codekingpro/portable-devtools

1// Copyright 2024 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4 5package rand_test6 7import (8	"crypto/rand"9	"fmt"10	"testing"11)12 13func TestText(t *testing.T) {14	set := make(map[string]struct{}) // hold every string produced15	var indexSet [26]map[rune]int    // hold every char produced at every position16	for i := range indexSet {17		indexSet[i] = make(map[rune]int)18	}19 20	// not getting a char in a position: (31/32)¹⁰⁰⁰ = 1.6e-1421	// test completion within 1000 rounds: (1-(31/32)¹⁰⁰⁰)²⁶ = 0.999999999999622	// empirically, this should complete within 400 rounds = 0.99992123	rounds := 100024	var done bool25	for range rounds {26		s := rand.Text()27		if len(s) != 26 {28			t.Errorf("len(Text()) = %d, want = 26", len(s))29		}30		for i, r := range s {31			if ('A' > r || r > 'Z') && ('2' > r || r > '7') {32				t.Errorf("Text()[%d] = %v, outside of base32 alphabet", i, r)33			}34		}35		if _, ok := set[s]; ok {36			t.Errorf("Text() = %s, duplicate of previously produced string", s)37		}38		set[s] = struct{}{}39 40		done = true41		for i, r := range s {42			indexSet[i][r]++43			if len(indexSet[i]) != 32 {44				done = false45			}46		}47		if done {48			break49		}50	}51	if !done {52		t.Errorf("failed to produce every char at every index after %d rounds", rounds)53		indexSetTable(t, indexSet)54	}55}56 57func indexSetTable(t *testing.T, indexSet [26]map[rune]int) {58	alphabet := "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"59	line := "   "60	for _, r := range alphabet {61		line += fmt.Sprintf(" %3s", string(r))62	}63	t.Log(line)64	for i, set := range indexSet {65		line = fmt.Sprintf("%2d:", i)66		for _, r := range alphabet {67			line += fmt.Sprintf(" %3d", set[r])68		}69		t.Log(line)70	}71}72