Test for the repr module, contributed by Nick Mathewson.

This closes SF patch #440826.

Lib/test/test_repr.py

+"""
+  Test cases for the repr module
+  Nick Mathewson
+"""
+
+import unittest
+from test_support import run_unittest
+from repr import repr as r # Don't shadow builtin repr 
+
+
+def nestedTuple(nesting):
+    t = ()
+    for i in range(nesting):
+        t = (t,)
+    return t
+
+class ReprTests(unittest.TestCase):
+
+    def test_string(self):
+        eq = self.assertEquals
+        eq(r("abc"), "'abc'")
+        eq(r("abcdefghijklmnop"),"'abcdefghijklmnop'")
+
+        s = "a"*30+"b"*30
+        expected = `s`[:13] + "..." + `s`[-14:]
+        eq(r(s), expected)
+        
+        eq(r("\"'"), repr("\"'"))
+        s = "\""*30+"'"*100
+        expected = `s`[:13] + "..." + `s`[-14:]
+        eq(r(s), expected)
+
+    def test_container(self):
+        eq = self.assertEquals
+        # Tuples give up after 6 elements
+        eq(r(()), "()")
+        eq(r((1,)), "(1,)")
+        eq(r((1, 2, 3)), "(1, 2, 3)")
+        eq(r((1, 2, 3, 4, 5, 6)), "(1, 2, 3, 4, 5, 6)")
+        eq(r((1, 2, 3, 4, 5, 6, 7)), "(1, 2, 3, 4, 5, 6, ...)")
+
+        # Lists give up after 6 as well
+        eq(r([]), "[]")
+        eq(r([1]), "[1]")
+        eq(r([1, 2, 3]), "[1, 2, 3]")
+        eq(r([1, 2, 3, 4, 5, 6]), "[1, 2, 3, 4, 5, 6]")
+        eq(r([1, 2, 3, 4, 5, 6, 7]), "[1, 2, 3, 4, 5, 6, ...]")
+
+        # Dictionaries give up after 4.
+        eq(r({}), "{}")
+        d = {'alice': 1, 'bob': 2, 'charles': 3, 'dave': 4}
+        eq(r(d), "{'alice': 1, 'bob': 2, 'charles': 3, 'dave': 4}")
+        d['arthur'] = 1
+        eq(r(d), "{'alice': 1, 'arthur': 1, 'bob': 2, 'charles': 3, ...}")
+
+    def test_numbers(self):
+        eq = self.assertEquals
+        eq(r(123), repr(123))
+        eq(r(123L), repr(123L))
+        eq(r(1.0/3), repr(1.0/3))
+
+        n = 10L**100
+        expected = `n`[:18] + "..." + `n`[-19:]
+        eq(r(n), expected)
+
+    def test_instance(self):
+        eq = self.assertEquals
+        i1 = ClassWithRepr("a")
+        eq(r(i1), repr(i1))
+        
+        i2 = ClassWithRepr("x"*1000)
+        expected = `i2`[:13] + "..." + `i2`[-14:]
+        eq(r(i2), expected)
+
+        i3 = ClassWithFailingRepr()
+        eq(r(i3), ("<ClassWithFailingRepr instance at %x>"%id(i3)))
+
+    def test_nesting(self):
+        eq = self.assertEquals
+        # everything is meant to give up after 6 levels.
+        eq(r([[[[[[[]]]]]]]), "[[[[[[[]]]]]]]")
+        eq(r([[[[[[[[]]]]]]]]), "[[[[[[[...]]]]]]]")
+
+        eq(r(nestedTuple(6)), "(((((((),),),),),),)")
+        eq(r(nestedTuple(7)), "(((((((...),),),),),),)")
+
+        eq(r({ nestedTuple(5) : nestedTuple(5) }),
+           "{((((((),),),),),): ((((((),),),),),)}")
+        eq(r({ nestedTuple(6) : nestedTuple(6) }),
+           "{((((((...),),),),),): ((((((...),),),),),)}")
+
+        eq(r([[[[[[{}]]]]]]), "[[[[[[{}]]]]]]")
+        eq(r([[[[[[[{}]]]]]]]), "[[[[[[[...]]]]]]]")
+
+
+class ClassWithRepr:
+    def __init__(self, s):
+        self.s = s
+    def __repr__(self):
+        return "ClassWithLongRepr(%r)" % self.s
+
+
+class ClassWithFailingRepr:
+    def __repr__(self):
+        raise Exception("This should be caught by Repr.repr_instance")
+
+
+run_unittest(ReprTests)