`pkg/random`¶

Convenience helpers for building fixtures, tokens, and fuzz data. Functions span deterministic math/rand utilities and crypto-safe password generation.

Quick Start¶

import (
    "math/rand"
    "time"
    mangorand "github.com/bitstep-ie/mango-go/pkg/random"
)

func init() {
    rand.Seed(time.Now().UnixNano()) // seed math/rand once per process
}

func example() {
    promo := mangorand.String(8)
    orderID := mangorand.Number[int](1000, 9999)
    mustRun := mangorand.Bool()
    secret := mangorand.Password(24, mangorand.PasswordOptions{
        Letters: true,
        Digits:  true,
        Symbols: true,
        Exclude: "O0l1",
    })
    _ = []any{promo, orderID, mustRun, secret}
}

API Highlights¶

Numbers & Booleans¶

Number[T Num](min, max T) – inclusive range for ints/uints, [min,max) for floats. Automatically swaps min/max.
Sign() – returns +1 or -1.
Bool() – coin flip.
Choice(slice []T) – pick a random element, panics on empty slice.

Bytes & Strings¶

Byte() – cryptographically secure random byte.
String(n) – alphanumeric (upper+lowercase, digits).
Alpha(n) / Numeric(n) – letters-only or digits-only.
FromCharset(n, charset) – supply your own rune set.

Passwords¶

pw := mangorand.Password(16, mangorand.PasswordOptions{
    Letters: true,
    Digits:  true,
    Symbols: false,
})

Options allow mixing letters, digits, symbols, plus excluding ambiguous characters. Generation uses crypto/rand so the output is safe for access tokens and human passwords. Panics if the resulting charset would be empty.

Time Helpers¶

Date(min, max time.Time) – inclusive random timestamp.
Duration(min, max time.Duration) – inclusive random duration.

Both helpers swap arguments when min > max, making it easy to mock “recent” or “soon” values without extra branching.

Tips¶

Only the functions under “Numbers & Booleans” rely on math/rand; seed it once during startup for non-deterministic sequences.
Choice and Password panic when misused; wrap them in helper functions if you need error returns instead.
Combine PasswordOptions{Symbols: true} with testutils.ContainsAllRunes to assert generated strings hit every required character class in tests.

pkg/random¶