From aad244be7a84965da49ee4061cfc8634dfe4064e Mon Sep 17 00:00:00 2001
From: David Greenspan <dgreenspan@alum.mit.edu>
Date: Wed, 24 Dec 2014 12:20:17 -0800
Subject: [PATCH] Finish xor tests

---
 packages/logic-solver/logic.js       | 17 ++++----
 packages/logic-solver/logic_tests.js | 65 +++++++++++++++++++++++++++-
 2 files changed, 72 insertions(+), 10 deletions(-)

diff --git a/packages/logic-solver/logic.js b/packages/logic-solver/logic.js
index 3988f89146..d51151be26 100644
--- a/packages/logic-solver/logic.js
+++ b/packages/logic-solver/logic.js
@@ -491,6 +491,13 @@ var group = function (array, N) {
 };
 
 Logic._defineFormula(Logic.XorFormula, 'xor', {
+  _grouped: function () {
+    return new Logic.XorFormula(
+      _.map(group(this.operands, 3), function (group) {
+        return (group.length === 1 ?
+                group[0] : new Logic.XorFormula(group));
+      }));
+  },
   _genTrue: function (makeClause) {
     var args = this.operands;
     var not = Logic.not;
@@ -509,10 +516,7 @@ Logic._defineFormula(Logic.XorFormula, 'xor', {
               makeClause(not(A), B, not(C)), // -A v B v -C
               makeClause(not(A), not(B), C)]; // -A v -B v C
     } else {
-      return (new Logic.XorFormula(
-        _.map(group(args, 3), function (group) {
-          return new Logic.XorFormula(group);
-        })))._genTrue(makeClause);
+      return this._grouped()._genTrue(makeClause);
     }
   },
   _genFalse: function (makeClause) {
@@ -533,10 +537,7 @@ Logic._defineFormula(Logic.XorFormula, 'xor', {
               makeClause(A, not(B), C), // A v -B v C
               makeClause(A, B, not(C))]; // A v B v -C
     } else {
-      return (new Logic.XorFormula(
-        _.map(group(args, 3), function (group) {
-          return new Logic.XorFormula(group);
-        })))._genFalse(makeClause);
+      return this._grouped()._genFalse(makeClause);
     }
   }
 });
diff --git a/packages/logic-solver/logic_tests.js b/packages/logic-solver/logic_tests.js
index 96d8516269..28c6f4c9ec 100644
--- a/packages/logic-solver/logic_tests.js
+++ b/packages/logic-solver/logic_tests.js
@@ -297,7 +297,68 @@ Tinytest.add("logic-solver - Logic.xor", function (test) {
     ["A v -B", "-A v B"],
     function (s) {
       s.require(Logic.xor(["A", []], ["B"], [])); },
-    ["A v B", "-A v -B"]
-    // XXX test 3 and 4 args
+    ["A v B", "-A v -B"],
+    function (s) {
+      s.require(Logic.xor("A", "B", "C")); },
+    ["A v B v C", "A v -B v -C", "-A v B v -C", "-A v -B v C"],
+    function (s) {
+      s.forbid(Logic.xor("A", "B", "C"));  },
+    ["-A v -B v -C", "-A v B v C", "A v -B v C", "A v B v -C"],
+    function (s) {
+      s.require(Logic.xor("A", "B", "C", "D")); },
+    ["A v B v C v -$xor1",
+     "A v -B v -C v -$xor1",
+     "-A v B v -C v -$xor1",
+     "-A v -B v C v -$xor1",
+     "$xor1 v D",
+     "-A v -B v -C v $xor1",
+     "-A v B v C v $xor1",
+     "A v -B v C v $xor1",
+     "A v B v -C v $xor1",
+     "-$xor1 v -D"],
+    function (s) {
+      s.forbid(Logic.xor("A", "B", "C", "D")); },
+    ["A v B v C v -$xor1",
+     "A v -B v -C v -$xor1",
+     "-A v B v -C v -$xor1",
+     "-A v -B v C v -$xor1",
+     "$xor1 v -D",
+     "-A v -B v -C v $xor1",
+     "-A v B v C v $xor1",
+     "A v -B v C v $xor1",
+     "A v B v -C v $xor1",
+     "-$xor1 v D"],
+    function (s) {
+      s.require(Logic.xor("A", "B", "C", "D", "E")); },
+    ["A v B v C v -$xor1",
+     "A v -B v -C v -$xor1",
+     "-A v B v -C v -$xor1",
+     "-A v -B v C v -$xor1",
+     "D v E v -$xor2",
+     "-D v -E v -$xor2",
+     "$xor1 v $xor2",
+     "-A v -B v -C v $xor1",
+     "-A v B v C v $xor1",
+     "A v -B v C v $xor1",
+     "A v B v -C v $xor1",
+     "D v -E v $xor2",
+     "-D v E v $xor2",
+     "-$xor1 v -$xor2"],
+    function (s) {
+      s.forbid(Logic.xor("A", "B", "C", "D", "E")); },
+    ["A v B v C v -$xor1",
+     "A v -B v -C v -$xor1",
+     "-A v B v -C v -$xor1",
+     "-A v -B v C v -$xor1",
+     "D v -E v $xor2",
+     "-D v E v $xor2",
+     "$xor1 v -$xor2",
+     "-A v -B v -C v $xor1",
+     "-A v B v C v $xor1",
+     "A v -B v C v $xor1",
+     "A v B v -C v $xor1",
+     "D v E v -$xor2",
+     "-D v -E v -$xor2",
+     "-$xor1 v $xor2"]
   ]);
 });