1 files changed, 157 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testEmptyWindowIsOmitted.cpp b/js/src/jsapi-tests/testEmptyWindowIsOmitted.cpp
new file mode 100644
index 0000000000..44b6331be5
--- /dev/null
+++ b/js/src/jsapi-tests/testEmptyWindowIsOmitted.cpp
@@ -0,0 +1,157 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/TextUtils.h"
+#include "mozilla/Utf8.h"
+
+#include <cstring>
+
+#include "jsfriendapi.h"
+
+#include "js/CharacterEncoding.h"
+#include "js/CompilationAndEvaluation.h"  // JS::Compile
+#include "js/Exception.h"
+#include "js/friend/ErrorMessages.h"  // JSMSG_*
+#include "js/SourceText.h"
+#include "jsapi-tests/tests.h"
+#include "util/Text.h"
+#include "vm/ErrorReporting.h"
+
+using mozilla::IsAsciiHexDigit;
+using mozilla::Utf8Unit;
+
+BEGIN_TEST(testEmptyWindow) { return testUtf8() && testUtf16(); }
+
+bool testUtf8() {
+  // Bad unit with nothing before it.
+  static const char badLeadingUnit[] = "\x80";
+  CHECK(testOmittedWindow(badLeadingUnit, JSMSG_BAD_LEADING_UTF8_UNIT, "0x80"));
+
+  // Bad unit at start of a fresh line.
+  static const char badStartingFreshLine[] = "var x = 5;\n\x98";
+  CHECK(testOmittedWindow(badStartingFreshLine, JSMSG_BAD_LEADING_UTF8_UNIT,
+                          "0x98"));
+
+  // Bad trailing unit in initial code point.
+  static const char badTrailingUnit[] = "\xD8\x20";
+  CHECK(testOmittedWindow(badTrailingUnit, JSMSG_BAD_TRAILING_UTF8_UNIT,
+                          "0xD8 0x20"));
+
+  // Bad trailing unit at start of a fresh line.
+  static const char badTrailingUnitFreshLine[] = "var x = 5;\n\xD8\x20";
+  CHECK(testOmittedWindow(badTrailingUnitFreshLine,
+                          JSMSG_BAD_TRAILING_UTF8_UNIT, "0xD8 0x20"));
+
+  // Overlong in initial code point.
+  static const char overlongInitial[] = "\xC0\x80";
+  CHECK(testOmittedWindow(overlongInitial, JSMSG_FORBIDDEN_UTF8_CODE_POINT,
+                          "0xC0 0x80"));
+
+  // Overlong at start of a fresh line.
+  static const char overlongFreshLine[] = "var x = 5;\n\xC0\x81";
+  CHECK(testOmittedWindow(overlongFreshLine, JSMSG_FORBIDDEN_UTF8_CODE_POINT,
+                          "0xC0 0x81"));
+
+  // Not-enough in initial code point.
+  static const char notEnoughInitial[] = "\xF0";
+  CHECK(
+      testOmittedWindow(notEnoughInitial, JSMSG_NOT_ENOUGH_CODE_UNITS, "0xF0"));
+
+  // Not-enough at start of a fresh line.
+  static const char notEnoughFreshLine[] = "var x = 5;\n\xF0";
+  CHECK(testOmittedWindow(notEnoughFreshLine, JSMSG_NOT_ENOUGH_CODE_UNITS,
+                          "0xF0"));
+
+  return true;
+}
+
+bool testUtf16() {
+  // Bad unit with nothing before it.
+  static const char16_t badLeadingUnit[] = u"\xDFFF";
+  CHECK(testOmittedWindow(badLeadingUnit, JSMSG_ILLEGAL_CHARACTER));
+
+  // Bad unit at start of a fresh line.
+  static const char16_t badStartingFreshLine[] = u"var x = 5;\n\xDFFF";
+  CHECK(testOmittedWindow(badStartingFreshLine, JSMSG_ILLEGAL_CHARACTER));
+
+  return true;
+}
+
+static bool startsWith(const char* str, const char* prefix) {
+  return std::strncmp(prefix, str, strlen(prefix)) == 0;
+}
+
+static bool equals(const char* str, const char* expected) {
+  return std::strcmp(str, expected) == 0;
+}
+
+JSScript* compile(const char16_t* chars, size_t len) {
+  JS::SourceText<char16_t> source;
+  MOZ_RELEASE_ASSERT(
+      source.init(cx, chars, len, JS::SourceOwnership::Borrowed));
+
+  JS::CompileOptions options(cx);
+  return JS::Compile(cx, options, source);
+}
+
+JSScript* compile(const char* chars, size_t len) {
+  JS::SourceText<Utf8Unit> source;
+  MOZ_RELEASE_ASSERT(
+      source.init(cx, chars, len, JS::SourceOwnership::Borrowed));
+
+  JS::CompileOptions options(cx);
+  return JS::Compile(cx, options, source);
+}
+
+template <typename CharT, size_t N>
+bool testOmittedWindow(const CharT (&chars)[N], unsigned expectedErrorNumber,
+                       const char* badCodeUnits = nullptr) {
+  JS::Rooted<JSScript*> script(cx, compile(chars, N - 1));
+  CHECK(!script);
+
+  JS::ExceptionStack exnStack(cx);
+  CHECK(JS::StealPendingExceptionStack(cx, &exnStack));
+
+  JS::ErrorReportBuilder report(cx);
+  CHECK(report.init(cx, exnStack, JS::ErrorReportBuilder::WithSideEffects));
+
+  const auto* errorReport = report.report();
+
+  CHECK(errorReport->errorNumber == expectedErrorNumber);
+
+  if (const auto& notes = errorReport->notes) {
+    CHECK(sizeof(CharT) == 1);
+    CHECK(badCodeUnits != nullptr);
+
+    auto iter = notes->begin();
+    CHECK(iter != notes->end());
+
+    const char* noteMessage = (*iter)->message().c_str();
+
+    // The prefix ought always be the same.
+    static constexpr char expectedPrefix[] =
+        "the code units comprising this invalid code point were: ";
+    constexpr size_t expectedPrefixLen = js_strlen(expectedPrefix);
+
+    CHECK(startsWith(noteMessage, expectedPrefix));
+
+    // The end of the prefix is the bad code units.
+    CHECK(equals(noteMessage + expectedPrefixLen, badCodeUnits));
+
+    ++iter;
+    CHECK(iter == notes->end());
+  } else {
+    CHECK(sizeof(CharT) == 2);
+
+    // UTF-16 encoding "errors" are not categorical errors, so the errors
+    // are just of the invalid-character sort, without an accompanying note
+    // spelling out a series of invalid code units.
+    CHECK(!badCodeUnits);
+  }
+
+  CHECK(!errorReport->linebuf());
+
+  return true;
+}
+END_TEST(testEmptyWindow)