Merge pull request #703 from Foundation-Devices/sft-8192-rename-fake-test-doubles-to-mock-across-the-passport-test

### ports/stm32/boards/Passport/modules/tests/test_sflash.py
@@ -11,7 +11,7 @@
 sys.path.insert(1, os.path.join(sys.path[0], '..'))
 
 
-class FakePin:
+class MockPin:
     def __init__(self) -> None:
         self.level = True
 
@@ -22,12 +22,12 @@ def high(self):
         self.level = True
 
 
-class FakeSPIFlash:
+class MockSPIFlash:
     # 64 MBit memory - 8 KiB
     _MEMORY_SIZE = 8 * 1024 * 1024
 
     def __init__(self) -> None:
-        self.cs = FakePin()
+        self.cs = MockPin()
         self.write_enable = False
         self.write_in_progress = False
         self.addr = None
@@ -115,15 +115,15 @@ def readinto(self, buf):
 
 
 @pytest.fixture
-def fake_spi_flash():
-    return FakeSPIFlash()
+def mock_spi_flash():
+    return MockSPIFlash()
 
 
 @pytest.fixture
-def spi_flash(fake_spi_flash):
+def spi_flash(mock_spi_flash):
     from sflash import SPIFlash
 
-    return SPIFlash(fake_spi_flash, fake_spi_flash.cs)
+    return SPIFlash(mock_spi_flash, mock_spi_flash.cs)
 
 
 def test_wait(spi_flash):

### ports/stm32/boards/Passport/modules/tests/unit/multisig_xpub_validation.py
@@ -14,7 +14,7 @@
 CHAIN_CODE = b'\x22' * 32
 
 
-class FakeNode:
+class MockNode:
     def __init__(self, public_key, chain_code):
         self._public_key = public_key
         self._chain_code = chain_code
@@ -29,7 +29,7 @@ def chain_code(self):
         return self._chain_code
 
 
-class FakeChain:
+class MockChain:
     ctype = 'BTC'
 
     @staticmethod
@@ -38,7 +38,7 @@ def serialize_public(_node, addr_fmt):
         return 'normalized-xpub'
 
 
-class FakeSensitiveValues:
+class MockSensitiveValues:
     def __enter__(self):
         return self
 
@@ -48,16 +48,16 @@ def __exit__(self, _exc_type, _exc, _traceback):
     @staticmethod
     def derive_path(derivation):
         assert derivation == DERIVATION
-        return FakeNode(PUBLIC_KEY, CHAIN_CODE)
+        return MockNode(PUBLIC_KEY, CHAIN_CODE)
 
 
 def check_node(node):
     original_import_xpub = multisig_wallet.import_xpub
     original_sensitive_values = stash.SensitiveValues
 
     try:
-        multisig_wallet.import_xpub = lambda _xpub: (node, FakeChain, AF_P2SH)
-        stash.SensitiveValues = FakeSensitiveValues
+        multisig_wallet.import_xpub = lambda _xpub: (node, MockChain, AF_P2SH)
+        stash.SensitiveValues = MockSensitiveValues
         xpubs = []
         is_mine = MultisigWallet.check_xpub(
             MY_XFP,
@@ -73,12 +73,12 @@ def check_node(node):
         stash.SensitiveValues = original_sensitive_values
 
 
-is_mine, xpubs = check_node(FakeNode(PUBLIC_KEY, CHAIN_CODE))
+is_mine, xpubs = check_node(MockNode(PUBLIC_KEY, CHAIN_CODE))
 assert is_mine
 assert xpubs == [(MY_XFP, DERIVATION, 'normalized-xpub')]
 
 try:
-    check_node(FakeNode(PUBLIC_KEY, b'\x33' * 32))
+    check_node(MockNode(PUBLIC_KEY, b'\x33' * 32))
 except AssertionError as exc:
     assert 'wrong xpub' in str(exc)
 else:

### ports/stm32/boards/Passport/modules/tests/unit/psbt_amounts.py
@@ -14,23 +14,23 @@
 P2WPKH_SCRIPT = b'\x00\x14' + (b'\x11' * 20)
 
 
-class FakePSBT:
+class MockPSBT:
     def __init__(self, values):
         self.fd = BytesIO(b''.join(CTxOut(value, P2WPKH_SCRIPT).serialize() for value in values))
         self.vout_start = 0
         self.num_outputs = len(values)
         self.total_value_out = None
 
 
-class FakePrevout:
+class MockPrevout:
     n = 0
 
 
-class FakeTxIn:
-    prevout = FakePrevout()
+class MockTxIn:
+    prevout = MockPrevout()
 
 
-class FakeInput:
+class MockInput:
     def __init__(self, value):
         self.value = value
         self.fully_signed = False
@@ -49,9 +49,9 @@ def determine_my_signing_key(self, _idx, _utxo, _xfp, _psbt):
         pass
 
 
-class FakeInputPSBT:
+class MockInputPSBT:
     def __init__(self, values):
-        self.inputs = [FakeInput(value) for value in values]
+        self.inputs = [MockInput(value) for value in values]
         self.my_xfp = 0
         self.total_value_in = None
         self.fee_is_verified = True
@@ -61,23 +61,23 @@ def __init__(self, values):
 
     def input_iter(self):
         for idx in range(self.num_inputs):
-            yield idx, FakeTxIn()
+            yield idx, MockTxIn()
 
 
 def read_outputs(values):
-    psbt = FakePSBT(values)
+    psbt = MockPSBT(values)
     parsed = [tx_out.nValue for _, tx_out in psbtObject.output_iter(psbt)]
     return psbt, parsed
 
 
 def read_inputs(values):
-    psbt = FakeInputPSBT(values)
+    psbt = MockInputPSBT(values)
     psbtObject.consider_inputs(psbt)
     return psbt
 
 
 def assert_invalid_outputs(values, invalid_idx):
-    psbt = FakePSBT(values)
+    psbt = MockPSBT(values)
     try:
         list(psbtObject.output_iter(psbt))
     except FatalPSBTIssue as exc:
@@ -88,7 +88,7 @@ def assert_invalid_outputs(values, invalid_idx):
 
 
 def assert_invalid_inputs(values, invalid_idx):
-    psbt = FakeInputPSBT(values)
+    psbt = MockInputPSBT(values)
     try:
         psbtObject.consider_inputs(psbt)
     except FatalPSBTIssue as exc:

### ports/stm32/boards/Passport/modules/tests/unit/psbt_fee.py
@@ -76,23 +76,23 @@ def assert_raises(exc_type, callback):
 assert_raises(AssertionError, lambda: script_mismatch.get_utxo(0))
 
 
-class FakePrevout:
+class MockPrevout:
     n = 0
 
 
-class FakeTxIn:
-    prevout = FakePrevout()
+class MockTxIn:
+    prevout = MockPrevout()
 
 
-class FakeNode:
+class MockNode:
     def __init__(self, public_key):
         self._public_key = public_key
 
     def public_key(self):
         return self._public_key
 
 
-class FakeSensitiveValues:
+class MockSensitiveValues:
     def __enter__(self):
         return self
 
@@ -102,14 +102,14 @@ def __exit__(self, _exc_type, _exc, _traceback):
     @staticmethod
     def derive_path(path, register=True):
         assert register
-        return FakeNode(DERIVED_PUBKEYS[path])
+        return MockNode(DERIVED_PUBKEYS[path])
 
 
-class FakeSigningInput:
+class MockSigningInput:
     pass
 
 
-class FakeInputPSBT:
+class MockInputPSBT:
     def __init__(self, psbt_input, my_xfp=0):
         self.inputs = [psbt_input]
         self.my_xfp = my_xfp
@@ -120,78 +120,78 @@ def __init__(self, psbt_input, my_xfp=0):
         self.warnings = []
 
     def input_iter(self):
-        yield 0, FakeTxIn()
+        yield 0, MockTxIn()
 
 
 verified_amounts = []
 original_verify_amount = history.verify_amount
 original_sensitive_values = stash.SensitiveValues
 history.verify_amount = lambda _prevout, amount, idx: verified_amounts.append((amount, idx))
-stash.SensitiveValues = FakeSensitiveValues
+stash.SensitiveValues = MockSensitiveValues
 try:
-    external_input_psbt = FakeInputPSBT(make_input(CTxOut(2000, P2WPKH_SCRIPT)))
+    external_input_psbt = MockInputPSBT(make_input(CTxOut(2000, P2WPKH_SCRIPT)))
     psbtObject.consider_inputs(external_input_psbt)
     assert not external_input_psbt.fee_is_verified
 
     owned_input = make_owned_input()
-    owned_input.validate(0, FakeTxIn(), MY_XFP)
-    owned_input_psbt = FakeInputPSBT(owned_input, MY_XFP)
+    owned_input.validate(0, MockTxIn(), MY_XFP)
+    owned_input_psbt = MockInputPSBT(owned_input, MY_XFP)
     psbtObject.consider_inputs(owned_input_psbt)
     assert owned_input_psbt.fee_is_verified
     assert owned_input.num_our_keys == 1
     assert owned_input.required_key == OWNED_PUBKEY
 
     forged_input = make_owned_input(FORGED_PUBKEY)
-    forged_input.validate(0, FakeTxIn(), MY_XFP)
-    forged_input_psbt = FakeInputPSBT(forged_input, MY_XFP)
+    forged_input.validate(0, MockTxIn(), MY_XFP)
+    forged_input_psbt = MockInputPSBT(forged_input, MY_XFP)
     assert_raises(AssertionError, lambda: psbtObject.consider_inputs(forged_input_psbt))
 finally:
     history.verify_amount = original_verify_amount
     stash.SensitiveValues = original_sensitive_values
 
 assert verified_amounts == [(2000, 0), (2000, 0)]
 
-multisig_input = FakeSigningInput()
+multisig_input = MockSigningInput()
 multisig_input.is_multisig = True
 multisig_input.required_key = {OWNED_PUBKEY}
 multisig_input.subpaths = {OWNED_PUBKEY: [MY_XFP, 0]}
 node, which_key = psbtInputProxy.get_signing_node(
-    multisig_input, FakeSensitiveValues(), MY_XFP, 0)
+    multisig_input, MockSensitiveValues(), MY_XFP, 0)
 assert node.public_key() == OWNED_PUBKEY
 assert which_key == OWNED_PUBKEY
 
-taproot_input = FakeSigningInput()
+taproot_input = MockSigningInput()
 taproot_input.is_multisig = False
 taproot_input.required_key = TAPROOT_PUBKEY
 taproot_input.subpaths = {}
 taproot_input.tap_subpaths = {TAPROOT_PUBKEY: ([MY_XFP, 1], [])}
 node, which_key = psbtInputProxy.get_signing_node(
-    taproot_input, FakeSensitiveValues(), MY_XFP, 0)
+    taproot_input, MockSensitiveValues(), MY_XFP, 0)
 assert node.public_key()[1:] == TAPROOT_PUBKEY
 assert which_key == TAPROOT_PUBKEY
 
-missing_path_input = FakeSigningInput()
+missing_path_input = MockSigningInput()
 missing_path_input.is_multisig = False
 missing_path_input.required_key = OWNED_PUBKEY
 missing_path_input.subpaths = {}
 missing_path_input.tap_subpaths = {}
 assert_raises(
     AssertionError,
     lambda: psbtInputProxy.get_signing_node(
-        missing_path_input, FakeSensitiveValues(), MY_XFP, 0),
+        missing_path_input, MockSensitiveValues(), MY_XFP, 0),
 )
 
 
-class FakeOutputProxy:
+class MockOutputProxy:
     is_change = False
 
     def validate(self, _idx, _txout, _xfp, _active_multisig):
         pass
 
 
-class FakeOutputPSBT:
+class MockOutputPSBT:
     def __init__(self, fee_is_verified):
-        self.outputs = [FakeOutputProxy()]
+        self.outputs = [MockOutputProxy()]
         self.total_value_out = 1000
         self.total_value_in = 5000
         self.fee_is_verified = fee_is_verified
@@ -210,33 +210,33 @@ def consider_dangerous_change(self, _xfp):
         pass
 
 
-unverified_fee_psbt = FakeOutputPSBT(external_input_psbt.fee_is_verified)
+unverified_fee_psbt = MockOutputPSBT(external_input_psbt.fee_is_verified)
 psbtObject.consider_outputs(unverified_fee_psbt)
 assert unverified_fee_psbt.warnings[0][0] == 'Unverified Fee'
 assert all(label not in {'Big Fee', 'Huge Fee'} for label, _text in unverified_fee_psbt.warnings)
 
-verified_fee_psbt = FakeOutputPSBT(owned_input_psbt.fee_is_verified)
+verified_fee_psbt = MockOutputPSBT(owned_input_psbt.fee_is_verified)
 psbtObject.consider_outputs(verified_fee_psbt)
 assert verified_fee_psbt.warnings[0][0] == 'Huge Fee'
 
 
-class FakeChain:
+class MockChain:
     def render_value(self, value):
         return str(value), 'sats'
 
 
-class FakeFlow:
-    chain = FakeChain()
+class MockFlow:
+    chain = MockChain()
 
     def __init__(self, psbt):
         self.psbt = psbt
 
 
-review = SignPsbtCommonFlow.render_warnings(FakeFlow(unverified_fee_psbt))
+review = SignPsbtCommonFlow.render_warnings(MockFlow(unverified_fee_psbt))
 assert 'Unverified' in review
 assert '4000 sats' not in review
 
-review = SignPsbtCommonFlow.render_warnings(FakeFlow(verified_fee_psbt))
+review = SignPsbtCommonFlow.render_warnings(MockFlow(verified_fee_psbt))
 assert '4000 sats' in review
 
 return_value.write(b'OK')

### ports/stm32/boards/Passport/modules/tests/unit/psbt_multisig_approval.py
@@ -28,28 +28,28 @@
 events = []
 
 
-class FakeImportMultisigWalletFlow:
+class MockImportMultisigWalletFlow:
     result = None
     calls = 0
 
     def __init__(self, wallet):
         assert wallet == 'proposed-wallet'
-        FakeImportMultisigWalletFlow.calls += 1
+        MockImportMultisigWalletFlow.calls += 1
 
     async def run(self):
         events.append('import')
         return self.result
 
 
-class FakePsbt:
+class MockPsbt:
     def __init__(self, needs_approval):
         self.multisig_import_needs_approval = needs_approval
         self.active_multisig = 'proposed-wallet'
         self.my_xfp = MY_XFP
         self.outputs = []
 
 
-class FakeOutput:
+class MockOutput:
     is_change = True
 
     def __init__(self, path, key):
@@ -64,15 +64,15 @@ def __init__(self, path, key):
             self.subpaths[key] = str_to_keypath(MY_XFP, path)
 
 
-class FakeNode:
+class MockNode:
     def __init__(self, key):
         self.key = key
 
     def public_key(self):
         return self.key
 
 
-class FakeSensitiveValues:
+class MockSensitiveValues:
     def __enter__(self):
         events.append('verify')
         return self
@@ -83,10 +83,10 @@ def __exit__(self, *_args):
     def derive_path(self, path):
         assert path in PATHS
         events.append(path)
-        return FakeNode(OWNED_KEYS[PATHS.index(path)])
+        return MockNode(OWNED_KEYS[PATHS.index(path)])
 
 
-class FakeErrorPage:
+class MockErrorPage:
     def __init__(self, text):
         assert text == ('Transaction rejected. Passport could not verify that the change address '
                         'belongs to this wallet.')
@@ -95,7 +95,7 @@ async def show(self):
         events.append('error')
 
 
-class FakeQuestionPage:
+class MockQuestionPage:
     def __init__(self, **_kwargs):
         pass
 
@@ -104,7 +104,7 @@ async def show(self):
         return True
 
 
-async def fake_spinner_task(_text, task, args=()):
+async def mock_spinner_task(_text, task, args=()):
     results = []
 
     async def on_done(*result):
@@ -115,12 +115,12 @@ async def on_done(*result):
     return results[0]
 
 
-async def fake_sign_psbt_task(on_done, _psbt):
+async def mock_sign_psbt_task(on_done, _psbt):
     events.append('sign')
     await on_done(None, None)
 
 
-class FakeSettings:
+class MockSettings:
     temporary_mode = True
 
     def __init__(self, policy=None):
@@ -134,11 +134,11 @@ def get(self, key, default=None):
         return default
 
 
-class FakeSignFlow(SignPsbtCommonFlow):
+class MockSignFlow(SignPsbtCommonFlow):
     def __init__(self, needs_approval):
         # Exercise state ordering without rendering pages or accessing device settings.
         Flow.__init__(self, initial_state=self.check_multisig_import)
-        self.psbt = FakePsbt(needs_approval)
+        self.psbt = MockPsbt(needs_approval)
         self.cancel_review = False
 
     async def show_transaction_details(self):
@@ -152,51 +152,51 @@ async def show_transaction_details(self):
 async def run_tests():
     original_settings = common.settings
     replacements = (
-        (flows, 'ImportMultisigWalletFlow', FakeImportMultisigWalletFlow),
-        (pages, 'ErrorPage', FakeErrorPage),
-        (pages, 'QuestionPage', FakeQuestionPage),
-        (stash, 'SensitiveValues', FakeSensitiveValues),
-        (utils, 'spinner_task', fake_spinner_task),
-        (sign_psbt_common_flow, 'spinner_task', fake_spinner_task),
-        (sign_psbt_common_flow, 'sign_psbt_task', fake_sign_psbt_task),
+        (flows, 'ImportMultisigWalletFlow', MockImportMultisigWalletFlow),
+        (pages, 'ErrorPage', MockErrorPage),
+        (pages, 'QuestionPage', MockQuestionPage),
+        (stash, 'SensitiveValues', MockSensitiveValues),
+        (utils, 'spinner_task', mock_spinner_task),
+        (sign_psbt_common_flow, 'spinner_task', mock_spinner_task),
+        (sign_psbt_common_flow, 'sign_psbt_task', mock_sign_psbt_task),
     )
     originals = [(module, name, getattr(module, name)) for module, name, _ in replacements]
 
     try:
         for module, name, replacement in replacements:
             setattr(module, name, replacement)
 
-        FakeImportMultisigWalletFlow.result = False
-        FakeImportMultisigWalletFlow.calls = 0
+        MockImportMultisigWalletFlow.result = False
+        MockImportMultisigWalletFlow.calls = 0
         events.clear()
-        flow = FakeSignFlow(needs_approval=True)
+        flow = MockSignFlow(needs_approval=True)
         assert await flow.run() is None
-        assert FakeImportMultisigWalletFlow.calls == 1
+        assert MockImportMultisigWalletFlow.calls == 1
         assert events == ['import']
 
-        FakeImportMultisigWalletFlow.result = True
+        MockImportMultisigWalletFlow.result = True
         for needs_approval in (True, False):
             events.clear()
-            flow = FakeSignFlow(needs_approval)
-            flow.psbt.outputs = [FakeOutput(PATHS[0], OWNED_KEYS[0])]
+            flow = MockSignFlow(needs_approval)
+            flow.psbt.outputs = [MockOutput(PATHS[0], OWNED_KEYS[0])]
             assert await flow.run() is flow.psbt
             expected = ['import'] if needs_approval else []
             assert events == expected + ['verify', PATHS[0], 'clear', 'review', 'confirm', 'sign']
 
         # Reviewing and cancelling a transaction without change must not open the key store.
-        payment = FakeOutput(PATHS[0], OTHER_KEY)
+        payment = MockOutput(PATHS[0], OTHER_KEY)
         payment.is_change = False
         for outputs in ([], [payment]):
             events.clear()
-            flow = FakeSignFlow(needs_approval=False)
+            flow = MockSignFlow(needs_approval=False)
             flow.psbt.outputs = outputs
             flow.cancel_review = True
             assert await flow.run() is None
             assert events == ['review']
 
         events.clear()
-        flow = FakeSignFlow(needs_approval=False)
-        flow.psbt.outputs = [FakeOutput(PATHS[0], OWNED_KEYS[0])]
+        flow = MockSignFlow(needs_approval=False)
+        flow.psbt.outputs = [MockOutput(PATHS[0], OWNED_KEYS[0])]
         flow.cancel_review = True
         assert await flow.run() is None
         assert events == ['verify', PATHS[0], 'clear', 'review']
@@ -206,8 +206,8 @@ async def run_tests():
         for path, owned_key in zip(PATHS, OWNED_KEYS):
             for key in (owned_key, OTHER_KEY):
                 events.clear()
-                flow = FakeSignFlow(needs_approval=False)
-                flow.psbt.outputs = [FakeOutput(path, key)]
+                flow = MockSignFlow(needs_approval=False)
+                flow.psbt.outputs = [MockOutput(path, key)]
                 result = await flow.run()
                 if key == owned_key:
                     assert result is flow.psbt
@@ -216,10 +216,10 @@ async def run_tests():
                     assert result is None
                     assert events == ['verify', path, 'clear', 'error']
 
-        common.settings = FakeSettings()
+        common.settings = MockSettings()
         assert get_multisig_policy() == MUSIG_ASK
 
-        common.settings = FakeSettings(policy=MUSIG_SKIP)
+        common.settings = MockSettings(policy=MUSIG_SKIP)
         assert get_multisig_policy() == MUSIG_SKIP
 
         return_value.write(b'OK')

### ports/stm32/boards/Passport/modules/tests/unit/restore_backup.py
@@ -7,7 +7,7 @@
 from tasks.restore_backup_task import restore_settings_from_backup
 
 
-class FakeSettings:
+class MockSettings:
     def __init__(self):
         self.values = {}
 
@@ -26,7 +26,7 @@ def set(self, key, value):
     'setting.backup_quiz': True,
 }
 
-settings = FakeSettings()
+settings = MockSettings()
 restore_settings_from_backup(vals, settings)
 
 assert settings.values == {
@@ -107,7 +107,7 @@ def clear_volatile(self):
         self.volatile.clear()
 
 
-class FakePa:
+class MockPa:
     def __init__(self):
         self.calls = []
 
@@ -118,26 +118,26 @@ async def new_main_secret(self, raw, chain):
         self.calls.append('new_main_secret')
 
 
-class FakeCardSlot:
+class MockCardSlot:
     def __enter__(self):
         return self
 
     def __exit__(self, *_args):
         return False
 
 
-class FakeFile:
+class MockFile:
     def close(self):
         pass
 
 
-class FakeBuilder:
+class MockBuilder:
     def read_file(self, fd, password, maxsize, progress_fcn=None):
         return ('backup.txt', BACKUP_CONTENTS)
 
 
-class FakeCompat7z:
-    Builder = FakeBuilder
+class MockCompat7z:
+    Builder = MockBuilder
 
     @staticmethod
     def check_file_headers(fd):
@@ -155,16 +155,16 @@ async def on_done(error):
 
 
 stored = StoredSettings()
-pa = FakePa()
+pa = MockPa()
 
 # Set the module-level open() before the try, so the finally can always undo it.
-restore_module.open = lambda path, mode: FakeFile()
+restore_module.open = lambda path, mode: MockFile()
 originals = (common.settings, common.pa, restore_module.compat7z, restore_module.CardSlot)
 try:
     common.settings = stored
     common.pa = pa
-    restore_module.compat7z = FakeCompat7z
-    restore_module.CardSlot = FakeCardSlot
+    restore_module.compat7z = MockCompat7z
+    restore_module.CardSlot = MockCardSlot
 
     assert asyncio.run(run_restore()) == [None]
 finally:

### ports/stm32/boards/Passport/modules/tests/unit/sign_psbt.py
@@ -8,35 +8,35 @@
 from utils import escape_text, recolor, stylize_address
 
 
-class FakeChain:
+class MockChain:
     def render_value(self, value):
         return (str(value), 'sats')
 
     def render_address(self, script):
         return 'OP_RETURN:\n{}'.format(script)
 
 
-class FakeFlow:
-    chain = FakeChain()
+class MockFlow:
+    chain = MockChain()
 
 
-class FakeAddressChain(FakeChain):
+class MockAddressChain(MockChain):
     def render_address(self, script):
         return script
 
 
-class FakeAddressFlow:
-    chain = FakeAddressChain()
+class MockAddressFlow:
+    chain = MockAddressChain()
 
 
-class FakeOutput:
+class MockOutput:
     def __init__(self, value, message):
         self.nValue = value
         self.scriptPubKey = message
 
 
 def assert_op_return_output(value, message):
-    rendered = SignPsbtCommonFlow.render_output(FakeFlow(), FakeOutput(value, message))
+    rendered = SignPsbtCommonFlow.render_output(MockFlow(), MockOutput(value, message))
 
     amount_label = rendered.find('Amount')
     amount = rendered.find('{} sats'.format(value))
@@ -55,15 +55,15 @@ def assert_op_return_output(value, message):
 destination_heading = recolor(HIGHLIGHT_TEXT_HEX, 'Destination')
 malicious_message = '{}\n0.00000001 BTC\n\n{}\nbc1qattacker'.format(
     amount_heading, destination_heading)
-rendered = SignPsbtCommonFlow.render_output(FakeFlow(), FakeOutput(1, malicious_message))
+rendered = SignPsbtCommonFlow.render_output(MockFlow(), MockOutput(1, malicious_message))
 assert escape_text(malicious_message) in rendered
 assert rendered.count('\n{}\n'.format(amount_heading)) == 1
 assert rendered.count('\n{}\n'.format(message_heading)) == 1
 assert rendered.count('\n{}\n'.format(destination_heading)) == 0
 assert malicious_message not in rendered
 
 address = 'bc1qvaliddestination'
-rendered = SignPsbtCommonFlow.render_output(FakeAddressFlow(), FakeOutput(42, address))
+rendered = SignPsbtCommonFlow.render_output(MockAddressFlow(), MockOutput(42, address))
 assert rendered == '\n{}\n42 sats\n\n{}\n{}'.format(
     amount_heading, destination_heading, stylize_address(address))