1 files changed, 145 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testErrorInterceptor.cpp b/js/src/jsapi-tests/testErrorInterceptor.cpp
new file mode 100644
index 0000000000..031fa85afa
--- /dev/null
+++ b/js/src/jsapi-tests/testErrorInterceptor.cpp
@@ -0,0 +1,145 @@
+#include <iterator>
+
+#include "js/ErrorInterceptor.h"
+#include "jsapi-tests/tests.h"
+#include "util/StringBuffer.h"
+
+// Tests for JS_GetErrorInterceptorCallback and JS_SetErrorInterceptorCallback.
+
+namespace {
+static JS::PersistentRootedString gLatestMessage;
+
+// An interceptor that stores the error in `gLatestMessage`.
+struct SimpleInterceptor : JSErrorInterceptor {
+  virtual void interceptError(JSContext* cx, JS::HandleValue val) override {
+    js::JSStringBuilder buffer(cx);
+    if (!ValueToStringBuffer(cx, val, buffer)) {
+      MOZ_CRASH("Could not convert to string buffer");
+    }
+    gLatestMessage = buffer.finishString();
+    if (!gLatestMessage) {
+      MOZ_CRASH("Could not convert to string");
+    }
+  }
+};
+
+bool equalStrings(JSContext* cx, JSString* a, JSString* b) {
+  int32_t result = 0;
+  if (!JS_CompareStrings(cx, a, b, &result)) {
+    MOZ_CRASH("Could not compare strings");
+  }
+  return result == 0;
+}
+}  // namespace
+
+BEGIN_TEST(testErrorInterceptor) {
+  // Run the following snippets.
+  const char* SAMPLES[] = {
+      "throw new Error('I am an Error')\0",
+      "throw new TypeError('I am a TypeError')\0",
+      "throw new ReferenceError('I am a ReferenceError')\0",
+      "throw new SyntaxError('I am a SyntaxError')\0",
+      "throw 5\0",
+      "foo[0]\0",
+      "b[\0",
+  };
+  // With the simpleInterceptor, we should end up with the following error:
+  const char* TO_STRING[] = {
+      "Error: I am an Error\0",
+      "TypeError: I am a TypeError\0",
+      "ReferenceError: I am a ReferenceError\0",
+      "SyntaxError: I am a SyntaxError\0",
+      "5\0",
+      "ReferenceError: foo is not defined\0",
+      "SyntaxError: expected expression, got end of script\0",
+  };
+  static_assert(std::size(SAMPLES) == std::size(TO_STRING));
+
+  // Save original callback.
+  JSErrorInterceptor* original = JS_GetErrorInterceptorCallback(cx->runtime());
+  gLatestMessage.init(cx);
+
+  // Test without callback.
+  JS_SetErrorInterceptorCallback(cx->runtime(), nullptr);
+  CHECK(gLatestMessage == nullptr);
+
+  for (auto sample : SAMPLES) {
+    if (execDontReport(sample, __FILE__, __LINE__)) {
+      MOZ_CRASH("This sample should have failed");
+    }
+    CHECK(JS_IsExceptionPending(cx));
+    CHECK(gLatestMessage == nullptr);
+    JS_ClearPendingException(cx);
+  }
+
+  // Test with callback.
+  SimpleInterceptor simpleInterceptor;
+  JS_SetErrorInterceptorCallback(cx->runtime(), &simpleInterceptor);
+
+  // Test that we return the right callback.
+  CHECK_EQUAL(JS_GetErrorInterceptorCallback(cx->runtime()),
+              &simpleInterceptor);
+
+  // This shouldn't cause any error.
+  EXEC("function bar() {}");
+  CHECK(gLatestMessage == nullptr);
+
+  // Test error throwing with a callback that succeeds.
+  for (size_t i = 0; i < std::size(SAMPLES); ++i) {
+    // This should cause the appropriate error.
+    if (execDontReport(SAMPLES[i], __FILE__, __LINE__)) {
+      MOZ_CRASH("This sample should have failed");
+    }
+    CHECK(JS_IsExceptionPending(cx));
+
+    // Check result of callback.
+    CHECK(gLatestMessage != nullptr);
+    CHECK(js::StringEqualsAscii(&gLatestMessage->asLinear(), TO_STRING[i]));
+
+    // Check the final error.
+    JS::RootedValue exn(cx);
+    CHECK(JS_GetPendingException(cx, &exn));
+    JS_ClearPendingException(cx);
+
+    js::JSStringBuilder buffer(cx);
+    CHECK(ValueToStringBuffer(cx, exn, buffer));
+    JS::Rooted<JSLinearString*> linear(cx, buffer.finishString());
+    CHECK(equalStrings(cx, linear, gLatestMessage));
+
+    // Cleanup.
+    gLatestMessage = nullptr;
+  }
+
+  // Test again without callback.
+  JS_SetErrorInterceptorCallback(cx->runtime(), nullptr);
+  for (size_t i = 0; i < std::size(SAMPLES); ++i) {
+    if (execDontReport(SAMPLES[i], __FILE__, __LINE__)) {
+      MOZ_CRASH("This sample should have failed");
+    }
+    CHECK(JS_IsExceptionPending(cx));
+
+    // Check that the callback wasn't called.
+    CHECK(gLatestMessage == nullptr);
+
+    // Check the final error.
+    JS::RootedValue exn(cx);
+    CHECK(JS_GetPendingException(cx, &exn));
+    JS_ClearPendingException(cx);
+
+    js::JSStringBuilder buffer(cx);
+    CHECK(ValueToStringBuffer(cx, exn, buffer));
+    JS::Rooted<JSLinearString*> linear(cx, buffer.finishString());
+    CHECK(js::StringEqualsAscii(linear, TO_STRING[i]));
+
+    // Cleanup.
+    gLatestMessage = nullptr;
+  }
+
+  // Cleanup
+  JS_SetErrorInterceptorCallback(cx->runtime(), original);
+  gLatestMessage = nullptr;
+  JS_ClearPendingException(cx);
+
+  return true;
+}
+END_TEST(testErrorInterceptor)