FIX: flexible boolean

issue: #199

Author: iwakitakuma

customSchemas.ts

@@ -1,12 +1,11 @@
 import { z } from "zod";
-import { pino } from 'pino';
+import { pino } from "pino";
 const DEFAULT_NULL = process.env.DEFAULT_NULL === "true";
 
-
 const logger = pino({
-  level: process.env.LOG_LEVEL || 'info',
+  level: process.env.LOG_LEVEL || "info",
   transport: {
-    target: 'pino-pretty',
+    target: "pino-pretty",
     options: {
       colorize: true,
       levelFirst: true,
@@ -15,11 +14,19 @@ const logger = pino({
   },
 });
 
-export const flexibleBoolean = z.preprocess((val) => {
-    if (typeof val === 'string') {
-        return val.toLowerCase()  === 'true';
-    }
+export const flexibleBoolean = z.preprocess(val => {
+  if (typeof val === "boolean") {
     return val;
+  }
+  let result = "false";
+  try {
+    result = String(val).toLowerCase();
+  } catch {
+    return false;
+  }
+  return result in ["true", "t", "1"];
 }, z.boolean());
 
-export const flexibleBooleanNullable = DEFAULT_NULL ? flexibleBoolean.nullable().default(null) : flexibleBoolean.nullable();
+export const flexibleBooleanNullable = DEFAULT_NULL
+  ? flexibleBoolean.nullable().default(null)
+  : flexibleBoolean.nullable();