Function TestNewFromFloatWithExponent

decimal_test.go:407–475

(t *testing.T)

}

func TestNewFromFloatWithExponent(t *testing.T) {
	type Inp struct {
		float float64
		exp   int32
	}
	// some tests are taken from here https://www.cockroachlabs.com/blog/rounding-implementations-in-go/
	tests := map[Inp]string{
		Inp{123.4, -3}:                 "123.4",
		Inp{123.4, -1}:                 "123.4",
		Inp{123.412345, 1}:             "120",
		Inp{123.412345, 0}:             "123",
		Inp{123.412345, -5}:            "123.41235",
		Inp{123.412345, -6}:            "123.412345",
		Inp{123.412345, -7}:            "123.412345",
		Inp{123.412345, -28}:           "123.4123450000000019599610823207",
		Inp{1230000000, 3}:             "1230000000",
		Inp{123.9999999999999999, -7}:  "124",
		Inp{123.8989898999999999, -7}:  "123.8989899",
		Inp{0.49999999999999994, 0}:    "0",
		Inp{0.5, 0}:                    "1",
		Inp{0., -1000}:                 "0",
		Inp{0.5000000000000001, 0}:     "1",
		Inp{1.390671161567e-309, 0}:    "0",
		Inp{4.503599627370497e+15, 0}:  "4503599627370497",
		Inp{4.503599627370497e+60, 0}:  "4503599627370497110902645731364739935039854989106233267453952",
		Inp{4.503599627370497e+60, 1}:  "4503599627370497110902645731364739935039854989106233267453950",
		Inp{4.503599627370497e+60, -1}: "4503599627370497110902645731364739935039854989106233267453952",
		Inp{50, 2}:                     "100",
		Inp{49, 2}:                     "0",
		Inp{50, 3}:                     "0",
		// subnormals
		Inp{1.390671161567e-309, -2000}: "0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001390671161567000864431395448332752540137009987788957394095829635554502771758698872408926974382819387852542087331897381878220271350970912568035007740861074263206736245957501456549756342151614772544950978154339064833880234531754156635411349342950306987480369774780312897442981323940546749863054846093718407237782253156822124910364044261653195961209878120072488178603782495270845071470243842997312255994555557251870400944414666445871039673491570643357351279578519863428540219295076767898526278029257129758694673164251056158277568765100904638511604478844087596428177947970563689475826736810456067108202083804368114484417399279328807983736233036662284338182105684628835292230438999173947056675615385756827890872955322265625",
		Inp{1.390671161567e-309, -862}:  "0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000013906711615670008644313954483327525401370099877889573940958296355545027717586988724089269743828193878525420873318973818782202713509709125680350077408610742632067362459575014565497563421516147725449509781543390648338802345317541566354113493429503069874803697747803128974429813239405467498630548460937184072377822531568221249103640442616531959612098781200724881786037824952708450714702438429973122559945555572518704009444146664458710396734915706433573512795785198634285402192950767678985262780292571297586946731642510561582775687651009046385116044788440876",
		Inp{1.390671161567e-309, -863}:  "0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000013906711615670008644313954483327525401370099877889573940958296355545027717586988724089269743828193878525420873318973818782202713509709125680350077408610742632067362459575014565497563421516147725449509781543390648338802345317541566354113493429503069874803697747803128974429813239405467498630548460937184072377822531568221249103640442616531959612098781200724881786037824952708450714702438429973122559945555572518704009444146664458710396734915706433573512795785198634285402192950767678985262780292571297586946731642510561582775687651009046385116044788440876",
	}

	// add negatives
	for p, s := range tests {
		if p.float > 0 {
			if s != "0" {
				tests[Inp{-p.float, p.exp}] = "-" + s
			} else {
				tests[Inp{-p.float, p.exp}] = "0"
			}
		}
	}

	for input, s := range tests {
		d := NewFromFloatWithExponent(input.float, input.exp)
		if d.String() != s {
			t.Errorf("expected %s, got %s (%s, %d)",
				s, d.String(),
				d.value.String(), d.exp)
		}
	}

	shouldPanicOn := []float64{
		math.NaN(),