Introduce signal testing

This adds a dependency on pytest-qt.
Sadly the MultiSignalBlocker via `qtbot.waitSignals` (plural) doesn't
quite work for me yet, hence it's a bit ugly with multiple context
managers needed. But: Otherwise seems to be fine and most importantly,
waiting for signals to be received appears to work properly.

.appveyor.yml

@@ -64,7 +64,7 @@ environment:
     - ID: Ubu20
       DTS: datalad_gooey
       APPVEYOR_BUILD_WORKER_IMAGE: Ubuntu2004
-      INSTALL_SYSPKGS: python3-virtualenv
+      INSTALL_SYSPKGS: python3-virtualenv xvfb
       # system git-annex is way too old, use better one
       INSTALL_GITANNEX: git-annex -m deb-url --url http://snapshot.debian.org/archive/debian/20210906T204127Z/pool/main/g/git-annex/git-annex_8.20210903-1_amd64.deb
       CODECOV_BINARY: https://uploader.codecov.io/latest/linux/codecov

.github/workflows/test_crippledfs.yml

@@ -16,13 +16,15 @@ jobs:
         #sudo sed -e 's|\(deb.*data\)|#\1|' -e 's|/debian |/debian-devel |' /etc/apt/sources.list.d/neurodebian.sources.list | sudo tee /etc/apt/sources.list.d/neurodebian-devel.sources.list
         sudo apt-get update -qq
         sudo apt-get install eatmydata
-        sudo eatmydata apt-get install git-annex-standalone dosfstools
+        sudo eatmydata apt-get install git-annex-standalone dosfstools xvfb
         # 500 MB VFAT FS in a box
         sudo dd if=/dev/zero of=/crippledfs.img count=500 bs=1M
         sudo mkfs.vfat /crippledfs.img
         # mount
         sudo mkdir /crippledfs
         sudo mount -o "uid=$(id -u),gid=$(id -g)" /crippledfs.img /crippledfs
+    - name: Qt dependencies
+      uses: tlambert03/setup-qt-libs@v1
     - name: Set up environment
       run: |
         git config --global user.email "test@github.land"

datalad_gooey/tests/test_dataladcmd_exec.py

@@ -1,6 +1,48 @@
+from datalad.tests.utils_pytest import (
+    assert_equal,
+    assert_in,
+    assert_result_count,
+)
 
 from ..dataladcmd_exec import GooeyDataladCmdExec
 
 
-def test_GooeyDataladCmdExec():
-    GooeyDataladCmdExec()
+def test_GooeyDataladCmdExec(qtbot):
+
+    executor = GooeyDataladCmdExec()
+
+    cmd = 'nonsense'
+    with qtbot.waitSignal(executor.execution_failed) as block_for_fail, \
+            qtbot.assertNotEmitted(executor.execution_started), \
+            qtbot.assertNotEmitted(executor.execution_finished), \
+            qtbot.assertNotEmitted(executor.results_received):
+        executor.execute(cmd, {}, {})
+
+    # Note: blocker.args delivers the arguments to the signal
+    assert_equal(block_for_fail.args[1], "nonsense")
+    assert_in("module 'datalad.api' has no attribute 'nonsense'",
+              block_for_fail.args[-1].format_short())
+
+    cmd = 'wtf'
+    # MultSignalBlocker via waitSignals() doesn't "work". It blocks
+    # correctly, but signal args are inaccessible contrary to the pytest-qt
+    # docs. Hence, use the uglier way here:
+    with qtbot.waitSignal(executor.execution_started) as block_start, \
+            qtbot.waitSignal(executor.execution_finished) as block_finish, \
+            qtbot.waitSignal(executor.results_received) as block_result,  \
+            qtbot.assertNotEmitted(executor.execution_failed):
+
+        executor.execute(cmd, {}, {})
+
+    # command
+    assert_equal(block_start.args[1], "wtf")
+    assert_equal(block_finish.args[1], "wtf")
+    # thread_id matches:
+    assert_equal(block_start.args[0], block_finish.args[0])
+    # results received:
+    # command class
+    assert_equal(block_result.args[0].__qualname__,
+                 'WTF')
+    # actual results:
+    res = block_result.args[1]
+    assert_result_count(res, 1, action="wtf", status="ok")

requirements-devel.txt

@@ -1,6 +1,8 @@
 # requirements for a development environment
 pytest
 pytest-cov
+pytest-qt
+pytest-xvfb
 coverage
 sphinx
 sphinx_rtd_theme