added deserialiser tests, fixed some bugs in deserialised

tests/deserialise/string.zig

@@ -0,0 +1,84 @@
+const std = @import("std");
+
+const msgpack = @import("msgpack");
+
+const deserialise = msgpack.deserialise.deserialise;
+
+fn test_string(bytes: []const u8, expected: []const u8) !void {
+    const alloc = std.testing.allocator;
+
+    const obj = try deserialise(alloc, bytes);
+    defer obj.deinit(alloc);
+
+    try std.testing.expectEqualStrings(expected, obj.raw.string);
+}
+
+test "string 1" {
+    const bytes = [_]u8{ 0b101_00000 | 0x03, 'A', 'B', 'C' };
+
+    try test_string(&bytes, "ABC");
+}
+
+test "string 2" {
+    const bytes = [_]u8{ 0xd9, 0x03, 'A', 'B', 'C' };
+
+    try test_string(&bytes, "ABC");
+}
+test "string 3" {
+    const bytes = [_]u8{ 0xd9, 0x00 };
+
+    try test_string(&bytes, "");
+}
+test "string 4" {
+    var bytes: [2 + 255]u8 = undefined;
+
+    bytes[0] = 0xd9;
+    bytes[1] = 0xff;
+
+    for (bytes[2..]) |*c| {
+        c.* = 'A';
+    }
+
+    try test_string(&bytes, "A" ** 255);
+}
+test "string 5" {
+    var bytes: [3 + 256]u8 = undefined;
+
+    bytes[0] = 0xda;
+    bytes[1] = 0x01;
+    bytes[2] = 0x00;
+
+    for (bytes[3..]) |*c| {
+        c.* = 'A';
+    }
+
+    try test_string(&bytes, "A" ** 256);
+}
+test "string 6" {
+    var bytes: [3 + 65535]u8 = undefined;
+
+    bytes[0] = 0xda;
+    bytes[1] = 0xff;
+    bytes[2] = 0xff;
+
+    for (bytes[3..]) |*c| {
+        c.* = 'A';
+    }
+
+    try test_string(&bytes, "A" ** 65535);
+}
+test "string 7" {
+    var bytes: [5 + 65536]u8 = undefined;
+
+    bytes[0] = 0xdb;
+    bytes[1] = 0x00;
+    bytes[2] = 0x01;
+    bytes[3] = 0x00;
+    bytes[4] = 0x00;
+
+    for (bytes[5..]) |*c| {
+        c.* = 'A';
+    }
+
+    try test_string(&bytes, "A" ** 65536);
+}