Full coverage (#2)

* Parser full coverage

* Syntax tree full coverage

homotopy/parser.py

@@ -2,9 +2,17 @@
 import ply.yacc as yacc
 from homotopy.syntax_tree import SimpleSnippet, CompositeSnippet
 
+# Exceptions
+
+
+class IllegalCharacter(Exception):
+    pass
+
 # Lexer
 
 # List of token names.
+
+
 tokens = (
     'SNIPPET',
     'LEFT_OPERATOR',
@@ -23,10 +31,11 @@
 
 # Error handling rule
 def t_error(t):
-    print("Illegal character '%s'" % t.value[0])
-    t.lexer.skip(1)
+    raise IllegalCharacter(t.value[0])
 
 # Build the lexer
+
+
 lexer = lex.lex()
 
 # Parser

test/testParser.py

@@ -1,13 +1,16 @@
 from unittest import TestCase
 
-from homotopy.parser import parser
+from homotopy.parser import parser, IllegalCharacter
 from homotopy.syntax_tree import SimpleSnippet, CompositeSnippet
 
 
 class TestParser(TestCase):
     def test_basic(self):
         self.assertEqual(parser.parse('asd'), SimpleSnippet('asd'))
 
+        with self.assertRaises(IllegalCharacter):
+            parser.parse("☼")
+
     def test_left_associativity(self):
         left = '!@#'
         for l in left:

test/testSyntax_tree.py

@@ -4,13 +4,15 @@
 
 
 class TestSyntaxTree(TestCase):
-    def setUp(self):
-        self.snippet = st.CompositeSnippet(st.SimpleSnippet('if'), '$', st.SimpleSnippet('i==1'))
-
     def test_repr(self):
+        self.snippet = st.CompositeSnippet(st.SimpleSnippet('if'), '$', st.SimpleSnippet('i==1'))
         self.assertEqual(str(self.snippet), 'if$i==1')
 
     def test_eq(self):
+        # should not be equal to any instance of any other type
+        self.assertTrue(st.SimpleSnippet('if') != 123)
+        self.assertTrue(st.CompositeSnippet(None, None, None) != 123)
+
         self.assertEqual(st.SimpleSnippet('if'),
                          st.SimpleSnippet('if'))
 
@@ -19,7 +21,10 @@ def test_eq(self):
 
         self.assertFalse(st.SimpleSnippet('if') != st.SimpleSnippet('if'))
 
+
     def test_compile(self):
+        self.assertIsNone(st.Snippet().compile())
+
         self.assertEqual(
             st.CompositeSnippet(
                 st.CompositeSnippet(st.SimpleSnippet('for'), '#', st.SimpleSnippet('i')),