supportive-is

Documents the five collection and shape predicates — `isObject`, `isPlainObject`, `Is.array`, `isIterable`, and `isEmpty` — including the falsy-return pattern and known bugs. TRIGGER when: code imports `isObject`, `isPlainObject`, `isIterable`, `isEmpty`, or uses `Is.array` from `@mongez/supportive-is`; user asks "how do I check if an object is empty / a plain object / iterable", "why does isObject return null instead of false", or "how do I detect a class instance vs literal object"; typical import is `import { isEmpty, isPlainObject } from "@mongez/supportive-is"` (or legacy `import Is from "@mongez/supportive-is"; Is.empty(x)`). SKIP: general-purpose array/object utilities (`get`, `set`, `clone`, `pluck`, `groupBy`) — use `mongez-reinforcements-*` skills, since this package is purely shape/type PREDICATES not transformations; schema validation via `zod`/`valibot`; native `Array.isArray`/`typeof` checks without this package imported.

Documents the browser and device-environment predicates — `isMobile`, `isMac`, `isDesktop`, `isBrowser`, `isChrome`, `isFirefox`, `isSafari`, `isOpera`, `isIE`, and `isEdge` — including SSR safety rules and known bugs. TRIGGER when: code imports `isMobile`, `isMac`, `isDesktop`, `isBrowser`, `isChrome`, `isFirefox`, `isSafari`, `isOpera`, `isIE`, or `isEdge` from `@mongez/supportive-is`; user asks "how do I detect mobile / iOS / Android", "Cmd vs Ctrl on Mac", "browser sniff for Safari/Chrome/Firefox", or "is this code running in browser vs SSR"; typical import is `import { isMobile, isMac } from "@mongez/supportive-is"` (or `Is.mobile.android()` via the legacy default export — note this package commonly exposes methods through the `Is` object too). SKIP: server-side user-agent parsing from request headers — use a dedicated UA parser library on `request.headers.get("user-agent")`; React-Native or Capacitor device-info APIs; CSS media queries for responsive layout; feature-detection beyond what these vendor pr

High-level introduction to `@mongez/supportive-is` — what it is, how to install and import it, its mental model, and where its scope ends. TRIGGER when: code imports anything from `@mongez/supportive-is` (named export OR default `Is`); user asks "what does @mongez/supportive-is do", "how do I install or import supportive-is", "named exports vs the Is namespace", or "which predicates does this package give me"; typical import is `import { isEmpty } from "@mongez/supportive-is"` for tree-shaking, or legacy `import Is from "@mongez/supportive-is"; Is.empty(x)` — note this package commonly exports a default `Is` object with methods, not many top-level functions. SKIP: deep-dive on a specific predicate group (use the category-specific `mongez-supportive-is-*` skill — primitives, collections, formats, misc, environment); `@mongez/reinforcements` general object/string/array utilities which are transformations not predicates; schema validation via `zod`/`valibot`.

Documents the six primitive and numeric predicates — `isString`, `isNumeric`, `isInt`, `isFloat`, `isPrimitive`, and `isScalar` — including their semantics, edge cases, and known bugs. TRIGGER when: code imports `isString`, `isNumeric`, `isInt`, `isFloat`, `isPrimitive`, or `isScalar` from `@mongez/supportive-is`; user asks "how do I check string / number / int / float", "detect a numeric string like '12'", "difference between isPrimitive and isScalar", or "type-narrow a string in TS"; typical import is `import { isString, isNumeric } from "@mongez/supportive-is"` (or `Is.string(x)` / `Is.numeric(x)` via the legacy default `Is` namespace). SKIP: native `typeof v === "string"` or `Number.isInteger(v)` checks where you don't need this package — those are correct and avoid this package's known `isInt`/`isFloat` negative-number bugs; `@mongez/reinforcements` for string/number transformations (not predicates); schema validators.

Idiomatic composition patterns for `@mongez/supportive-is` predicates, covering form validation, deep merge, empty filtering, mobile-aware UI, keyboard shortcuts, URL coercion, polymorphic APIs, and TypeScript type narrowing. TRIGGER when: code combines multiple `@mongez/supportive-is` imports (e.g. `isEmpty` + `isEmail` + `isUrl` for forms, or `isPlainObject` for deep merge); user asks "how do I validate a form with supportive-is", "deep merge that respects class instances", "filter out empty values", "Cmd vs Ctrl shortcut", "polymorphic string-or-regex argument", or "TS type narrowing with isString"; typical import is `import { isEmpty, isEmail, isUrl } from "@mongez/supportive-is"` — combining several predicates in one module. SKIP: single-predicate questions — use the category-specific skill (`mongez-supportive-is-primitives`/`-collections`/`-formats`/`-misc`/`-environment`); React-specific form-state libraries like `react-hook-form` or `formik`; `@mongez/reinforcements` recipes for object/array transform

Documents the five string-format predicates — `isRegex`, `isValidId`, `isJson`, `isUrl`, and `isEmail` — including their rules, limitations, and known bugs. TRIGGER when: code imports `isRegex`, `isValidId`, `isJson`, `isUrl`, or `isEmail` from `@mongez/supportive-is`; user asks "how do I validate URL / email / JSON / HTML id", "check if string is a regex or pattern", or "tell if a value looks like valid JSON"; typical import is `import { isUrl, isEmail } from "@mongez/supportive-is"` (or `Is.url(x)` / `Is.email(x)` via the legacy default `Is` namespace). SKIP: trustworthy validation for auth, redirects, or stored data — use `zod`, `valibot`, or RFC-grade libraries instead since these are convenience filters not security gates; schema-based form validation libraries; `@mongez/reinforcements` for general string transforms, not predicates.

Documents the five object-kind predicates — `isPromise`, `isDate`, `isGenerator`, `isFormElement`, and `isFormData` — including constructor-name semantics and known bugs. TRIGGER when: code imports `isPromise`, `isDate`, `isGenerator`, `isFormElement`, or `isFormData` from `@mongez/supportive-is`; user asks "how do I detect a Promise / Date / generator / form element / FormData", "is this thing a thenable", or "check Date vs string vs number"; typical import is `import { isPromise, isDate } from "@mongez/supportive-is"` (or `Is.promise(x)` / `Is.date(x)` / `Is.form(x)` via the legacy default `Is` namespace). SKIP: thenable-protocol checks for non-native Promises (these are constructor-name checks that miss subclasses — use `value instanceof Promise` instead); date math or arithmetic — use `dayjs`/`date-fns`/`Temporal`, this only tells you "is it a Date instance"; `@mongez/reinforcements` general utilities.