1 files changed, 42 insertions, 0 deletions
diff --git a/netwerk/test/unit/test_safeoutputstream_append.js b/netwerk/test/unit/test_safeoutputstream_append.js
new file mode 100644
index 000000000..a7abb06e6
--- /dev/null
+++ b/netwerk/test/unit/test_safeoutputstream_append.js
@@ -0,0 +1,42 @@
+/* atomic-file-output-stream and safe-file-output-stream should throw and
+ * exception if PR_APPEND is explicity specified without PR_TRUNCATE. */
+
+const PR_WRONLY      = 0x02;
+const PR_CREATE_FILE = 0x08;
+const PR_APPEND      = 0x10;
+const PR_TRUNCATE    = 0x20;
+
+const { Services } = Cu.import("resource://gre/modules/Services.jsm", {});
+
+function check_flag(file, contractID, flags, throws) {
+  let stream = Cc[contractID].createInstance(Ci.nsIFileOutputStream);
+
+  if (throws) {
+    /* NS_ERROR_INVALID_ARG is reported as NS_ERROR_ILLEGAL_VALUE, since they
+     * are same value. */
+    Assert.throws(() => stream.init(file, flags, 0o644, 0),
+                  /NS_ERROR_ILLEGAL_VALUE/);
+  } else {
+    stream.init(file, flags, 0o644, 0);
+    stream.close();
+  }
+}
+
+function run_test() {
+  let filename = "test.txt";
+  let file = Services.dirsvc.get("TmpD", Ci.nsIFile);
+  file.append(filename);
+
+  let tests = [
+    [PR_WRONLY | PR_CREATE_FILE | PR_APPEND | PR_TRUNCATE, false],
+    [PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE, false],
+    [PR_WRONLY | PR_CREATE_FILE | PR_APPEND, true],
+    [-1, false],
+  ];
+  for (let contractID of ["@mozilla.org/network/atomic-file-output-stream;1",
+                          "@mozilla.org/network/safe-file-output-stream;1"]) {
+    for (let [flags, throws] of tests) {
+      check_flag(file, contractID, flags, throws);
+    }
+  }
+}