refactor: extract shared TypeScript rules in ESLint config

- Extract duplicated TypeScript rules into sharedTypeScriptRules constant
- Replace inline rule objects in both base and test configs with shared constant
- Maintains all original rules and configurations unchanged
- Improves maintainability by eliminating code duplication
- Follows DRY principle for better code organization

Author: AlmostBald-TRADING

clients/typescript/eslint.config.js

@@ -3,6 +3,26 @@ import typescript from '@typescript-eslint/eslint-plugin';
 import typescriptParser from '@typescript-eslint/parser';
 import globals from 'globals';
 
+// Shared TypeScript rules used by both base and test configurations
+const sharedTypeScriptRules = {
+  ...typescript.configs.recommended.rules,
+  '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
+  '@typescript-eslint/explicit-function-return-type': ['error', {
+    allowExpressions: true,
+    allowTypedFunctionExpressions: true
+  }],
+  // Enforce explicit return types for exported/public APIs
+  '@typescript-eslint/explicit-module-boundary-types': 'error',
+  '@typescript-eslint/no-explicit-any': 'error',
+  '@typescript-eslint/no-inferrable-types': 'off',
+  '@typescript-eslint/strict-boolean-expressions': ['error', {
+    allowNullableObject: true
+  }],
+  'prefer-const': 'error',
+  'no-var': 'error',
+  'no-unused-vars': 'off', // Turn off base rule as it can conflict with @typescript-eslint/no-unused-vars
+};
+
 export default [
   js.configs.recommended,
   {
@@ -29,24 +49,7 @@ export default [
     plugins: {
       '@typescript-eslint': typescript,
     },
-    rules: {
-      ...typescript.configs.recommended.rules,
-      '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
-      '@typescript-eslint/explicit-function-return-type': ['error', {
-        allowExpressions: true,
-        allowTypedFunctionExpressions: true
-      }],
-      // Enforce explicit return types for exported/public APIs
-      '@typescript-eslint/explicit-module-boundary-types': 'error',
-      '@typescript-eslint/no-explicit-any': 'error',
-      '@typescript-eslint/no-inferrable-types': 'off',
-      '@typescript-eslint/strict-boolean-expressions': ['error', {
-        allowNullableObject: true
-      }],
-      'prefer-const': 'error',
-      'no-var': 'error',
-      'no-unused-vars': 'off', // Turn off base rule as it can conflict with @typescript-eslint/no-unused-vars
-    },
+    rules: sharedTypeScriptRules,
   },
   {
     files: ['tests/**/*.ts', '**/*.test.ts', '**/*.spec.ts'],
@@ -75,23 +78,7 @@ export default [
     plugins: {
       '@typescript-eslint': typescript,
     },
-    rules: {
-      ...typescript.configs.recommended.rules,
-      '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
-      '@typescript-eslint/explicit-function-return-type': ['error', {
-        allowExpressions: true,
-        allowTypedFunctionExpressions: true
-      }],
-      '@typescript-eslint/explicit-module-boundary-types': 'error',
-      '@typescript-eslint/no-explicit-any': 'error',
-      '@typescript-eslint/no-inferrable-types': 'off',
-      '@typescript-eslint/strict-boolean-expressions': ['error', {
-        allowNullableObject: true
-      }],
-      'prefer-const': 'error',
-      'no-var': 'error',
-      'no-unused-vars': 'off',
-    },
+    rules: sharedTypeScriptRules,
   },
   {
     ignores: [