Merge pull request #35 from xiaosu12138/fix-negative

feat: 修复负数四舍五入有误的问题
nefe · May 23, 2021 · b1bde33 · b1bde33
2 parents 44f82b8 + 04b4dc5
commit b1bde33
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diff --git a/src/index.ts b/src/index.ts
@@ -106,7 +106,11 @@ function divide(num1: numType, num2: numType, ...others: numType[]): number {
  */
 function round(num: numType, ratio: number): number {
   const base = Math.pow(10, ratio);
-  return divide(Math.round(times(num, base)), base);
+  let result = divide(Math.round(Math.abs(times(num, base))), base);
+  if (num < 0 && result !== 0) {
+    result = times(result, -1);
+  }
+  return result;
 }
 
 let _boundaryCheckingState = true;

diff --git a/test/index.test.ts b/test/index.test.ts
@@ -248,4 +248,17 @@ test('NP.round can do round operation', (t) => {
   t.true(NP.round('1.2345e3', 3) === 1234.5);
   t.true(NP.round('1.2344e3', 3) === 1234.4);
   t.true(NP.round('1e3', 1) === 1000);
+
+  t.true(NP.round('-0.125', 2) === -0.13);
+  t.true(NP.round('-0.001', 2) === 0.00);
+  t.true(NP.round('-0.005', 2) === -0.01);
+  t.true(NP.round('0.125', 2) === 0.13);
+  t.true(NP.round('0.001', 2) === 0.00);
+  t.true(NP.round('0.005', 2) === 0.01);
+  t.true(NP.round(-0.125, 2) === -0.13);
+  t.true(NP.round(-0.001, 2) === 0.00);
+  t.true(NP.round(-0.005, 2) === -0.01);
+  t.true(NP.round(0.125, 2) === 0.13);
+  t.true(NP.round(0.001, 2) === 0.00);
+  t.true(NP.round(0.005, 2) === 0.01);
 });