Fix installer option inconsistency between EXE/MSI

constructor/briefcase.py

@@ -367,7 +367,8 @@ def create_install_options_list(info: dict) -> list[dict]:
                     "name": f"{script_type}_install_script",
                     "title": f"{script_type.capitalize()}-install script",
                     "description": script_description,
-                    "default": False,
+                    # Mirror NSIS: default to enabled when the script exists.
+                    "default": bool(script),
                 }
             )
 

examples/scripts/post_install.bat

@@ -2,19 +2,23 @@ echo Added by post-install script > "%PREFIX%\post_install_sentinel.txt"
 if not "%INSTALLER_NAME%" == "Scripts" exit 1
 if not "%INSTALLER_VER%" == "1.0.0" exit 1
 if not "%INSTALLER_PLAT%" == "win-64" exit 1
-if not "%INSTALLER_TYPE%" == "EXE" exit 1
-if not "%INSTALLER_UNATTENDED%" == "1" exit 1
+if not "%INSTALLER_TYPE%" == "EXE" if not "%INSTALLER_TYPE%" == "MSI" exit 1
+rem INSTALLER_UNATTENDED is not yet set by MSI installers (see conda/constructor#1276).
+if "%INSTALLER_TYPE%" == "EXE" if not "%INSTALLER_UNATTENDED%" == "1" exit 1
 if "%PREFIX%" == "" exit 1
 if not "%CUSTOM_VARIABLE_1%" == "FIR$T-CUSTOM_STRING WITH SPACES AND @*! CHARACTERS" exit 1
 if not "%CUSTOM_VARIABLE_2%" == "$ECOND-CUSTOM_STRING WITH SPACES AND @*! CHARACTERS" exit 1
 if not exist "%PREFIX%\pre_install_sentinel.txt" exit 1
 
-if not exist "%INSTALLER_PATH%" (
-  echo ERROR: "INSTALLER_PATH=%INSTALLER_PATH%" points to a file that does not exist!
-  exit 1
-)
+rem INSTALLER_PATH and INSTALLER_PLUGINSDIR are only set by EXE installers.
+if "%INSTALLER_TYPE%" == "EXE" (
+  if not exist "%INSTALLER_PATH%" (
+    echo ERROR: "INSTALLER_PATH=%INSTALLER_PATH%" points to a file that does not exist!
+    exit 1
+  )
 
-if not exist "%INSTALLER_PLUGINSDIR%" (
-  echo ERROR: "INSTALLER_PLUGINSDIR=%INSTALLER_PLUGINSDIR%" points to a directory that does not exist!
-  exit 1
+  if not exist "%INSTALLER_PLUGINSDIR%" (
+    echo ERROR: "INSTALLER_PLUGINSDIR=%INSTALLER_PLUGINSDIR%" points to a directory that does not exist!
+    exit 1
+  )
 )

examples/scripts/pre_install.bat

@@ -1,8 +1,9 @@
 if not "%INSTALLER_NAME%" == "Scripts" exit 1
 if not "%INSTALLER_VER%" == "1.0.0" exit 1
 if not "%INSTALLER_PLAT%" == "win-64" exit 1
-if not "%INSTALLER_TYPE%" == "EXE" exit 1
-if not "%INSTALLER_UNATTENDED%" == "1" exit 1
+if not "%INSTALLER_TYPE%" == "EXE" if not "%INSTALLER_TYPE%" == "MSI" exit 1
+rem INSTALLER_UNATTENDED is not yet set by MSI installers (see conda/constructor#1276).
+if "%INSTALLER_TYPE%" == "EXE" if not "%INSTALLER_UNATTENDED%" == "1" exit 1
 if "%PREFIX%" == "" exit 1
 if not "%CUSTOM_VARIABLE_1%" == "FIR$T-CUSTOM_STRING WITH SPACES AND @*! CHARACTERS" exit 1
 if not "%CUSTOM_VARIABLE_2%" == "$ECOND-CUSTOM_STRING WITH SPACES AND @*! CHARACTERS" exit 1

tests/test_briefcase.py

@@ -14,6 +14,7 @@
     _get_python_info,
     _get_script_env_variables,
     _setup_envs_commands,
+    create_install_options_list,
     create_uninstall_options_list,
     get_bundle_app_name,
     get_license,
@@ -645,6 +646,25 @@ def test_create_uninstall_options_list():
     assert "remove_config_files" in option_names
 
 
+@pytest.mark.parametrize("script_type", ["pre", "post"])
+def test_install_options_script_default_enabled(tmp_path, script_type):
+    """Pre/post-install script options default to enabled when a script exists.
+
+    This mirrors the NSIS installer, which checks the box by default when the
+    script is present (see nsis/main.nsi.tmpl).
+    """
+    script = tmp_path / f"{script_type}_install.bat"
+    script.write_text("@echo script")
+
+    info = mock_info.copy()
+    info[f"{script_type}_install"] = str(script)
+    info[f"{script_type}_install_desc"] = "Custom script description"
+
+    options = create_install_options_list(info)
+    option = next(opt for opt in options if opt["name"] == f"{script_type}_install_script")
+    assert option["default"] is True
+
+
 def test_render_templates_with_virtual_specs():
     """Test that virtual_specs check block is rendered when specs are provided."""
     info = mock_info.copy()