Deprecation warning for EWW_CPU_USAGE

crates/eww/src/config/inbuilt.rs

@@ -45,14 +45,6 @@ pub fn get_inbuilt_vars() -> HashMap<VarName, ScriptVarDefinition> {
         // @desc EWW_CPU - Information on the CPU cores: frequency and usage (No MacOS support)
         "EWW_CPU" => || Ok(DynVal::from(get_cpus())),
 
-        // TODO: Change this eventually, maybe implement an error system
-        // @desc EWW_CPU_USAGE - Outdated, use `EWW_CPU` instead
-        "EWW_CPU_USAGE" => {
-            log::warn!("EWW_CPU_BATTERY is deprecated, use EWW_CPU instead");
-            || Ok(DynVal::from(get_cpus()))
-        },
-
-
         // @desc EWW_NET - Bytes up/down on all interfaces
         "EWW_NET" => || Ok(DynVal::from(net())),
     }

crates/yuck/src/format_diagnostic.rs

@@ -184,15 +184,25 @@ impl ToDiagnostic for ValidationError {
                         "Hint: Define it as a global variable"
                     }
                 };
-                diag.with_notes(vec![format!(
-                    "Hint: If you meant to use the literal value \"{}\", surround the value in quotes",
-                    name
-                )])
+
+                let mut extra_notes =
+                    vec![format!("Hint: If you meant to use the literal value \"{}\", surround the value in quotes", name)];
+
+                if let Some(deprecation_note) = variable_deprecation_note(name.to_string()) {
+                    extra_notes.push(deprecation_note)
+                };
+
+                diag.with_notes(extra_notes)
             }
         }
     }
 }
 
+fn variable_deprecation_note(var_name: String) -> Option<String> {
+    (var_name == "EWW_CPU_USAGE")
+        .then(|| "Note: EWW_CPU_USAGE has recently been removed, and has now been renamed to EWW_CPU".to_string())
+}
+
 fn lalrpop_error_to_diagnostic<T: std::fmt::Display, E: Spanned + ToDiagnostic>(
     error: &lalrpop_util::ParseError<usize, T, E>,
     file_id: usize,