Fix default value in env variables handled like variable name (#684)

docs/releasenotes/unreleased/fixes.1.rst

@@ -0,0 +1,14 @@
+Handle default default of environment variable in RenameVariables (#677)
+------------------------------------------------------------------------
+
+``RenameVariables`` did not handle default value of environment variable correctly. Now following code::
+
+    Set Test Variable    ${local variable}    %{env variable=string message}
+    Log    %{MY_ENV=${global}}
+    Log    %{my env=${global} with extra}
+
+should be transformed to::
+
+    Set Test Variable    ${local_variable}    %{ENV_VARIABLE=string message}
+    Log    %{MY_ENV=${GLOBAL}}
+    Log    %{MY_ENV=${DEFAULT} with extra string}

robotidy/transformers/RenameVariables.py

@@ -444,7 +444,15 @@ def rename_value(self, value: str, variable_case: str, is_var: bool = False):
                     name += match.before
             # inline eval will start and end with {}
             if not (match.base.startswith("{") and match.base.endswith("}")):
-                base = self.rename_value(match.base, variable_case=variable_case, is_var=True)
+                # handle environment variable with default %{ENV=default}
+                if match.identifier == "%" and "=" in match.base:
+                    base, default = match.base.split("=", maxsplit=1)
+                    default = self.rename_value(default, variable_case=variable_case, is_var=False)
+                else:
+                    base, default = match.base, ""
+                base = self.rename_value(base, variable_case=variable_case, is_var=True)
+                if default:
+                    base = f"{base}={default}"
                 base = f"{match.name[:2]}{base}}}"
             else:
                 base = match.name

tests/atest/transformers/RenameVariables/expected/configure_ignore_vars.robot

@@ -27,6 +27,9 @@ Path and line separators
 Environment variable
     Log    %{APPLICATION_PORT=8080}
     Log    %{env_var}
+    Set Test Variable    ${LOCAL_VARIABLE}    %{ENV_VARIABLE=string message}
+    Log    %{MY_ENV=${DEFAULT}}
+    Log    %{MY_ENV=${DEFAULT} with extra}
 
 True and False
     IF    $True

tests/atest/transformers/RenameVariables/expected/excluded_vars.robot

@@ -27,6 +27,9 @@ Path and line separators
 Environment variable
     Log    %{APPLICATION_PORT=8080}
     Log    %{ENV_VAR}
+    Set Test Variable    ${LOCAL_VARIABLE}    %{ENV_VARIABLE=string message}
+    Log    %{MY_ENV=${DEFAULT}}
+    Log    %{MY_ENV=${DEFAULT} with extra}
 
 True and False
     IF    $True

tests/atest/transformers/RenameVariables/source/excluded_vars.robot

@@ -27,6 +27,9 @@ Path and line separators
 Environment variable
     Log    %{application_port=8080}
     Log    %{env_var}
+    Set Test Variable    ${local variable}    %{env variable=string message}
+    Log    %{MY_ENV=${default}}
+    Log    %{my env=${DEFAULT} with extra}
 
 True and False
     IF    $True