Add boolean argument coercion helper

src/lib/string.ts

@@ -8,7 +8,7 @@ import {
     coerceArgToString,
     hasOwnProperty,
     LuaType,
-    coerceToBoolean
+    coerceArgToBoolean
 } from '../utils'
 
 const ROSETTA_STONE: Record<string, string> = {
@@ -125,7 +125,7 @@ function find(s: LuaType, pattern: LuaType, init: LuaType, plain: LuaType): (num
     const S = coerceArgToString(s, 'find', 1)
     const P = coerceArgToString(pattern, 'find', 2)
     const INIT = init === undefined ? 1 : coerceArgToNumber(init, 'find', 3)
-    const PLAIN = plain === undefined ? false : coerceToBoolean(plain)
+    const PLAIN = plain === undefined ? false : coerceArgToBoolean(plain, 'find', 4)
 
     // Regex
     if (!PLAIN) {

src/utils.ts

@@ -160,7 +160,7 @@ function coerceToString(val: LuaType, errorMessage?: string): string {
 function coerceArg<T>(
     value: LuaType,
     coerceFunc: (val: LuaType, errorMessage?: string) => T,
-    typ: 'number' | 'string',
+    typ: 'number' | 'string' | 'boolean',
     funcName: string,
     index: number
 ): T {
@@ -175,6 +175,10 @@ function coerceArgToString(value: LuaType, funcName: string, index: number): str
     return coerceArg<string>(value, coerceToString, 'string', funcName, index)
 }
 
+function coerceArgToBoolean(value: LuaType, funcName: string, index: number): boolean {
+    return coerceArg<boolean>(value, coerceToBoolean, 'boolean', funcName, index)
+}
+
 function coerceArgToTable(value: LuaType, funcName: string, index: number): Table {
     if (value instanceof Table) {
         return value
@@ -207,6 +211,7 @@ export {
     coerceToBoolean,
     coerceToNumber,
     coerceToString,
+    coerceArgToBoolean,
     coerceArgToNumber,
     coerceArgToString,
     coerceArgToTable,