Add some more unit tests

spec/term_spec.lua

@@ -0,0 +1,245 @@
+expose("module", function()
+   require("kiwi")
+end)
+
+describe("Term", function()
+   local kiwi = require("kiwi")
+   local LUA_VERSION = tonumber(_VERSION:match("%d+%.%d+"))
+
+   it("construction", function()
+      local v = kiwi.Var("foo")
+      local t = kiwi.Term(v)
+      assert.equal(v, t.var)
+      assert.equal(1.0, t.coefficient)
+
+      t = kiwi.Term(v, 100)
+      assert.equal(v, t.var)
+      assert.equal(100, t.coefficient)
+
+      if LUA_VERSION <= 5.2 then
+         assert.equal("100 foo", tostring(t))
+      else
+         assert.equal("100.0 foo", tostring(t))
+      end
+
+      assert.error(function()
+         kiwi.Term("")
+      end)
+   end)
+
+   describe("method", function()
+      local v, v2, t, t2
+
+      before_each(function()
+         v = kiwi.Var("foo")
+         t = kiwi.Term(v, 10)
+      end)
+
+      it("has value", function()
+         v:set(42)
+         assert.equal(420, t:value())
+         v:set(87)
+         assert.equal(870, t:value())
+      end)
+
+      it("has toexpr", function()
+         local e = t:toexpr()
+         assert.True(kiwi.is_expression(e))
+         assert.equal(0, e.constant)
+         local terms = e:terms()
+         assert.equal(1, #terms)
+         assert.equal(v, terms[1].var)
+         assert.equal(10.0, terms[1].coefficient)
+      end)
+
+      it("neg", function()
+         local neg = -t --[[@as kiwi.Term]]
+         assert.True(kiwi.is_term(neg))
+         assert.equal(v, neg.var)
+         assert.equal(-10, neg.coefficient)
+      end)
+
+      describe("bin op", function()
+         before_each(function()
+            v2 = kiwi.Var("bar")
+            t2 = kiwi.Term(v2)
+         end)
+
+         it("mul", function()
+            for _, prod in ipairs({ t * 2.0, 2 * t }) do
+               assert.True(kiwi.is_term(prod))
+               assert.equal(v, prod.var)
+               assert.equal(20, prod.coefficient)
+            end
+
+            assert.error(function()
+               local _ = t * v
+            end)
+         end)
+
+         it("div", function()
+            local quot = t / 2.0
+            assert.True(kiwi.is_term(quot))
+            assert.equal(v, quot.var)
+            assert.equal(5.0, quot.coefficient)
+
+            assert.error(function()
+               local _ = v / v2
+            end)
+         end)
+
+         it("add", function()
+            for _, sum in ipairs({ t + 2.0, 2 + t }) do
+               assert.True(kiwi.is_expression(sum))
+               assert.equal(2.0, sum.constant)
+
+               local terms = sum:terms()
+               assert.equal(1, #terms)
+               assert.equal(10.0, terms[1].coefficient)
+               assert.equal(v, terms[1].var)
+            end
+
+            local sum = t + v2
+            assert.True(kiwi.is_expression(sum))
+            assert.equal(0, sum.constant)
+            local terms = sum:terms()
+            assert.equal(2, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(1.0, terms[2].coefficient)
+
+            sum = t + t2
+            assert.True(kiwi.is_expression(sum))
+            assert.equal(0, sum.constant)
+            terms = sum:terms()
+            assert.equal(2, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(1.0, terms[2].coefficient)
+
+            local t3 = kiwi.Term(v2, 20)
+            sum = t3 + sum
+            assert.True(kiwi.is_expression(sum))
+            assert.equal(0, sum.constant)
+            terms = sum:terms()
+            assert.equal(3, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(1.0, terms[2].coefficient)
+            assert.equal(v2, terms[3].var)
+            assert.equal(20.0, terms[3].coefficient)
+
+            assert.error(function()
+               local _ = t + "foo"
+            end)
+            assert.error(function()
+               local _ = t + {}
+            end)
+         end)
+
+         it("sub", function()
+            local constants = { -2, 2 }
+            for i, diff in ipairs({ t - 2.0, 2 - t }) do
+               local constant = constants[i]
+               assert.True(kiwi.is_expression(diff))
+               assert.equal(constant, diff.constant)
+
+               local terms = diff:terms()
+               assert.equal(1, #terms)
+               assert.equal(v, terms[1].var)
+               assert.equal(constant < 0 and 10.0 or -10.0, terms[1].coefficient)
+            end
+
+            local diff = t - v2
+            assert.True(kiwi.is_expression(diff))
+            assert.equal(0, diff.constant)
+            local terms = diff:terms()
+            assert.equal(2, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(-1.0, terms[2].coefficient)
+
+            diff = t - t2
+            assert.True(kiwi.is_expression(diff))
+            assert.equal(0, diff.constant)
+            terms = diff:terms()
+            assert.equal(2, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(-1.0, terms[2].coefficient)
+
+            local t3 = kiwi.Term(v2, 20)
+            diff = t3 - diff
+            assert.True(kiwi.is_expression(diff))
+            assert.equal(0, diff.constant)
+            terms = diff:terms()
+            assert.equal(3, #terms)
+            assert.equal(v, terms[1].var)
+            assert.equal(-10.0, terms[1].coefficient)
+            assert.equal(v2, terms[2].var)
+            assert.equal(1.0, terms[2].coefficient)
+            assert.equal(v2, terms[3].var)
+            assert.equal(20.0, terms[3].coefficient)
+
+            assert.error(function()
+               local _ = t - "foo"
+            end)
+            assert.error(function()
+               local _ = t - {}
+            end)
+         end)
+
+         it("constraint term op expr", function()
+            local ops = { "LE", "EQ", "GE" }
+            for i, meth in ipairs({ "le", "eq", "ge" }) do
+               local c = t[meth](t, v2 + 1)
+               assert.True(kiwi.is_constraint(c))
+
+               local e = c:expression()
+               local terms = e:terms()
+               assert.equal(2, #terms)
+
+               -- order can be randomized due to use of map
+               if terms[1].var ~= v then
+                  terms[1], terms[2] = terms[2], terms[1]
+               end
+               assert.equal(v, terms[1].var)
+               assert.equal(10.0, terms[1].coefficient)
+               assert.equal(v2, terms[2].var)
+               assert.equal(-1.0, terms[2].coefficient)
+
+               assert.equal(-1, e.constant)
+               assert.equal(ops[i], c:op())
+               assert.equal(kiwi.strength.REQUIRED, c:strength())
+            end
+         end)
+
+         it("constraint term op term", function()
+            for i, meth in ipairs({ "le", "eq", "ge" }) do
+               local c = t[meth](t, t2)
+               assert.True(kiwi.is_constraint(c))
+
+               local e = c:expression()
+               local terms = e:terms()
+               assert.equal(2, #terms)
+
+               -- order can be randomized due to use of map
+               if terms[1].var ~= v then
+                  terms[1], terms[2] = terms[2], terms[1]
+               end
+               assert.equal(v, terms[1].var)
+               assert.equal(10.0, terms[1].coefficient)
+               assert.equal(v2, terms[2].var)
+               assert.equal(-1.0, terms[2].coefficient)
+
+               assert.equal(0, e.constant)
+            end
+         end)
+      end)
+   end)
+end)