Add EnumFlags tests

src/EnumFlags.zig

@@ -8,7 +8,13 @@ pub fn EnumFlags(comptime E: type) type {
 
         mask: BackingInt,
 
-        pub const empty: Self = .{ .data = 0 };
+        pub const empty: Self = .{ .mask = 0 };
+
+        test empty {
+            const flags: EnumFlags(Enum) = .empty;
+
+            try std.testing.expectEqual(0b0000_0000, flags.mask);
+        }
 
         pub fn from(mask: BackingInt) Self {
             return .{
@@ -16,6 +22,12 @@ pub fn EnumFlags(comptime E: type) type {
             };
         }
 
+        test from {
+            const flags: EnumFlags(Enum) = .from(0b0000_0001);
+
+            try std.testing.expectEqual(0b0000_0001, flags.mask);
+        }
+
         pub fn contains(self: Self, flag: E) bool {
             return (self.mask & @intFromEnum(flag)) != 0;
         }
@@ -48,3 +60,64 @@ pub fn EnumFlags(comptime E: type) type {
     };
 }
 
+const Enum = enum(u8) {
+    a = 0b0000_0001,
+    b = 0b0000_0010,
+    c = 0b0000_0100,
+};
+
+test {
+
+    std.testing.refAllDecls(EnumFlags(Enum));
+}
+
+test "EnumFlags operations" {
+    var flags: EnumFlags(Enum) = .from(0b0000_0001);
+
+    try std.testing.expect(flags.contains(Enum.a));
+
+    flags.remove(Enum.a);
+    try std.testing.expect(!flags.contains(Enum.a));
+
+    flags.remove(Enum.a); // Removing twice should not enable the flag
+    try std.testing.expect(!flags.contains(Enum.a));
+
+    flags.insert(Enum.b);
+    try std.testing.expectEqual(0b0000_0010, flags.mask);
+    try std.testing.expect(flags.contains(Enum.b));
+    try std.testing.expect(!flags.contains(Enum.a));
+
+    flags.toggle(Enum.a);
+    try std.testing.expectEqual(0b0000_0011, flags.mask);
+    try std.testing.expect(flags.contains(Enum.a));
+    try std.testing.expect(flags.contains(Enum.b));
+    try std.testing.expect(!flags.contains(Enum.c));
+}
+
+fn testFormat(expected: []const u8, flags: EnumFlags(Enum)) !void {
+    var out_buf: [1024]u8 = undefined;
+    var out: std.Io.Writer = .fixed(&out_buf);
+
+    try flags.format(&out);
+
+    try std.testing.expectEqualStrings(expected, out.buffered());
+}
+
+test "EnumFlags format" {
+    var flags: EnumFlags(Enum) = .empty;
+
+    flags.toggle(Enum.a);
+    flags.toggle(Enum.b);
+    flags.toggle(Enum.c);
+    try testFormat("a | b | c", flags);
+
+    flags.toggle(Enum.b);
+    try testFormat("a | c", flags);
+
+    flags.remove(Enum.c);
+    try testFormat("a", flags);
+
+    flags.insert(Enum.b);
+    try testFormat("a | b", flags);
+}
+