Replace is dependency with native code

AGENTS.md

@@ -20,7 +20,7 @@ code in this repository.
   release).
 
 CI runs `npm run lint` then `npm test -- --ci --coverage --runInBand` against
-Node 20.x, 22.x, and 24.x. The package targets `node >= 20` and is CommonJS
+Node 22.x, 24.x, and 26.x. The package targets `node >= 22` and is CommonJS
 (`require` / `module.exports`).
 
 ## Architecture

package.json

@@ -40,7 +40,6 @@
     "test": "jest"
   },
   "dependencies": {
-    "is": "^3.3.2",
     "joi": "^18.2.4"
   },
   "devDependencies": {

src/adapters/base.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 const AdapterValidator = require('../validators/adapter')
 const NotImplementedError = require('../errors/not_implemented')
 
@@ -41,7 +39,7 @@ class BaseAdapter {
 
     const operatorMethod = `filter:${operator}`
 
-    if (is.fn(this[operatorMethod])) {
+    if (typeof this[operatorMethod] === 'function') {
       return this[operatorMethod](builder, filter)
     }
 

src/orchestrators/base.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 const cache = require('../services/cache_function')
 const NotImplementedError = require('../errors/not_implemented')
 const ValidationError = require('../errors/validation')
@@ -58,7 +56,7 @@ class BaseOrchestrator {
     const args = [this.querier.builder, values]
 
     this.querier.builder =
-      querierMethod && is.fn(this.querier[querierMethod])
+      querierMethod && typeof this.querier[querierMethod] === 'function'
         ? this.querier[querierMethod](...args)
         : this.querier.adapter[this.queryKey](...args)
 

src/parsers/filter.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 const BaseParser = require('./base')
 const flattenMap = require('../services/flatten_map')
 
@@ -95,7 +93,10 @@ class FilterParser extends BaseParser {
     const filters = []
 
     for (const [name, value] of entries) {
-      if (is.object(value)) {
+      // `Object.prototype.toString` is used instead of `typeof` so that arrays,
+      // `null`, and exotic objects (like `Date`) are treated as filter values
+      // rather than operator objects.
+      if (Object.prototype.toString.call(value) === '[object Object]') {
         filters.push(...this.parseObject(name, value))
       } else {
         filters.push(this.parseNonObject(name, value))

src/parsers/page.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 const BaseParser = require('./base')
 const flattenMap = require('../services/flatten_map')
 
@@ -60,7 +58,10 @@ class PageParser extends BaseParser {
 
     if (!this.query) {
       page = this.defaults
-    } else if (is.number(this.query) || is.string(this.query)) {
+    } else if (
+      typeof this.query === 'number' ||
+      typeof this.query === 'string'
+    ) {
       page = this.parseNumber()
     } else {
       page = this.parseObject()

src/parsers/sort.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 const BaseParser = require('./base')
 const flattenMap = require('../services/flatten_map')
 
@@ -89,9 +87,9 @@ class SortParser extends BaseParser {
 
     const sorts = []
 
-    if (is.string(this.query)) {
+    if (typeof this.query === 'string') {
       sorts.push(this.parseString(this.query))
-    } else if (is.array(this.query)) {
+    } else if (Array.isArray(this.query)) {
       sorts.push(...this.parseArray(this.query))
     } else {
       sorts.push(...this.parseObject(this.query))

src/schema.js

@@ -1,5 +1,3 @@
-const is = require('is')
-
 class Schema {
   constructor() {
     this.filters = new Map()
@@ -33,7 +31,7 @@ class Schema {
   }
 
   page(isEnabledOrOptions = true) {
-    if (is.bool(isEnabledOrOptions)) {
+    if (typeof isEnabledOrOptions === 'boolean') {
       this.pageOptions = { isEnabled: isEnabledOrOptions }
     } else {
       this.pageOptions = {