#include "jsapi.h"

#include "jsapi-tests/tests.h"

#include "vm/StringBuffer.h"

// Tests for JS_GetErrorInterceptorCallback and JS_SetErrorInterceptorCallback.


namespace {
const double EXN_VALUE = 3.14;

static JS::PersistentRootedString gLatestMessage;

// An interceptor that stores the error in `gLatestMessage`.
struct SimpleInterceptor: JSErrorInterceptor {
    virtual void interceptError(JSContext* cx, const JS::Value& val) override {
        js::StringBuffer 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;
}
}

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",
        "undefined[0]\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",
        "TypeError: undefined has no properties\0",
        "ReferenceError: foo is not defined\0",
        "SyntaxError: expected expression, got end of script\0",
    };
    MOZ_ASSERT(mozilla::ArrayLength(SAMPLES) == mozilla::ArrayLength(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 < mozilla::ArrayLength(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::StringBuffer buffer(cx);
        CHECK(ValueToStringBuffer(cx, exn, buffer));
        CHECK(equalStrings(cx, buffer.finishString(), gLatestMessage));

        // Cleanup.
        gLatestMessage = nullptr;
    }

    // Test again without callback.
    JS_SetErrorInterceptorCallback(cx->runtime(), nullptr);
    for (size_t i = 0; i < mozilla::ArrayLength(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::StringBuffer buffer(cx);
        CHECK(ValueToStringBuffer(cx, exn, buffer));
        CHECK(js::StringEqualsAscii(buffer.finishString(), TO_STRING[i]));

        // Cleanup.
        gLatestMessage = nullptr;
    }

    // Cleanup
    JS_SetErrorInterceptorCallback(cx->runtime(), original);
    gLatestMessage = nullptr;
    JS_ClearPendingException(cx);

    return true;
}
END_TEST(testErrorInterceptor)