feat: Return null on error in Deno.dir() (denoland#3531)

gcollazo · Dec 21, 2019 · b7b0668 · b7b0668
1 parent e8d82a6
commit b7b0668
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Showing 3 changed files with 16 additions and 9 deletions.
diff --git a/cli/js/lib.deno_runtime.d.ts b/cli/js/lib.deno_runtime.d.ts
@@ -74,6 +74,8 @@ declare namespace Deno {
  /**
  * Returns the user and platform specific directories.
  * Requires the `--allow-env` flag.
+ * Returns null if there is no applicable directory or if any other error
+ * occurs.
  *
  * Argument values: "home", "cache", "config", "data", "data_local", "audio",
  * "desktop", "document", "download", "font", "picture", "public", "template",
@@ -170,7 +172,7 @@ declare namespace Deno {
  * | macOS | `$HOME`/Movies | /Users/Alice/Movies |
  * | Windows | `{FOLDERID_Videos}` | C:\Users\Alice\Videos |
  */
- export function dir(kind: DirKind): string;
+ export function dir(kind: DirKind): string | null;
 
  /**
  * Returns the path to the current deno executable.

diff --git a/cli/js/os.ts b/cli/js/os.ts
@@ -2,6 +2,7 @@
 import { core } from "./core.ts";
 import * as dispatch from "./dispatch.ts";
 import { sendSync } from "./dispatch_json.ts";
+import { ErrorKind } from "./errors.ts";
 import { assert } from "./util.ts";
 import * as util from "./util.ts";
 import { window } from "./window.ts";
@@ -147,6 +148,8 @@ type DirKind =
 /**
  * Returns the user and platform specific directories.
  * Requires the `--allow-env` flag.
+ * Returns null if there is no applicable directory or if any other error
+ * occurs.
  *
  * Argument values: "home", "cache", "config", "data", "data_local", "audio",
  * "desktop", "document", "download", "font", "picture", "public", "template",
@@ -243,8 +246,15 @@ type DirKind =
  * | macOS | `$HOME`/Movies | /Users/Alice/Movies |
  * | Windows | `{FOLDERID_Videos}` | C:\Users\Alice\Videos |
  */
-export function dir(kind: DirKind): string {
- return sendSync(dispatch.OP_GET_DIR, { kind });
+export function dir(kind: DirKind): string | null {
+ try {
+ return sendSync(dispatch.OP_GET_DIR, { kind });
+ } catch (error) {
+ if (error.kind == ErrorKind.PermissionDenied) {
+ throw error;
+ }
+ return null;
+ }
 }
 
 /**

diff --git a/cli/js/os_test.ts b/cli/js/os_test.ts
@@ -242,12 +242,7 @@ testPerm({ env: true }, function getDir(): void {
  if (r.shouldHaveValue) {
  assertNotEquals(Deno.dir(s.kind), "");
  } else {
- // if not support your platform. it should throw an error
- assertThrows(
- () => Deno.dir(s.kind),
- Deno.DenoError,
- `Could not get user ${s.kind} directory.`
- );
+ assertEquals(Deno.dir(s.kind), null);
  }
  }
  }