[processing] added tests for raster calculator

Conflicts:
	python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

Author: volaya

python/plugins/processing/tests/testdata/qgis_algorithm_tests.yaml

@@ -1824,3 +1824,33 @@ tests:
           - 'Minimum value: 03:29:40'
           - 'Maximum value: 15:29:22'
           - 'NULL \(missing\) values: 1'
+
+  - algorithm: qgis:rastercalculator
+    name: Raster Calculator with cellsize
+    params:
+      LAYERS:
+        params:
+          - name: dem.tif
+            type: raster
+        type: multi
+      CELLSIZE: 0.001
+      EXPRESSION: dem@1
+    results:
+      OUTPUT:
+        hash: ef97a22ee16e0e28bbdc0341449777b1527e37febc3c4339b2c057c9
+        type: rasterhash
+
+  - algorithm: qgis:rastercalculator
+    name: Raster Calculator 
+    params:
+      LAYERS:
+        params:
+          - name: dem.tif
+            type: raster
+        type: multi
+      CELLSIZE: 0.0
+      EXPRESSION: dem@1 * 2
+    results:
+      OUTPUT:
+        hash: fe6e018be13c5a3c17f3f4d0f0dc7686c628cb440b74c4642aa0c939
+        type: rasterhash