Update fake backend and fake provider to use versioned interface (#6286)

* Update fake backend and fake provider to use versioned interface

As was reported in #6280 the algorithms path doesn't work on minimal
examples of the Backend and Jobs interface and instead only works in
practice on ibmq, aer, or basic aer backends. Part of the reason for
this was that all the testing of algorithms is done exclusively on those
providers and there wasn't a minimal example to test against that
doesn't have legacy overhead (like qobj, etc). This commit updates the
fake providers and fake backends to use the latest version of the
provider, backend, and job interfaces and to be strictly compatible (ie
no qobj support). Besides exercising the new interface version it also
enables us to test the eventual fix for #6280 when it's available.

* Fix lint

* Add legacy fake backends using BaseBackend

qiskit/test/mock/__init__.py

@@ -20,10 +20,10 @@
 The mock devices are mainly for testing the compiler.
 """
 
-from .fake_provider import FakeProvider
+from .fake_provider import FakeProvider, FakeLegacyProvider
 from .fake_provider import FakeProviderFactory
-from .fake_backend import FakeBackend
-from .fake_job import FakeJob
+from .fake_backend import FakeBackend, FakeLegacyBackend
+from .fake_job import FakeJob, FakeLegacyJob
 from .fake_qobj import FakeQobj
 
 from .backends import *

qiskit/test/mock/backends/__init__.py

@@ -15,6 +15,7 @@
 Mocked versions of real quantum backends.
 """
 
+# BackendV1 Backends
 from .almaden import FakeAlmaden
 from .armonk import FakeArmonk
 from .athens import FakeAthens
@@ -50,3 +51,38 @@
 from .valencia import FakeValencia
 from .vigo import FakeVigo
 from .yorktown import FakeYorktown
+# Legacy Backends
+from .almaden import FakeLegacyAlmaden
+from .armonk import FakeLegacyArmonk
+from .athens import FakeLegacyAthens
+from .belem import FakeLegacyBelem
+from .boeblingen import FakeLegacyBoeblingen
+from .bogota import FakeLegacyBogota
+from .burlington import FakeLegacyBurlington
+from .cambridge import FakeLegacyCambridge
+from .cambridge import FakeLegacyCambridgeAlternativeBasis
+from .casablanca import FakeLegacyCasablanca
+from .essex import FakeLegacyEssex
+from .johannesburg import FakeLegacyJohannesburg
+from .lima import FakeLegacyLima
+from .london import FakeLegacyLondon
+from .manhattan import FakeLegacyManhattan
+from .melbourne import FakeLegacyMelbourne
+from .montreal import FakeLegacyMontreal
+from .mumbai import FakeLegacyMumbai
+from .ourense import FakeLegacyOurense
+from .paris import FakeLegacyParis
+from .poughkeepsie import FakeLegacyPoughkeepsie
+from .quito import FakeLegacyQuito
+from .rochester import FakeLegacyRochester
+from .rome import FakeLegacyRome
+from .rueschlikon import FakeLegacyRueschlikon
+from .santiago import FakeLegacySantiago
+from .singapore import FakeLegacySingapore
+from .sydney import FakeLegacySydney
+from .tenerife import FakeLegacyTenerife
+from .tokyo import FakeLegacyTokyo
+from .toronto import FakeLegacyToronto
+from .valencia import FakeLegacyValencia
+from .vigo import FakeLegacyVigo
+from .yorktown import FakeLegacyYorktown

qiskit/test/mock/backends/almaden/__init__.py

@@ -13,3 +13,4 @@
 """Mock almaden backend"""
 
 from .fake_almaden import FakeAlmaden
+from .fake_almaden import FakeLegacyAlmaden

qiskit/test/mock/backends/almaden/fake_almaden.py

@@ -15,10 +15,29 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeAlmaden(FakePulseBackend):
+class FakeAlmaden(fake_pulse_backend.FakePulseBackend):
+    """A fake Almaden backend.
+
+      00 ↔ 01 ↔ 02 ↔ 03 ↔ 04
+            ↕         ↕
+      05 ↔ 06 ↔ 07 ↔ 08 ↔ 09
+       ↕         ↕         ↕
+      10 ↔ 11 ↔ 12 ↔ 13 ↔ 14
+            ↕         ↕
+      15 ↔ 16 ↔ 17 ↔ 18 ↔ 19
+    """
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_almaden.json"
+    props_filename = "props_almaden.json"
+    defs_filename = "defs_almaden.json"
+    backend_name = "fake_almaden"
+
+
+class FakeLegacyAlmaden(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake Almaden backend.
 
       00 ↔ 01 ↔ 02 ↔ 03 ↔ 04

qiskit/test/mock/backends/armonk/__init__.py

@@ -13,3 +13,4 @@
 """Mock armonk backend"""
 
 from .fake_armonk import FakeArmonk
+from .fake_armonk import FakeLegacyArmonk

qiskit/test/mock/backends/armonk/fake_armonk.py

@@ -15,10 +15,23 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeArmonk(FakePulseBackend):
+class FakeArmonk(fake_pulse_backend.FakePulseBackend):
+    """A fake 1 qubit backend.
+
+      0
+    """
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_armonk.json"
+    props_filename = "props_armonk.json"
+    defs_filename = "defs_armonk.json"
+    backend_name = "fake_armonk"
+
+
+class FakeLegacyArmonk(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake 1 qubit backend.
 
       0

qiskit/test/mock/backends/athens/__init__.py

@@ -13,3 +13,4 @@
 """Mock athens backend"""
 
 from .fake_athens import FakeAthens
+from .fake_athens import FakeLegacyAthens

qiskit/test/mock/backends/athens/fake_athens.py

@@ -15,10 +15,20 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeAthens(FakePulseBackend):
+class FakeAthens(fake_pulse_backend.FakePulseBackend):
+    """A fake 5 qubit backend."""
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_athens.json"
+    props_filename = "props_athens.json"
+    defs_filename = "defs_athens.json"
+    backend_name = "fake_athens"
+
+
+class FakeLegacyAthens(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake 5 qubit backend."""
 
     dirname = os.path.dirname(__file__)

qiskit/test/mock/backends/belem/__init__.py

@@ -13,3 +13,4 @@
 """Mock belem backend"""
 
 from .fake_belem import FakeBelem
+from .fake_belem import FakeLegacyBelem

qiskit/test/mock/backends/belem/fake_belem.py

@@ -15,10 +15,20 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeBelem(FakePulseBackend):
+class FakeBelem(fake_pulse_backend.FakePulseBackend):
+    """A fake 5 qubit backend."""
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_belem.json"
+    props_filename = "props_belem.json"
+    defs_filename = "defs_belem.json"
+    backend_name = "fake_belem"
+
+
+class FakeLegacyBelem(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake 5 qubit backend."""
 
     dirname = os.path.dirname(__file__)

qiskit/test/mock/backends/boeblingen/__init__.py

@@ -13,3 +13,4 @@
 """Mock boeblingen backend"""
 
 from .fake_boeblingen import FakeBoeblingen
+from .fake_boeblingen import FakeLegacyBoeblingen

qiskit/test/mock/backends/boeblingen/fake_boeblingen.py

@@ -15,10 +15,29 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeBoeblingen(FakePulseBackend):
+class FakeBoeblingen(fake_pulse_backend.FakePulseBackend):
+    """A fake Boeblingen backend.
+
+      00 ↔ 01 ↔ 02 ↔ 03 ↔ 04
+            ↕         ↕
+      05 ↔ 06 ↔ 07 ↔ 08 ↔ 09
+       ↕         ↕         ↕
+      10 ↔ 11 ↔ 12 ↔ 13 ↔ 14
+            ↕         ↕
+      15 ↔ 16 ↔ 17 ↔ 18 ↔ 19
+    """
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_boeblingen.json"
+    props_filename = "props_boeblingen.json"
+    defs_filename = "defs_boeblingen.json"
+    backend_name = "fake_boeblingen"
+
+
+class FakeLegacyBoeblingen(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake Boeblingen backend.
 
       00 ↔ 01 ↔ 02 ↔ 03 ↔ 04

qiskit/test/mock/backends/bogota/__init__.py

@@ -13,3 +13,4 @@
 """Mock bogota backend"""
 
 from .fake_bogota import FakeBogota
+from .fake_bogota import FakeLegacyBogota

qiskit/test/mock/backends/bogota/fake_bogota.py

@@ -15,33 +15,23 @@
 """
 
 import os
-import json
 
-from qiskit.providers.models import QasmBackendConfiguration, BackendProperties
-from qiskit.test.mock.fake_backend import FakeBackend
+from qiskit.test.mock import fake_qasm_backend
 
 
-class FakeBogota(FakeBackend):
+class FakeBogota(fake_qasm_backend.FakeQasmBackend):
     """A fake 5 qubit backend."""
 
-    def __init__(self):
-        dirname = os.path.dirname(__file__)
-        filename = "conf_bogota.json"
-        with open(os.path.join(dirname, filename)) as f_conf:
-            conf = json.load(f_conf)
-
-        configuration = QasmBackendConfiguration.from_dict(conf)
-        configuration.backend_name = 'fake_bogota'
-        self._defaults = None
-        self._properties = None
-        super().__init__(configuration)
-
-    def properties(self):
-        """Returns a snapshot of device properties"""
-        if not self._properties:
-            dirname = os.path.dirname(__file__)
-            filename = "props_bogota.json"
-            with open(os.path.join(dirname, filename)) as f_prop:
-                props = json.load(f_prop)
-            self._properties = BackendProperties.from_dict(props)
-        return self._properties
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_bogota.json"
+    props_filename = "props_bogota.json"
+    backend_name = "fake_bogota"
+
+
+class FakeLegacyBogota(fake_qasm_backend.FakeQasmLegacyBackend):
+    """A fake 5 qubit backend."""
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_bogota.json"
+    props_filename = "props_bogota.json"
+    backend_name = "fake_bogota"

qiskit/test/mock/backends/burlington/__init__.py

@@ -13,3 +13,4 @@
 """Mock burlington backend"""
 
 from .fake_burlington import FakeBurlington
+from .fake_burlington import FakeLegacyBurlington

qiskit/test/mock/backends/burlington/fake_burlington.py

@@ -15,10 +15,24 @@
 """
 
 import os
-from qiskit.test.mock.fake_qasm_backend import FakeQasmBackend
+from qiskit.test.mock import fake_qasm_backend
 
 
-class FakeBurlington(FakeQasmBackend):
+class FakeBurlington(fake_qasm_backend.FakeQasmBackend):
+    """A fake 5 qubit backend.
+
+     0 ↔ 1 ↔ 3 ↔ 4
+         ↕
+         2
+    """
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_burlington.json"
+    props_filename = "props_burlington.json"
+    backend_name = "fake_burlington"
+
+
+class FakeLegacyBurlington(fake_qasm_backend.FakeQasmLegacyBackend):
     """A fake 5 qubit backend.
 
      0 ↔ 1 ↔ 3 ↔ 4

qiskit/test/mock/backends/cambridge/__init__.py

@@ -14,3 +14,5 @@
 
 from .fake_cambridge import FakeCambridge
 from .fake_cambridge import FakeCambridgeAlternativeBasis
+from .fake_cambridge import FakeLegacyCambridge
+from .fake_cambridge import FakeLegacyCambridgeAlternativeBasis

qiskit/test/mock/backends/cambridge/fake_cambridge.py

@@ -15,10 +15,10 @@
 """
 
 import os
-from qiskit.test.mock.fake_qasm_backend import FakeQasmBackend
+from qiskit.test.mock import fake_qasm_backend
 
 
-class FakeCambridge(FakeQasmBackend):
+class FakeCambridge(fake_qasm_backend.FakeQasmBackend):
     """A fake Cambridge backend.
 
                00 ↔ 01 ↔ 02 ↔ 03 ↔ 04
@@ -46,3 +46,33 @@ class FakeCambridgeAlternativeBasis(FakeCambridge):
     def __init__(self):
         super().__init__()
         self._configuration.basis_gates = ['u', 'sx', 'p', 'cx', 'id']
+
+
+class FakeLegacyCambridge(fake_qasm_backend.FakeQasmLegacyBackend):
+    """A fake Cambridge backend.
+
+               00 ↔ 01 ↔ 02 ↔ 03 ↔ 04
+               ↕                    ↕
+               05                  06
+               ↕                    ↕
+     07 ↔ 08 ↔ 09 ↔ 10 ↔ 11 ↔ 12 ↔ 13 ↔ 14 ↔ 15
+     ↕                   ↕                    ↕
+     16                  17                  18
+     ↕                   ↕                    ↕
+     19 ↔ 20 ↔ 21 ↔ 22 ↔ 23 ↔ 24 ↔ 25 ↔ 26 ↔ 27
+    """
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_cambridge.json"
+    props_filename = "props_cambridge.json"
+    backend_name = "fake_cambridge"
+
+
+class FakeLegacyCambridgeAlternativeBasis(FakeLegacyCambridge):
+    """A fake Cambridge backend with alternate 1q basis gates."""
+
+    props_filename = "props_cambridge_alt.json"
+
+    def __init__(self):
+        super().__init__()
+        self._configuration.basis_gates = ['u', 'sx', 'p', 'cx', 'id']

qiskit/test/mock/backends/casablanca/__init__.py

@@ -13,3 +13,4 @@
 """Mock casablanca backend"""
 
 from .fake_casablanca import FakeCasablanca
+from .fake_casablanca import FakeLegacyCasablanca

qiskit/test/mock/backends/casablanca/fake_casablanca.py

@@ -15,10 +15,20 @@
 """
 
 import os
-from qiskit.test.mock.fake_pulse_backend import FakePulseBackend
+from qiskit.test.mock import fake_pulse_backend
 
 
-class FakeCasablanca(FakePulseBackend):
+class FakeCasablanca(fake_pulse_backend.FakePulseBackend):
+    """A fake 7 qubit backend."""
+
+    dirname = os.path.dirname(__file__)
+    conf_filename = "conf_casablanca.json"
+    props_filename = "props_casablanca.json"
+    defs_filename = "defs_casablanca.json"
+    backend_name = "fake_casablanca"
+
+
+class FakeLegacyCasablanca(fake_pulse_backend.FakePulseLegacyBackend):
     """A fake 7 qubit backend."""
 
     dirname = os.path.dirname(__file__)

qiskit/test/mock/backends/essex/__init__.py

@@ -13,3 +13,4 @@
 """Mock essex backend"""
 
 from .fake_essex import FakeEssex
+from .fake_essex import FakeLegacyEssex