diff --git a/test/amount-test.js b/test/amount-test.js
index 3c96f96c..c584a157 100644
--- a/test/amount-test.js
+++ b/test/amount-test.js
@@ -12,11 +12,26 @@ describe('Amount', function() {
       assert.strictEqual(Amount.from_human('0').add(Amount.from_human('-1')).to_human(), '-1');
     });
   });
+  describe('Positives', function() {
+    it('Number 1', function() {
+      assert(Amount.from_json('1').is_positive());
+    });
+  });
   describe('from_number', function() {
     it('Number 1', function() {
       assert.strictEqual(Amount.from_number(1).to_text_full(), '1/1/rrrrrrrrrrrrrrrrrrrrBZbvji');
     });
   });
+  describe('text_full_rewrite', function() {
+    it('Number 1', function() {
+      assert.strictEqual('0.000001/XRP', Amount.text_full_rewrite(1));
+    });
+  });
+  describe('json_rewrite', function() {
+    it('Number 1', function() {
+      assert.strictEqual('1', Amount.json_rewrite(1));
+    });
+  });
   describe('UInt160', function() {
     it('Parse 0', function () {
       assert.deepEqual(jsbn.nbi(), UInt160.from_generic('0')._value);
@@ -59,6 +74,12 @@ describe('Amount', function() {
     it('!is_valid "xx"', function() {
       assert(!Amount.is_valid('xx'));
     });
+    it('!is_valid_full 1', function() {
+      assert(!Amount.is_valid_full(1));
+    });
+    it('is_valid_full "1/USD/rNDKeo9RrCiRdfsMG8AdoZvNZxHASGzbZL"', function() {
+      assert(Amount.is_valid_full('1/USD/rNDKeo9RrCiRdfsMG8AdoZvNZxHASGzbZL'));
+    });
   });
   describe('Amount parsing', function() {
     it('Parse invalid string', function() {
@@ -131,6 +152,12 @@ describe('Amount', function() {
     it('Add USD to USD', function () {
       assert.strictEqual('200.52/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('150.02/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').add(Amount.from_json('50.5/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
     });
+    it('Add 0 USD to 1 USD', function() {
+      assert.strictEqual('1' , Amount.from_json('1/USD').add('0/USD').to_text());
+    });
+    it('Subtract USD from USD', function() {
+      assert.strictEqual('99.52/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('150.02/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').subtract(Amount.from_json('50.5/USD/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh')).to_text_full());
+    });
     it('Multiply 0 XRP with 0 XRP', function () {
       assert.strictEqual('0/XRP', Amount.from_json('0').multiply(Amount.from_json('0')).to_text_full());
     });
@@ -242,8 +269,39 @@ describe('Amount', function() {
     it('Divide EUR by XRP, neg, <1', function () {
       assert.strictEqual('-0.05/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh', Amount.from_json('-100/EUR/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh').divide(Amount.from_json('2000')).to_text_full());
     });
+    it('Divide by zero should throw', function() {
+      assert.throws(function() {
+        Amount.from_json(1).divide(Amount.from_json(0));
+      });
+    });
+    it('Divide zero by number', function() {
+      assert.strictEqual('0', Amount.from_json(0).divide(Amount.from_json(1)).to_text());
+    });
+    it('Divide invalid by number', function() {
+      assert.throws(function() {
+        Amount.from_json('x').divide(Amount.from_json('1'));
+      });
+    });
+    it('Divide number by invalid', function() {
+      assert.throws(function() {
+        Amount.from_json('1').divide(Amount.from_json('x'));
+      });
+    });
+    it('amount.abs -1 == 1', function() {
+      assert.strictEqual('1', Amount.from_json(-1).abs().to_text());
+    });
+    it('amount.copyTo native', function() {
+      assert(isNaN(Amount.from_json('x').copyTo(new Amount())._value));
+    });
+    it('amount.copyTo zero', function() {
+      assert(!(Amount.from_json(0).copyTo(new Amount())._is_negative))
+    });
   });
   describe('Amount comparisons', function() {
+    it('0 USD == 0 USD amount.equals string argument', function() {
+      var a = '0/USD/rNDKeo9RrCiRdfsMG8AdoZvNZxHASGzbZL';
+      assert(Amount.from_json(a).equals(a));
+    });
     it('0 USD == 0 USD', function () {
       var a = Amount.from_json('0/USD/rNDKeo9RrCiRdfsMG8AdoZvNZxHASGzbZL');
       var b = Amount.from_json('0/USD/rNDKeo9RrCiRdfsMG8AdoZvNZxHASGzbZL');
diff --git a/test/serializedtypes-test.js b/test/serializedtypes-test.js
index 18388b93..5ac5f31a 100644
--- a/test/serializedtypes-test.js
+++ b/test/serializedtypes-test.js
@@ -7,10 +7,6 @@ var BigInteger       = jsbn.BigInteger;
 
 var config = require('./testutils').get_config();
 
-
-
-
-
 describe('Serialized types', function() {
   describe('Int8', function() {
     it('Serialize 0', function () {
diff --git a/test/sign-test.js b/test/sign-test.js
index 695132ee..ec94c802 100644
--- a/test/sign-test.js
+++ b/test/sign-test.js
@@ -2,6 +2,10 @@ var assert = require('assert');
 var utils  = require('./testutils');
 var Seed   = utils.load_module('seed').Seed;
 
+function _isNaN(n) {
+  return typeof n === 'number' && isNaN(n);
+}
+
 describe('Signing', function() {
   describe('Keys', function() {
     it('SigningPubKey 1 (ripple-client issue #245)',  function () {
@@ -17,6 +21,36 @@ describe('Signing', function() {
       assert.strictEqual(pub, '0330E7FC9D56BB25D6893BA3F317AE5BCF33B3291BD63DB32654A313222F7FD020');
     });
   });
+  describe('parse_json', function() {
+    it('empty string', function() {
+      assert(_isNaN(new Seed().parse_json('').to_json()));
+    });
+    it('hex string', function() {
+      var str = new Array(33).join('0');
+      assert(_isNaN(new Seed().parse_json(str).to_json()));
+    });
+    it('passphrase', function() {
+      var str = new Array(60).join('0');
+      assert.strictEqual('snFRPnVL3secohdpwSie8ANXdFQvG', new Seed().parse_json(str).to_json());
+    });
+    it('null', function() {
+      assert(_isNaN(new Seed().parse_json(null).to_json()));
+    });
+  });
+  describe('parse_passphrase', function() {
+    it('invalid passphrase', function() {
+      assert.throws(function() {
+        new Seed().parse_passphrase(null);
+      });
+    });
+  });
+  describe('get_key', function() {
+    it('get key from invalid seed', function() {
+      assert.throws(function() {
+        new Seed().get_key('rBZ4j6MsoctipM6GEyHSjQKzXG3yambDnZ');
+      });
+    });
+  });
 });
 
 // vim:sw=2:sts=2:ts=8:et