Add Deno.realpath (#3404)

cli/js/realpath_test.ts

@@ -0,0 +1,91 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { testPerm, assert, assertEquals } from "./test_util.ts";
+
+testPerm({ read: true }, function realpathSyncSuccess(): void {
+  const incompletePath = "cli/tests/fixture.json";
+  const realPath = Deno.realpathSync(incompletePath);
+  assert(realPath.startsWith("/"));
+  assert(realPath.endsWith(incompletePath));
+});
+
+if (Deno.build.os !== "win") {
+  testPerm({ read: true, write: true }, function realpathSyncSymlink(): void {
+    const testDir = Deno.makeTempDirSync();
+    const target = testDir + "/target";
+    const symlink = testDir + "/symln";
+    Deno.mkdirSync(target);
+    Deno.symlinkSync(target, symlink);
+    const targetPath = Deno.realpathSync(symlink);
+    assert(targetPath.startsWith("/"));
+    assert(targetPath.endsWith("/target"));
+  });
+}
+
+testPerm({ read: false }, function realpathSyncPerm(): void {
+  let caughtError = false;
+  try {
+    Deno.realpathSync("some_file");
+  } catch (e) {
+    caughtError = true;
+    assertEquals(e.kind, Deno.ErrorKind.PermissionDenied);
+    assertEquals(e.name, "PermissionDenied");
+  }
+  assert(caughtError);
+});
+
+testPerm({ read: true }, function realpathSyncNotFound(): void {
+  let caughtError = false;
+  try {
+    Deno.realpathSync("bad_filename");
+  } catch (e) {
+    caughtError = true;
+    assertEquals(e.kind, Deno.ErrorKind.NotFound);
+  }
+  assert(caughtError);
+});
+
+testPerm({ read: true }, async function realpathSuccess(): Promise<void> {
+  const incompletePath = "cli/tests/fixture.json";
+  const realPath = await Deno.realpath(incompletePath);
+  assert(realPath.startsWith("/"));
+  assert(realPath.endsWith(incompletePath));
+});
+
+if (Deno.build.os !== "win") {
+  testPerm(
+    { read: true, write: true },
+    async function realpathSymlink(): Promise<void> {
+      const testDir = Deno.makeTempDirSync();
+      const target = testDir + "/target";
+      const symlink = testDir + "/symln";
+      Deno.mkdirSync(target);
+      Deno.symlinkSync(target, symlink);
+      const targetPath = await Deno.realpath(symlink);
+      assert(targetPath.startsWith("/"));
+      assert(targetPath.endsWith("/target"));
+    }
+  );
+}
+
+testPerm({ read: false }, async function realpathPerm(): Promise<void> {
+  let caughtError = false;
+  try {
+    await Deno.realpath("some_file");
+  } catch (e) {
+    caughtError = true;
+    assertEquals(e.kind, Deno.ErrorKind.PermissionDenied);
+    assertEquals(e.name, "PermissionDenied");
+  }
+  assert(caughtError);
+});
+
+testPerm({ read: true }, async function realpathNotFound(): Promise<void> {
+  let caughtError = false;
+  try {
+    await Deno.realpath("bad_filename");
+  } catch (e) {
+    caughtError = true;
+    assertEquals(e.kind, Deno.ErrorKind.NotFound);
+  }
+  assert(caughtError);
+});