d52441ec 100644
--- a/js/deno.ts
+++ b/js/deno.ts
@@ -8,6 +8,7 @@ export { removeSync, remove, removeAllSync, removeAll } from "./remove";
 export { readFileSync, readFile } from "./read_file";
 export { renameSync, rename } from "./rename";
 export { FileInfo, statSync, lstatSync, stat, lstat } from "./stat";
+export { symlinkSync, symlink } from "./symlink";
 export { writeFileSync, writeFile } from "./write_file";
 export { ErrorKind, DenoError } from "./errors";
 export { libdeno } from "./libdeno";
diff --git a/js/symlink.ts b/js/symlink.ts
new file mode 100644
index 000000000..225dae5f0
--- /dev/null
+++ b/js/symlink.ts
@@ -0,0 +1,56 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+import * as fbs from "gen/msg_generated";
+import { flatbuffers } from "flatbuffers";
+import * as dispatch from "./dispatch";
+import * as util from "./util";
+
+/**
+ * Synchronously creates newname as a symbolic link to oldname.
+ * The type argument can be set to 'dir' or 'file' and is only
+ * available on Windows (ignored on other platforms).
+ *
+ *     import { symlinkSync } from "deno";
+ *     symlinkSync("old/name", "new/name");
+ */
+export function symlinkSync(
+  oldname: string,
+  newname: string,
+  type?: string
+): void {
+  dispatch.sendSync(...req(oldname, newname, type));
+}
+
+/**
+ * Creates newname as a symbolic link to oldname.
+ * The type argument can be set to 'dir' or 'file' and is only
+ * available on Windows (ignored on other platforms).
+ *
+ *     import { symlink } from "deno";
+ *     await symlink("old/name", "new/name");
+ */
+export async function symlink(
+  oldname: string,
+  newname: string,
+  type?: string
+): Promise<void> {
+  await dispatch.sendAsync(...req(oldname, newname, type));
+}
+
+function req(
+  oldname: string,
+  newname: string,
+  type?: string
+): [flatbuffers.Builder, fbs.Any, flatbuffers.Offset] {
+  // TODO Use type for Windows.
+  if (type) {
+    return util.notImplemented();
+  }
+  const builder = new flatbuffers.Builder();
+  const oldname_ = builder.createString(oldname);
+  const newname_ = builder.createString(newname);
+  fbs.Symlink.startSymlink(builder);
+  fbs.Symlink.addOldname(builder, oldname_);
+  fbs.Symlink.addNewname(builder, newname_);
+  const msg = fbs.Symlink.endSymlink(builder);
+  return [builder, fbs.Any.Symlink, msg];
+}
diff --git a/js/symlink_test.ts b/js/symlink_test.ts
new file mode 100644
index 000000000..a3203ac6e
--- /dev/null
+++ b/js/symlink_test.ts
@@ -0,0 +1,71 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+import { test, testPerm, assert, assertEqual } from "./test_util.ts";
+import * as deno from "deno";
+
+testPerm({ write: true }, function symlinkSyncSuccess() {
+  const testDir = deno.makeTempDirSync() + "/test-symlink-sync";
+  const oldname = testDir + "/oldname";
+  const newname = testDir + "/newname";
+  deno.mkdirSync(oldname);
+  let errOnWindows;
+  // Just for now, until we implement symlink for Windows.
+  try {
+    deno.symlinkSync(oldname, newname);
+  } catch (e) {
+    errOnWindows = e;
+  }
+  if (errOnWindows) {
+    assertEqual(errOnWindows.kind, deno.ErrorKind.Other);
+    assertEqual(errOnWindows.message, "Not implemented");
+  } else {
+    const newNameInfoLStat = deno.lstatSync(newname);
+    const newNameInfoStat = deno.statSync(newname);
+    assert(newNameInfoLStat.isSymlink());
+    assert(newNameInfoStat.isDirectory());
+  }
+});
+
+testPerm({ write: false }, function symlinkSyncPerm() {
+  let err;
+  try {
+    deno.symlinkSync("oldbaddir", "newbaddir");
+  } catch (e) {
+    err = e;
+  }
+  assertEqual(err.kind, deno.ErrorKind.PermissionDenied);
+  assertEqual(err.name, "PermissionDenied");
+});
+
+// Just for now, until we implement symlink for Windows.
+testPerm({ write: true }, function symlinkSyncNotImplemented() {
+  let err;
+  try {
+    deno.symlinkSync("oldname", "newname", "dir");
+  } catch (e) {
+    err = e;
+  }
+  assertEqual(err.message, "Not implemented");
+});
+
+testPerm({ write: true }, async function symlinkSuccess() {
+  const testDir = deno.makeTempDirSync() + "/test-symlink";
+  const oldname = testDir + "/oldname";
+  const newname = testDir + "/newname";
+  deno.mkdirSync(oldname);
+  let errOnWindows;
+  // Just for now, until we implement symlink for Windows.
+  try {
+    await deno.symlink(oldname, newname);
+  } catch (e) {
+    errOnWindows = e;
+  }
+  if (errOnWindows) {
+    assertEqual(errOnWindows.kind, deno.ErrorKind.Other);
+    assertEqual(errOnWindows.message, "Not implemented");
+  } else {
+    const newNameInfoLStat = deno.lstatSync(newname);
+    const newNameInfoStat = deno.statSync(newname);
+    assert(newNameInfoLStat.isSymlink());
+    assert(newNameInfoStat.isDirectory());
+  }
+});
diff --git a/js/unit_tests.ts b/js/unit_tests.ts
index 4f7b9681d..f1eed319e 100644
--- a/js/unit_tests.ts
+++ b/js/unit_tests.ts
@@ -13,3 +13,4 @@ import "./stat_test.ts";
 import "./rename_test.ts";
 import "./blob_test.ts";
 import "./timers_test.ts";
+import "./symlink_test.ts";