[widgets][algorithmeditor] Add helper method to update algorithm code

This will update the code from a python based algorithm
when changing type or making it an analyzer.

beat/editor/test/test_algorithmeditor.py

@@ -40,6 +40,7 @@ from ..widgets.algorithmeditor import ALGORITHM_TYPE
 from ..widgets.algorithmeditor import DEFAULT_SCHEMA_VERSION
 from ..widgets.algorithmeditor import DEFAULT_API_VERSION
 from ..widgets.algorithmeditor import migrate_to_api_v2
+from ..widgets.algorithmeditor import update_code
 
 from .conftest import sync_prefix
 from .conftest import prefix
@@ -97,6 +98,38 @@ class TestHelperMethods:
         assert v2_declaration["api_version"] == 2
         assert v2_declaration["type"] == "legacy"
 
+    @pytest.mark.parametrize(
+        ["algorithm_name", "new_type", "field_to_add"],
+        [
+            ("autonomous/add/1", "legacy", None),
+            ("autonomous/add/1", "sequential", None),
+            ("sequential/add/1", "autonomous", None),
+            ("sequential/add/1", "loop_user", None),
+            ("sequential/add/1", "loop", None),
+            ("autonomous/loop/1", "sequential", None),
+            ("autonomous/loop/1", "sequential", "results"),
+            ("autonomous/add/1", "sequential", "results"),
+        ],
+    )
+    def test_code_update(self, test_prefix, algorithm_name, new_type, field_to_add):
+        asset = Asset(test_prefix, AssetType.ALGORITHM, algorithm_name)
+
+        with open(asset.code_path, "rt") as code_file:
+            original_code = code_file.read()
+
+        declaration = asset.declaration
+        declaration["type"] = new_type
+        if field_to_add:
+            declaration[field_to_add] = None
+
+        asset.declaration = declaration
+        update_code(asset)
+
+        with open(asset.code_path, "rt") as code_file:
+            updated_code = code_file.read()
+
+        assert updated_code != original_code
+
 
 class TestPropertyEditor:
     """Test that the algorithm properties editor works as expected"""

beat/editor/widgets/algorithmeditor.py

@@ -24,6 +24,7 @@
 ###############################################################################
 
 import os
+import re
 
 from PyQt5.QtCore import pyqtSignal
 from PyQt5.QtCore import pyqtSlot
@@ -96,6 +97,49 @@ def migrate_to_api_v2(asset):
     return status, new_asset
 
 
+def update_code(asset):
+    declaration = asset.declaration
+    if declaration.get("language") == "python":
+        alg_type = declaration.get("type")
+        is_analyzer = "results" in declaration
+
+        with open(asset.code_path, "rt") as code_file:
+            lines = code_file.readlines()
+
+        process_line = None
+        validate_line = None
+        for index, line in enumerate(lines):
+            if "def process" in line:
+                process_line = index
+
+            if "def validate" in line:
+                validate_line = index
+
+        if process_line:
+            if is_analyzer:
+                lines[process_line] = re.sub(
+                    r"^(\s*).*(\s*)$",
+                    r"\g<1>{}\g<2>".format(ANALYZER_PROCESS_METHOD_MAP[alg_type]),
+                    lines[process_line],
+                )
+            elif alg_type in ALGORITHM_PROCESS_METHOD_MAP:
+                lines[process_line] = re.sub(
+                    r"^(\s*).*(\s*)$",
+                    r"\g<1>{}\g<2>".format(ALGORITHM_PROCESS_METHOD_MAP[alg_type]),
+                    lines[process_line],
+                )
+        elif alg_type != "loop":
+            lines.append("    {}\n".format(ALGORITHM_PROCESS_METHOD_MAP[alg_type]))
+            lines.append("        pass\n")
+
+        if alg_type == "loop" and not validate_line:
+            lines.append("    {}\n".format(LOOP_VALIDATE_METHOD))
+            lines.append("        pass\n")
+
+        with open(asset.code_path, "wt") as code_file:
+            code_file.write("".join(lines))
+
+
 class PropertyEditor(QWidget):
 
     dataChanged = pyqtSignal()