feat(codemode): native coercion parity in interpreter (#37608)

packages/codemode/src/stdlib/date.ts

@@ -23,6 +23,8 @@ export const dateMethods = new Set([
   "getTimezoneOffset",
 ])
 
+export const dateStatics = new Set(["now", "parse", "UTC"])
+
 export const invokeDateStatic = (name: string, args: Array<unknown>, node: AstNode): number => {
   switch (name) {
     case "now":

packages/codemode/src/stdlib/json.ts

@@ -2,6 +2,8 @@ import { type AstNode, InterpreterRuntimeError, supportedSyntaxMessage } from ".
 import { typeofValue } from "../interpreter/references.js"
 import { copyIn, copyOut } from "../tool-runtime.js"
 
+export const jsonStatics = new Set(["parse", "stringify"])
+
 export const invokeJsonMethod = (name: string, args: Array<unknown>, node: AstNode): unknown => {
   switch (name) {
     case "stringify": {

packages/codemode/src/stdlib/object.ts

@@ -6,6 +6,8 @@ import { boundedData, coerceToString } from "./value.js"
 
 export const objectMethodsPreservingIdentity = new Set(["assign", "values", "entries", "fromEntries"])
 
+export const objectStatics = new Set(["keys", "values", "entries", "hasOwn", "is", "assign", "fromEntries"])
+
 export const invokeObjectMethod = (name: string, args: Array<unknown>, node: AstNode): unknown => {
   const requireObject = (): Record<string, unknown> => {
     const input = args[0]

packages/codemode/src/stdlib/regexp.ts

@@ -19,6 +19,8 @@ export const escapeRegexHint =
   'To match special characters like ( ) [ ] { } + * ? . literally, escape them with a backslash (e.g. "\\\\(") or test for them with String.includes instead.'
 
 export const toHostRegex = (arg: unknown, method: string, node: AstNode, extraFlags = ""): RegExp => {
+  // Native parity: an undefined pattern behaves as an empty pattern.
+  if (arg === undefined) return new RegExp("", extraFlags)
   if (arg instanceof CodeModeRegExp) return arg.regex
   if (typeof arg === "string") {
     try {

packages/codemode/src/stdlib/value.ts

@@ -61,10 +61,19 @@ export const coerceToString = (value: unknown): string => {
 export const coerceToNumber = (value: unknown): number => {
   if (value instanceof CodeModeDate) return value.time
   if (isCodeModeValue(value)) return Number.NaN
-  return value !== null && typeof value === "object" && !Array.isArray(value) ? Number.NaN : Number(value)
+  // Arrays coerce through our own string coercion: host Number(array) joins with host
+  // ToPrimitive, which throws on the null-prototype objects the interpreter produces.
+  if (Array.isArray(value)) return Number(coerceToString(value))
+  return value !== null && typeof value === "object" ? Number.NaN : Number(value)
 }
 
 export const invokeCoercion = (ref: CoercionFunction, args: Array<unknown>, node: AstNode): unknown => {
+  // Native: Number() is 0 and String() is "", unlike their undefined-argument forms; the
+  // other coercers match native through the undefined-argument path below.
+  if (args.length === 0) {
+    if (ref.name === "Number") return 0
+    if (ref.name === "String") return ""
+  }
   const raw = args[0]
   // Error values are plain SafeObjects; the boundedData path below would strip their brand.
   if (ref.name === "String" && errorBrandName(raw) !== undefined) return coerceToString(raw)
@@ -72,12 +81,16 @@ export const invokeCoercion = (ref: CoercionFunction, args: Array<unknown>, node
     if (ref.name === "Boolean") return true
     if (ref.name === "Number") return coerceToNumber(raw)
     if (ref.name === "String") return coerceToString(raw)
+    if (ref.name === "isFinite") return Number.isFinite(coerceToNumber(raw))
+    if (ref.name === "isNaN") return Number.isNaN(coerceToNumber(raw))
     if (ref.name === "parseInt") return parseInt(coerceToString(raw))
     return parseFloat(coerceToString(raw))
   }
   const value = boundedData(raw, `${ref.name} input`)
   if (ref.name === "Number") return coerceToNumber(value)
   if (ref.name === "Boolean") return Boolean(value)
+  if (ref.name === "isFinite") return Number.isFinite(coerceToNumber(value))
+  if (ref.name === "isNaN") return Number.isNaN(coerceToNumber(value))
   if (ref.name === "parseInt") {
     const radix = args[1]
     if (radix !== undefined && typeof radix !== "number") {