fix permission errors are swallowed by fs.emptyDir (#3501)

std/fs/empty_dir.ts

@@ -1,26 +1,40 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { join } from "../path/mod.ts";
+const {
+  readDir,
+  readDirSync,
+  mkdir,
+  mkdirSync,
+  remove,
+  removeSync,
+  ErrorKind
+} = Deno;
 /**
  * Ensures that a directory is empty.
  * Deletes directory contents if the directory is not empty.
  * If the directory does not exist, it is created.
  * The directory itself is not deleted.
+ * Requires the `--allow-read` and `--alow-write` flag.
  */
 export async function emptyDir(dir: string): Promise<void> {
-  let items: Deno.FileInfo[] = [];
   try {
-    items = await Deno.readDir(dir);
+    const items = await readDir(dir);
-  } catch {
+
-    // if not exist. then create it
-    await Deno.mkdir(dir, true);
-    return;
-  }
     while (items.length) {
       const item = items.shift();
       if (item && item.name) {
-      const fn = dir + "/" + item.name;
+        const filepath = join(dir, item.name);
-      await Deno.remove(fn, { recursive: true });
+        await remove(filepath, { recursive: true });
       }
     }
+  } catch (err) {
+    if ((err as Deno.DenoError<Deno.ErrorKind>).kind !== ErrorKind.NotFound) {
+      throw err;
+    }
+
+    // if not exist. then create it
+    await mkdir(dir, true);
+  }
 }
 
 /**
@@ -28,21 +42,26 @@ export async function emptyDir(dir: string): Promise<void> {
  * Deletes directory contents if the directory is not empty.
  * If the directory does not exist, it is created.
  * The directory itself is not deleted.
+ * Requires the `--allow-read` and `--alow-write` flag.
  */
 export function emptyDirSync(dir: string): void {
-  let items: Deno.FileInfo[] = [];
   try {
-    items = Deno.readDirSync(dir);
+    const items = readDirSync(dir);
-  } catch {
+
-    // if not exist. then create it
+    // if directory already exist. then remove it's child item.
-    Deno.mkdirSync(dir, true);
-    return;
-  }
     while (items.length) {
       const item = items.shift();
       if (item && item.name) {
-      const fn = dir + "/" + item.name;
+        const filepath = join(dir, item.name);
-      Deno.removeSync(fn, { recursive: true });
+        removeSync(filepath, { recursive: true });
       }
     }
+  } catch (err) {
+    if ((err as Deno.DenoError<Deno.ErrorKind>).kind !== ErrorKind.NotFound) {
+      throw err;
+    }
+    // if not exist. then create it
+    mkdirSync(dir, true);
+    return;
+  }
 }

std/fs/empty_dir_test.ts

@@ -123,3 +123,116 @@ test(function emptyDirSyncIfItExist(): void {
     Deno.removeSync(testDir, { recursive: true });
   }
 });
+
+test(async function emptyDirPermission(): Promise<void> {
+  interface Scenes {
+    read: boolean; // --allow-read
+    write: boolean; // --allow-write
+    async: boolean;
+    output: string;
+  }
+
+  const testfolder = path.join(testdataDir, "testfolder");
+
+  await Deno.mkdir(testfolder);
+
+  await Deno.writeFile(
+    path.join(testfolder, "child.txt"),
+    new TextEncoder().encode("hello world")
+  );
+
+  const scenes: Scenes[] = [
+    // 1
+    {
+      read: false,
+      write: false,
+      async: true,
+      output: "run again with the --allow-read flag"
+    },
+    {
+      read: false,
+      write: false,
+      async: false,
+      output: "run again with the --allow-read flag"
+    },
+    // 2
+    {
+      read: true,
+      write: false,
+      async: true,
+      output: "run again with the --allow-write flag"
+    },
+    {
+      read: true,
+      write: false,
+      async: false,
+      output: "run again with the --allow-write flag"
+    },
+    // 3
+    {
+      read: false,
+      write: true,
+      async: true,
+      output: "run again with the --allow-read flag"
+    },
+    {
+      read: false,
+      write: true,
+      async: false,
+      output: "run again with the --allow-read flag"
+    },
+    // 4
+    {
+      read: true,
+      write: true,
+      async: true,
+      output: "success"
+    },
+    {
+      read: true,
+      write: true,
+      async: false,
+      output: "success"
+    }
+  ];
+
+  try {
+    for (const s of scenes) {
+      console.log(
+        `test ${s.async ? "emptyDir" : "emptyDirSync"}("testdata/testfolder") ${
+          s.read ? "with" : "without"
+        } --allow-read & ${s.write ? "with" : "without"} --allow-write`
+      );
+
+      const args = [Deno.execPath(), "run"];
+
+      if (s.read) {
+        args.push("--allow-read");
+      }
+
+      if (s.write) {
+        args.push("--allow-write");
+      }
+
+      args.push(
+        path.join(testdataDir, s.async ? "empty_dir.ts" : "empty_dir_sync.ts")
+      );
+      args.push("testfolder");
+
+      const { stdout } = Deno.run({
+        stdout: "piped",
+        cwd: testdataDir,
+        args: args
+      });
+
+      const output = await Deno.readAll(stdout);
+
+      assertEquals(new TextDecoder().decode(output), s.output);
+    }
+  } catch (err) {
+    await Deno.remove(testfolder, { recursive: true });
+    throw err;
+  }
+
+  // done
+});

std/fs/testdata/empty_dir.ts

@@ -0,0 +1,9 @@
+import { emptyDir } from "../empty_dir.ts";
+
+emptyDir(Deno.args[1])
+  .then(() => {
+    Deno.stdout.write(new TextEncoder().encode("success"))
+  })
+  .catch((err) => {
+    Deno.stdout.write(new TextEncoder().encode(err.message))
+  })

std/fs/testdata/empty_dir_sync.ts

@@ -0,0 +1,8 @@
+import { emptyDirSync } from "../empty_dir.ts";
+
+try {
+  emptyDirSync(Deno.args[1])
+  Deno.stdout.write(new TextEncoder().encode("success"))
+} catch (err) {
+  Deno.stdout.write(new TextEncoder().encode(err.message))
+}