Fix argument typing in decompress unit, attempt to fix lzw for small …

…inputs, add lzw test cases

refinery/units/compression/decompress.py

@@ -44,7 +44,7 @@ def __init__(
             'To determine whether a decompression algorithm was successful, the '
             'ratio of compressed size to decompressed size may at most be as large '
             'as this number, a floating point value R; default value is {default}.')
-        ) = 1,
+        ) = 1.0,
         min_ratio: Arg('-n', metavar='R', help=(
             'Require that compression ratios must be at least as large as R. This '
             'is a "too good to be true" heuristic against algorithms like lznt1 '

refinery/units/compression/lzw.py

@@ -68,11 +68,7 @@ def process(self, data: bytearray):
             ibuf = ibuf[posbits >> 3:]
             insize = len(ibuf)
             posbits = 0
-
-            if insize < LZW.EXTRA:
-                inbits = (insize - insize % n_bits) << 3
-            else:
-                inbits = (insize << 3) - (n_bits - 1)
+            inbits = (insize << 3) - (n_bits - 1)
 
             while inbits > posbits:
                 if free_entry > maxcode:

test/units/compression/test_lzw.py

@@ -14,3 +14,18 @@ def test_flareon10(self):
         L = self.load_pipeline
         test = next(data | L('xt7z forth.tap | xtmagtape [| pick 1 ]| lzw'))
         self.assertIn(secret, test)
+
+    def test_really_small_input(self):
+        data = bytes.fromhex("1F9D9061C48C01")
+        test = data | self.load() | ...
+        self.assertEqual(b"abc", test)
+
+    def test_slighly_larger_input(self):
+        data = bytes.fromhex(
+            "1F9D9041840C2152C4C8112449942C61D2C4C9132851A44CA152C5CA152C5"
+            "9B4041C58F060C2850D1F469C58F162C68D040D2254C8D0214489142D62D4"
+            "2830A54796215F929479B266C795205D8E8C69528B02")
+        test = data | self.load() | ...
+        self.assertEqual((b"ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                          b"ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                          b"ABCDEFGHIJKLMNOPQRSTUVWXYZ\n"), test)