[TEST] add more test on otb segmentation apps

Even though not all errors are caught by these new tests, it could
expose if otb is broken or if processing api is changed to adopt
optional status of parameters at run-time.

`alg.processAlgorithm()` is running and failing correctly.
But `parameter.checkValueIsAcceptable()` and `alg.checkParameterValues()`
aren't working as expected.

Author: Rashad Kanavath

python/plugins/processing/tests/OtbAlgorithmsTest.py

@@ -34,6 +34,7 @@
 import tempfile
 from qgis.core import (QgsProcessingParameterNumber,
                        QgsApplication,
+                       QgsRasterLayer,
                        QgsMapLayer,
                        QgsProject,
                        QgsProcessingContext,
@@ -58,6 +59,68 @@
 
 class TestOtbAlgorithms(unittest.TestCase, AlgorithmsTestBase.AlgorithmsTest):
 
+    @staticmethod
+    def __input_raster_layer():
+        options = QgsRasterLayer.LayerOptions()
+        options.loadDefaultStyle = False
+        return QgsRasterLayer(os.path.join(AlgorithmsTestBase.processingTestDataPath(), 'raster.tif'),
+                              "raster_input",
+                              'gdal',
+                              options)
+
+    def test_bug21373_mode_vector(self):
+        """
+        This issue is reported on qgis bug tracker: #21373
+        This issue is reported on qgis-otb-plugin tracker: #30
+        """
+        context = QgsProcessingContext()
+        context.setProject(QgsProject.instance())
+        feedback = QgsProcessingFeedback()
+        parameters = {
+            'in': TestOtbAlgorithms.__input_raster_layer(),
+            'filter': 'meanshift',
+            'mode.vector.out': 'vector.shp'
+        }
+        alg = OtbAlgorithm('Segmentation', 'Segmentation', os.path.join(self.descrFolder, 'Segmentation.txt'))
+        results = alg.processAlgorithm(parameters, context, feedback)
+        self.assertDictEqual(results, {'mode.vector.out': 'vector.shp'})
+
+    def test_bug21373_mode_raster(self):
+        """
+        This issue is reported on qgis bug tracker: #21373
+        """
+        context = QgsProcessingContext()
+        context.setProject(QgsProject.instance())
+        feedback = QgsProcessingFeedback()
+        parameters = {
+            'in': TestOtbAlgorithms.__input_raster_layer(),
+            'filter': 'meanshift',
+            'mode': 'raster',
+            'mode.raster.out': 'raster.tif'
+        }
+        alg = OtbAlgorithm('Segmentation', 'Segmentation', os.path.join(self.descrFolder, 'Segmentation.txt'))
+        results = alg.processAlgorithm(parameters, context, feedback)
+        self.assertDictEqual(results, {'mode.raster.out': 'raster.tif'})
+
+    def test_bug21374_Fail(self):
+        """
+        This issue is reported on qgis bug tracker: #21374
+        """
+        outdir = tempfile.mkdtemp()
+        self.cleanup_paths.append(outdir)
+        context = QgsProcessingContext()
+        context.setProject(QgsProject.instance())
+        feedback = QgsProcessingFeedback()
+        parameters = {
+            'in': TestOtbAlgorithms.__input_raster_layer(),
+            'filter': 'cc',
+            'mode.vector.out': os.path.join(outdir, 'vector.shp')
+        }
+
+        alg = OtbAlgorithm('Segmentation', 'Segmentation', os.path.join(self.descrFolder, 'Segmentation.txt'))
+        ok, msg = alg.checkParameterValues(parameters, context)
+        self.assertFalse(ok, 'Algorithm failed checkParameterValues with result {}'.format(msg))
+
     def test_init_algorithms(self):
         """
         This test will read each otb algorithm in 'algs.txt'