CI should run with mpl backend = ps (#2949)

* new reference files

* drop the not matching files

* inputs

* linux and mac

* another one fails

* new ref file

* do not save

* do not remove

* windows

* different refs for different os

* shorter lines

* remove ref

* new refernces

* udpate ref

* clean the azure conf

* moving the env to Makefile

* azure results

* ref image

* make test_ci

* at import time

* the other test

* clean up and new ref

* save for windows

* new ref

* clean up azure conf

* removing backend selection in qiskit/visualization/matplotlib.py

* add backend selection in testing

* lint

* tight

* backend in ci

* .

* drop

* do not remove and copy

* copy results

* save everything

* new ref

* skip these tests if matplotlib is not installed

* TestGraphDist only if HAS_MATPLOTLIB

* lint

* only under failing condition

* new ref

* rest of the artifacts

* Update azure-pipelines.yml

* twice in the same job

* Fix stray whitespace yaml syntax issue

* display name

azure-pipelines.yml

@@ -48,8 +48,6 @@ stages:
     - job: 'Linux_Tests'
       pool: {vmImage: 'ubuntu-16.04'}
       condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags'))
-      variables:
-        MPLBACKEND: ps
       strategy:
         matrix:
           Python35:
@@ -59,7 +57,6 @@ stages:
           inputs:
             versionSpec: '$(python.version)'
           displayName: 'Use Python $(python.version)'
-    
         - bash: |
             set -e
             python -m pip install --upgrade pip
@@ -72,6 +69,18 @@ stages:
             set -e
             stestr run
           displayName: 'Run tests'
+        - task: CopyFiles@2
+          condition: failed()
+          displayName: 'Copy images'
+          inputs:
+            contents: '**/*.png'
+            targetFolder: $(Build.ArtifactStagingDirectory)
+        - task: PublishBuildArtifacts@1
+          condition: failed()
+          displayName: 'Publish images'
+          inputs:
+            pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+            artifactName: 'drop_linux'
         - bash: |
             set -e
             pip install -U junitxml
@@ -113,8 +122,6 @@ stages:
     - job: 'MacOS_HighSierra_Tests'
       pool: {vmImage: 'macOS-10.13'}
       condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags'))
-      variables:
-        MPLBACKEND: ps
       strategy:
         matrix:
           Python35:
@@ -136,6 +143,18 @@ stages:
             set -e
             stestr run
           displayName: 'Run tests'
+        - task: CopyFiles@2
+          condition: failed()
+          displayName: 'Copy images'
+          inputs:
+            contents: '**/*.png'
+            targetFolder: $(Build.ArtifactStagingDirectory)
+        - task: PublishBuildArtifacts@1
+          condition: failed()
+          displayName: 'Publish images'
+          inputs:
+            pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+            artifactName: 'drop_macos'
         - bash: |
             set -e
             pip install -U junitxml
@@ -154,8 +173,6 @@ stages:
     - job: 'Windows_Tests'
       pool: {vmImage: 'vs2017-win2016'}
       condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags'))
-      variables:
-        MPLBACKEND: ps
       strategy:
         matrix:
           Python35:
@@ -181,6 +198,18 @@ stages:
             set -e
             stestr run
           displayName: 'Run tests'
+        - task: CopyFiles@2
+          condition: failed()
+          displayName: 'Copy images'
+          inputs:
+            contents: '**/*.png'
+            targetFolder: $(Build.ArtifactStagingDirectory)
+        - task: PublishBuildArtifacts@1
+          condition: failed()
+          displayName: 'Publish images'
+          inputs:
+            pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+            artifactName: 'drop_windows'
         - bash: |
             set -e
             pip install -U junitxml
@@ -196,8 +225,6 @@ stages:
     - job: 'Linux_Tests'
       pool: {vmImage: 'ubuntu-16.04'}
       condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags'))
-      variables:
-        MPLBACKEND: ps
       strategy:
         matrix:
           Python36:
@@ -221,6 +248,18 @@ stages:
             set -e
             stestr run
           displayName: 'Run tests'
+        - task: CopyFiles@2
+          condition: failed()
+          displayName: 'Copy images'
+          inputs:
+            contents: '**/*.png'
+            targetFolder: $(Build.ArtifactStagingDirectory)
+        - task: PublishBuildArtifacts@1
+          condition: failed()
+          displayName: 'Publish images'
+          inputs:
+            pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+            artifactName: 'drop_linux'
         - bash: |
             set -e
             pip install -U junitxml
@@ -236,8 +275,6 @@ stages:
     - job: 'MacOS_HighSierra_Tests'
       pool: {vmImage: 'macOS-10.13'}
       condition: not(startsWith(variables['Build.SourceBranch'], 'refs/tags'))
-      variables:
-        MPLBACKEND: ps
       strategy:
         matrix:
           Python36:
@@ -261,6 +298,18 @@ stages:
             set -e
             stestr run --concurrency 2
           displayName: 'Run tests'
+        - task: CopyFiles@2
+          condition: failed()
+          displayName: 'Copy images'
+          inputs:
+            contents: '**/*.png'
+            targetFolder: $(Build.ArtifactStagingDirectory)
+        - task: PublishBuildArtifacts@1
+          condition: failed()
+          displayName: 'Publish images'
+          inputs:
+            pathtoPublish: '$(Build.ArtifactStagingDirectory)'
+            artifactName: 'drop_macos'
         - bash: |
             set -e
             pip install -U junitxml

qiskit/visualization/gate_map.py

@@ -160,7 +160,7 @@ def plot_gate_map(backend, figsize=None,
     if ax is None:
         fig, ax = plt.subplots(figsize=figsize)  # pylint: disable=invalid-name
         ax.axis('off')
-        fig.tight_layout()
+        fig.set_tight_layout(True)
 
     # set coloring
     if qubit_color is None:

test/python/visualization/test_circuit_matplotlib_drawer.py

@@ -48,8 +48,7 @@ class TestMatplotlibDrawer(QiskitVisualizationTestCase):
         expected.set_size_inches(2.508333333333333, 0.2508333333333333)
         return expected
 
-    @unittest.skipIf(not visualization.HAS_MATPLOTLIB,
-                     'matplotlib not available.')
+    @unittest.skipIf(not visualization.HAS_MATPLOTLIB, 'matplotlib not available.')
     def test_empty_circuit(self):
         qc = QuantumCircuit()
         filename = self._get_resource_path('current_pulse_matplotlib_ref.png')
@@ -63,9 +62,7 @@ class TestMatplotlibDrawer(QiskitVisualizationTestCase):
 
         self.assertImagesAreEqual(filename, expected_filename)
 
-    @unittest.skipIf(not visualization.HAS_MATPLOTLIB,
-                     'matplotlib not available.')
-    @unittest.skip('Test is unreliable on some platforms')
+    @unittest.skipIf(not visualization.HAS_MATPLOTLIB, 'matplotlib not available.')
     def test_plot_barriers(self):
         """Test to see that plotting barriers works.
         If it is set to False, no blank columns are introduced"""
@@ -117,8 +114,6 @@ class TestMatplotlibDrawer(QiskitVisualizationTestCase):
 
     @unittest.skipIf(not visualization.HAS_MATPLOTLIB,
                      'matplotlib not available.')
-    @unittest.skip('Test is unreliable on some platforms')
-    @unittest.skipIf(os.name == 'nt', 'Rendered image differs on windows')
     def test_long_name(self):
         """Test to see that long register names can be seen completely
         As reported in #2605
@@ -135,20 +130,17 @@ class TestMatplotlibDrawer(QiskitVisualizationTestCase):
         circuit.h(qr)
         circuit.h(qr)
 
-        long_name_filename = self._get_resource_path('current_long_name_matplotlib_ref.png')
-        visualization.circuit_drawer(circuit, output='mpl',
-                                     filename=long_name_filename)
-        self.addCleanup(os.remove, long_name_filename)
+        filename = self._get_resource_path('current_%s_long_name_matplotlib.png' % os.name)
+        visualization.circuit_drawer(circuit, output='mpl', filename=filename)
+        # self.addCleanup(os.remove, filename)
 
         ref_filename = self._get_resource_path(
-            'visualization/references/matplotlib_long_name_ref.png')
+            'visualization/references/%s_long_name_matplotlib.png' % os.name)
 
-        self.assertImagesAreEqual(ref_filename, long_name_filename)
+        self.assertImagesAreEqual(ref_filename, filename)
 
     @unittest.skipIf(not visualization.HAS_MATPLOTLIB,
                      'matplotlib not available.')
-    @unittest.skip('Test is unreliable on some platforms')
-    @unittest.skipIf(os.name == 'nt', 'Rendered image differs on windows')
     def test_conditional(self):
         """Test that circuits with conditionals draw correctly
         """

test/python/visualization/test_gate_map.py

@@ -15,15 +15,19 @@
 """A test for visualizing device coupling maps"""
 import unittest
 import os
-import matplotlib.pyplot as plt
+
 from ddt import ddt, data
 from qiskit.test.mock import FakeProvider
 from qiskit.test import QiskitTestCase
 from qiskit.visualization.gate_map import _GraphDist, plot_gate_map, plot_circuit_layout
+from qiskit.tools.visualization import HAS_MATPLOTLIB
 from qiskit import QuantumRegister, QuantumCircuit
 from qiskit.transpiler import Layout
 from .visualization import path_to_diagram_reference, QiskitVisualizationTestCase
 
+if HAS_MATPLOTLIB:
+    import matplotlib.pyplot as plt
+
 
 @ddt
 class TestGateMap(QiskitVisualizationTestCase):
@@ -32,18 +36,20 @@ class TestGateMap(QiskitVisualizationTestCase):
                            not (x.configuration().simulator or x.configuration().n_qubits == 2),
                            FakeProvider().backends()))
 
-    def test_plot_gate_map(self):
+    @data(*backends)
+    @unittest.skipIf(not HAS_MATPLOTLIB, 'matplotlib not available.')
+    def test_plot_gate_map(self, backend):
         """ tests plotting of gate map of a device (20 qubit, 16 qubit, 14 qubit and 5 qubit)"""
-        for backend in self.backends:
-            n = backend.configuration().n_qubits
-            img_ref = path_to_diagram_reference(str(n) + "bit_quantum_computer.png")
-            filename = "temp.png"
-            fig = plot_gate_map(backend)
-            fig.savefig(filename, bbox_inches="tight")
-            self.assertImagesAreEqual(filename, img_ref, 0.2)
-            os.remove(filename)
+        n = backend.configuration().n_qubits
+        img_ref = path_to_diagram_reference(str(n) + "bit_quantum_computer.png")
+        filename = "temp.png"
+        fig = plot_gate_map(backend)
+        fig.savefig(filename)
+        self.assertImagesAreEqual(filename, img_ref, 0.2)
+        os.remove(filename)
 
     @data(*backends)
+    @unittest.skipIf(not HAS_MATPLOTLIB, 'matplotlib not available.')
     def test_plot_circuit_layout(self, backend):
         """ tests plot_circuit_layout for each device"""
         layout_length = int(backend._configuration.n_qubits / 2)
@@ -54,11 +60,12 @@ class TestGateMap(QiskitVisualizationTestCase):
         img_ref = path_to_diagram_reference(str(n) + "_plot_circuit_layout.png")
         filename = str(n) + "_plot_circuit_layout_result.png"
         fig = plot_circuit_layout(circuit, backend)
-        fig.savefig(filename, bbox_inches="tight")
+        fig.savefig(filename)
         self.assertImagesAreEqual(filename, img_ref, 0.1)
         os.remove(filename)
 
 
+@unittest.skipIf(not HAS_MATPLOTLIB, 'matplotlib not available.')
 class TestGraphDist(QiskitTestCase):
     """ tests _GraphdDist functions """
 

test/python/visualization/visualization.py

@@ -19,9 +19,12 @@ Useful for refactoring purposes."""
 
 import os
 import unittest
+import matplotlib
 
 from qiskit.test import QiskitTestCase
 
+matplotlib.use('ps')
+
 
 def path_to_diagram_reference(filename):
     return os.path.join(_this_directory(), 'references', filename)