import core.stdc.stdio : fprintf, printf, stderr;

void test(string comp = "==", A, B)(A a, B b, string msg, size_t line = __LINE__)
{
    int ret = () {
        import core.exception : AssertError;
        try
        {
            assert(mixin("a " ~ comp ~ " b"));
        } catch(AssertError e)
        {
            // don't use assert here for better debugging
            if (e.msg != msg)
            {
                printf("Line %d: '%.*s' != '%.*s'\n", line, e.msg.length, e.msg.ptr, msg.length, msg.ptr);
                return 1;
            }
            return 0;
        }
        printf("Line %d: No assert triggered\n", line);
        return 1;
    }();
    // don't use assert here for better debugging
    if (ret != 0) {
        import core.stdc.stdlib : exit;
        exit(1);
    }
}

void testIntegers()()
{
    test(1, 2, "1 != 2");
    test(-10, 8, "-10 != 8");
    test(byte.min, byte.max, "-128 != 127");
    test(ubyte.min, ubyte.max, "0 != 255");
    test(short.min, short.max, "-32768 != 32767");
    test(ushort.min, ushort.max, "0 != 65535");
    test(int.min, int.max, "-2147483648 != 2147483647");
    test(uint.min, uint.max, "0 != 4294967295");
    test(long.min, long.max, "-9223372036854775808 != 9223372036854775807");
    test(ulong.min, ulong.max, "0 != 18446744073709551615");

    int testFun() { return 1; }
    test(testFun(), 2, "1 != 2");
}

void testIntegerComparisons()()
{
    test!"!="(2, 2, "2 == 2");
    test!"<"(2, 1, "2 >= 1");
    test!"<="(2, 1, "2 > 1");
    test!">"(1, 2, "1 <= 2");
    test!">="(1, 2, "1 < 2");
}

void testFloatingPoint()()
{
    test(1.5, 2.5, "1.5 != 2.5");
    test(float.max, -float.max, "3.40282e+38 != -3.40282e+38");
    test(double.max, -double.max, "1.79769e+308 != -1.79769e+308");
}

void testStrings()
{
    test("foo", "bar", `"foo" != "bar"`);
    test("", "bar", `"" != "bar"`);

    char[] dlang = "dlang".dup;
    const(char)[] rust = "rust";
    test(dlang, rust, `"dlang" != "rust"`);
}

void testToString()()
{
    class Foo
    {
        this(string payload) {
            this.payload = payload;
        }

        string payload;
        override string toString() {
            return "Foo(" ~ payload ~ ")";
        }
    }
    test(new Foo("a"), new Foo("b"), "Foo(a) != Foo(b)");
}


void testArray()()
{
    test([1], [0], "[1] != [0]");
    test([1, 2, 3], [0], "[1, 2, 3] != [0]");

    // test with long arrays
    int[] arr;
    foreach (i; 0 .. 100)
        arr ~= i;
    test(arr, [0], "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, ...] != [0]");
}

void testStruct()()
{
    struct S { int s; }
    test(S(0), S(1), "S(0) !is S(1)");
}

void testAA()()
{
    test([1:"one"], [2: "two"], `[1: "one"] != [2: "two"]`);
}

void main()
{
    testIntegers();
    testIntegerComparisons();
    testFloatingPoint();
    testStrings();
    testToString();
    testArray();
    testStruct();
    testAA();
    fprintf(stderr, "success.\n");
}
