fix HyperFormula custom functions and add FIXED formula (#6645)

* fix custom HyperFormula functions

* add FIXED formula

* note

* [autofix.ci] apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

packages/loot-core/src/server/rules/action.ts

@@ -2,6 +2,7 @@
 import * as dateFns from 'date-fns';
 import * as Handlebars from 'handlebars';
 import { HyperFormula } from 'hyperformula';
+import enUS from 'hyperformula/i18n/languages/enUS';
 
 import { amountToInteger } from 'loot-core/shared/util';
 
@@ -10,9 +11,18 @@ import { currentDay, format, parseDate } from '../../shared/months';
 import { FIELD_TYPES } from '../../shared/rules';
 import { type TransactionForRules } from '../transactions/transaction-rules';
 
-import { CustomFunctionsPlugin } from './customFunctions';
+import {
+  CustomFunctionsPlugin,
+  customFunctionsTranslations,
+} from './customFunctions';
 import { assert } from './rule-utils';
 
+HyperFormula.registerLanguage('enUS', enUS);
+HyperFormula.registerFunctionPlugin(
+  CustomFunctionsPlugin,
+  customFunctionsTranslations,
+);
+
 const ACTION_OPS = [
   'set',
   'set-split-amount',
@@ -258,10 +268,9 @@ export class Action {
     }
 
     try {
-      HyperFormula.registerFunctionPlugin(CustomFunctionsPlugin);
-
       hfInstance = HyperFormula.buildEmpty({
         licenseKey: 'gpl-v3',
+        language: 'enUS',
       });
 
       const sheetName = hfInstance.addSheet('Sheet1');

packages/loot-core/src/server/rules/customFunctions.ts

@@ -15,6 +15,17 @@ export class CustomFunctionsPlugin extends FunctionPlugin {
       },
     );
   }
+
+  fixed(ast: ProcedureAst, state: InterpreterState) {
+    return this.runFunction(
+      ast.args,
+      state,
+      this.metadata('FIXED'),
+      (number: number, decimals: number = 0) => {
+        return Number(number).toFixed(decimals);
+      },
+    );
+  }
 }
 
 CustomFunctionsPlugin.implementedFunctions = {
@@ -29,4 +40,22 @@ CustomFunctionsPlugin.implementedFunctions = {
       },
     ],
   },
+  FIXED: {
+    method: 'fixed',
+    parameters: [
+      { argumentType: FunctionArgumentType.NUMBER },
+      {
+        argumentType: FunctionArgumentType.NUMBER,
+        optionalArg: true,
+        defaultValue: 0,
+      },
+    ],
+  },
+};
+
+export const customFunctionsTranslations = {
+  enUS: {
+    INTEGER_TO_AMOUNT: 'INTEGER_TO_AMOUNT',
+    FIXED: 'FIXED',
+  },
 };