Moved the damageFormula function to damageAction

module/data/action/damageAction.mjs

@@ -2,4 +2,17 @@ import DHBaseAction from './baseAction.mjs';
 
 export default class DHDamageAction extends DHBaseAction {
     static extraSchemas = [...super.extraSchemas, 'damage', 'target', 'effects'];
+
+    /**
+     * Return a display ready damage formula string
+     * @returns Formula string
+     */
+    getDamageFormula() {
+        const strings = [];
+        for (const { value } of this.damage.parts) {
+            strings.push(Roll.replaceFormulaData(value.getFormula(), this.actor?.getRollData() ?? {}));
+        }
+
+        return strings.join(' + ');
+    }
 }

module/data/fields/action/damageField.mjs

@@ -161,22 +161,6 @@ export default class DamageField extends fields.SchemaField {
         return formulaValue;
     }
 
-    /**
-     * Return a display ready damage formula string
-     * Must be called within Action context or similar.
-     * @param {Array<object>} parts Damage Parts
-     * @param {object} data Action getRollData
-     * @returns Formula string
-     */
-    static getFormulaString(parts) {
-        const strings = [];
-        for (const { value } of parts) {
-            strings.push(Roll.replaceFormulaData(value.getFormula(), this.actor?.getRollData() ?? {}));
-        }
-
-        return strings.join(' + ');
-    }
-
     /**
      * Prepare formulas for Damage Roll
      * Must be called within Action context or similar.

module/helpers/handlebarsHelper.mjs

@@ -36,7 +36,7 @@ export default class RegisterHandlebarsHelpers {
     }
 
     static damageFormula(attack) {
-        return game.system.api.fields.ActionFields.DamageField.getFormulaString.bind(attack)(attack.damage.parts);
+        return attack.getDamageFormula();
     }
 
     static formulaValue(formula, item) {