diff -r 000000000000 -r 6474c204b198 testing/mochitest/tests/browser/browser_getTestFile.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/mochitest/tests/browser/browser_getTestFile.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,44 @@
+function test() {
+  let {Promise} = Components.utils.import("resource://gre/modules/Promise.jsm");
+  Components.utils.import("resource://gre/modules/osfile.jsm");
+  let decoder = new TextDecoder();
+
+  waitForExplicitFinish();
+
+  SimpleTest.doesThrow(function () {
+    getTestFilePath("/browser_getTestFile.js")
+  }, "getTestFilePath rejects absolute paths");
+
+  Promise.all([
+    OS.File.exists(getTestFilePath("browser_getTestFile.js"))
+      .then(function (exists) {
+        ok(exists, "getTestFilePath consider the path as being relative");
+      }),
+
+    OS.File.exists(getTestFilePath("./browser_getTestFile.js"))
+      .then(function (exists) {
+        ok(exists, "getTestFilePath also accepts explicit relative path");
+      }),
+
+    OS.File.exists(getTestFilePath("./browser_getTestFileTypo.xul"))
+      .then(function (exists) {
+        ok(!exists, "getTestFilePath do not throw if the file doesn't exists");
+      }),
+
+    OS.File.read(getTestFilePath("test-dir/test-file"))
+      .then(function (array) {
+        is(decoder.decode(array), "foo\n", "getTestFilePath can reach sub-folder files 1/2");
+      }),
+
+    OS.File.read(getTestFilePath("./test-dir/test-file"))
+      .then(function (array) {
+        is(decoder.decode(array), "foo\n", "getTestFilePath can reach sub-folder files 2/2");
+      })
+
+  ]).then(function () {
+    finish();
+  }, function (error) {
+    ok(false, error);
+    finish();
+  });
+}