refactor: rename entropy length parameter

src/tests/test_bip85_derivation_path.py

@@ -0,0 +1,52 @@
+from local_bip85.bip85 import BIP85
+
+
+class DummyChild:
+    def PrivateKey(self):
+        return self
+
+    def Raw(self):
+        return self
+
+    def ToBytes(self):
+        return b"\x00" * 32
+
+
+class DummyCtx:
+    def __init__(self):
+        self.last_path = None
+
+    def DerivePath(self, path: str):
+        self.last_path = path
+        return DummyChild()
+
+
+def test_derivation_paths_for_entropy_lengths():
+    bip85 = BIP85(b"\x00" * 64)
+    ctx = DummyCtx()
+    bip85.bip32_ctx = ctx
+
+    vectors = [
+        (16, 12),
+        (24, 18),
+        (32, 24),
+    ]
+
+    for entropy_bytes, word_count in vectors:
+        bip85.derive_entropy(
+            index=0,
+            entropy_bytes=entropy_bytes,
+            app_no=39,
+            word_count=word_count,
+        )
+        assert ctx.last_path == f"m/83696968'/39'/0'/{word_count}'/0'"
+
+
+def test_default_word_count_from_entropy_bytes():
+    bip85 = BIP85(b"\x00" * 64)
+    ctx = DummyCtx()
+    bip85.bip32_ctx = ctx
+
+    bip85.derive_entropy(index=5, entropy_bytes=20, app_no=39)
+
+    assert ctx.last_path == "m/83696968'/39'/0'/20'/5'"