1 files changed, 108 insertions, 0 deletions
diff --git a/spec/05-bitflags_spec.lua b/spec/05-bitflags_spec.lua
new file mode 100644
index 0000000..01bf958
--- /dev/null
+++ b/spec/05-bitflags_spec.lua
@@ -0,0 +1,108 @@
+describe("BitFlags library", function()
+
+  local sys = require("system")
+
+  it("creates new flag objects", function()
+    local bf = sys.bitflag(255)
+    assert.is_not_nil(bf)
+    assert.are.equal(255, bf:value())
+    assert.is.userdata(bf)
+  end)
+
+  it("converts to a hex string", function()
+    local bf = sys.bitflag(255)
+    assert.are.equal("bitflags: 255", tostring(bf))
+  end)
+
+  it("handles OR/ADD operations", function()
+    -- one at a time
+    local bf1 = sys.bitflag(1)    -- b0001
+    local bf2 = sys.bitflag(2)    -- b0010
+    local bf3 = bf1 + bf2         -- b0011
+    assert.are.equal(3, bf3:value())
+    -- multiple at once
+    local bf4 = sys.bitflag(4+8)  -- b1100
+    local bf5 = bf3 + bf4         -- b1111
+    assert.are.equal(15, bf5:value())
+    -- multiple that were already set
+    local bf6 = sys.bitflag(15)   -- b1111
+    local bf7 = sys.bitflag(8+2)  -- b1010
+    local bf8 = bf6 + bf7         -- b1111
+    assert.are.equal(15, bf8:value())
+  end)
+
+  it("handles AND-NOT/SUBSTRACT operations", function()
+    -- one at a time
+    local bf1 = sys.bitflag(3)    -- b0011
+    local bf2 = sys.bitflag(1)    -- b0001
+    local bf3 = bf1 - bf2         -- b0010
+    assert.are.equal(2, bf3:value())
+    -- multiple at once
+    local bf4 = sys.bitflag(15)   -- b1111
+    local bf5 = sys.bitflag(8+2)  -- b1010
+    local bf6 = bf4 - bf5         -- b0101
+    assert.are.equal(5, bf6:value())
+    -- multiple that were not set
+    local bf7 = sys.bitflag(3)    -- b0011
+    local bf8 = sys.bitflag(15)   -- b1111
+    local bf9 = bf7 - bf8         -- b0000
+    assert.are.equal(0, bf9:value())
+  end)
+
+  it("checks for equality", function()
+    local bf1 = sys.bitflag(4)
+    local bf2 = sys.bitflag(4)
+    local bf3 = sys.bitflag(5)
+    assert.is.True(bf1 == bf2)
+    assert.is.False(bf1 == bf3)
+  end)
+
+  it("indexes bits correctly", function()
+    local bf = sys.bitflag(4)   -- b100
+    assert.is_true(bf[2])
+    assert.is_false(bf[1])
+  end)
+
+  it("errors on reading invalid bit indexes", function()
+    local bf = sys.bitflag(4)
+    assert.has_error(function() return bf[-10] end, "index out of range")
+    assert.has_error(function() return bf[10000] end, "index out of range")
+    assert.has_no_error(function() return bf.not_a_number end)
+  end)
+
+  it("sets and clears bits correctly", function()
+    local bf = sys.bitflag(0)
+    bf[1] = true
+    assert.is_true(bf[1])
+    bf[1] = false
+    assert.is_false(bf[1])
+  end)
+
+  it("errors on setting invalid bit indexes", function()
+    local bf = sys.bitflag(0)
+    assert.has_error(function() bf[-10] = true end, "index out of range")
+    assert.has_error(function() bf[10000] = true end, "index out of range")
+    assert.has_error(function() bf.not_a_number = true end, "index must be a number")
+  end)
+
+  it("handles <= and >= operations", function()
+    local bf1 = sys.bitflag(3)    -- b0011
+    local bf2 = sys.bitflag(15)   -- b1111
+    assert.is_true(bf2 >= bf1)    -- all bits in bf1 are set in bf2
+    assert.is_true(bf2 > bf1)     -- all bits in bf1 are set in bf2 and some more
+    assert.is_false(bf2 <= bf1)   -- not all bits in bf2 are set in bf1
+    assert.is_false(bf2 < bf1)    -- not all bits in bf2 are set in bf1
+  end)
+
+  it("checks for a subset using 'has'", function()
+    local bf1 = sys.bitflag(3)    -- b0011
+    local bf2 = sys.bitflag(3)    -- b0011
+    local bf3 = sys.bitflag(15)   -- b1111
+    local bf0 = sys.bitflag(0)    -- b0000
+    assert.is_true(bf1:has(bf2))  -- equal
+    assert.is_true(bf3:has(bf1))  -- is a subset, and has more flags
+    assert.is_false(bf1:has(bf3)) -- not a subset, bf3 has more flags
+    assert.is_false(bf1:has(bf0)) -- bf0 is unset, always returns false
+  end)
+
+end)