From e1265c819870c6a4d6763529e9fbd2d70c722fe0 Mon Sep 17 00:00:00 2001 From: Kenta Murata Date: Fri, 22 Jan 2021 12:03:37 +0900 Subject: [ruby/bigdecimal] Use larger precision in divide for irrational or recurring results Just in case for irrational or recurring results, the precision of the quotient is set to at least more than 2*Float::DIG plus alpha. [Bug #13754] [Fix GH-94] https://github.com/ruby/bigdecimal/commit/99442c75d3 --- test/bigdecimal/test_bigdecimal.rb | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'test/bigdecimal') diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb index 1e6c59535f..66b58aa124 100644 --- a/test/bigdecimal/test_bigdecimal.rb +++ b/test/bigdecimal/test_bigdecimal.rb @@ -953,9 +953,13 @@ class TestBigDecimal < Test::Unit::TestCase assert_equal(2, BigDecimal("2") / 1) assert_equal(-2, BigDecimal("2") / -1) - assert_equal(BigDecimal('1486.868686869'), BigDecimal('1472.0') / BigDecimal('0.99'), '[ruby-core:59365] [#9316]') + assert_equal(BigDecimal('1486.868686869'), + (BigDecimal('1472.0') / BigDecimal('0.99')).round(9), + '[ruby-core:59365] [#9316]') - assert_equal(4.124045235, BigDecimal('0.9932') / (700 * BigDecimal('0.344045') / BigDecimal('1000.0')), '[#9305]') + assert_in_delta(4.124045235, + (BigDecimal('0.9932') / (700 * BigDecimal('0.344045') / BigDecimal('1000.0'))).round(9, half: :up), + 10**Float::MIN_10_EXP, '[#9305]') BigDecimal.mode(BigDecimal::EXCEPTION_INFINITY, false) assert_positive_zero(BigDecimal("1.0") / BigDecimal("Infinity")) @@ -969,6 +973,15 @@ class TestBigDecimal < Test::Unit::TestCase assert_raise_with_message(FloatDomainError, "Computation results in '-Infinity'") { BigDecimal("-1") / 0 } end + def test_dev_precision + bug13754 = '[ruby-core:82107] [Bug #13754]' + a = BigDecimal('101') + b = BigDecimal('0.9163472602589686') + c = a/b + assert(c.precision > b.precision, + "(101/0.9163472602589686).precision >= (0.9163472602589686).precision #{bug13754}") + end + def test_div_with_float assert_kind_of(BigDecimal, BigDecimal("3") / 1.5) assert_equal(BigDecimal("0.5"), BigDecimal(1) / 2.0) -- cgit v1.2.3