fix: resolve float decimal precision issue on round() function. (#160)

* fix: update @testing-library/react to use create root * fix: resolve float decimal precision issue on round() function. * Simplify round() function. Remove managing the negative sign separately. Co-authored-by: Norbert Nader <Norbert.Nader@gmail.com>
awslabs · Jul 14, 2022 · d95f69e · d95f69e
1 parent 8523409
commit d95f69e
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Showing 2 changed files with 40 additions and 36 deletions.
diff --git a/packages/core/src/common/number.spec.ts b/packages/core/src/common/number.spec.ts
@@ -42,39 +42,40 @@ describe.each`
 });
 
 describe.each`
-  value             | preciseValue
-  ${0.00345678}     | ${0.003457}
-  ${0.02345678}     | ${0.02346}
-  ${1.02345678}     | ${1.0235}
-  ${10.02345678}    | ${10.0235}
-  ${1}              | ${1}
-  ${1.0}            | ${1}
-  ${1.2}            | ${1.2}
-  ${1.29}           | ${1.29}
-  ${1.129}          | ${1.129}
-  ${1000.1234}      | ${1000.1234}
-  ${1000.12345}     | ${1000.1235}
-  ${1000.02345}     | ${1000.0235}
-  ${1000.003456}    | ${1000.0035}
-  ${1000.000056}    | ${1000.0001}
-  ${891289.000056}  | ${891289.0001}
-  ${-0.00345678}    | ${-0.003457}
-  ${-0.02345678}    | ${-0.02346}
-  ${-1.0}           | ${-1}
-  ${-1.2}           | ${-1.2}
-  ${-1.29}          | ${-1.29}
-  ${-1.129}         | ${-1.129}
-  ${-1000.1234}     | ${-1000.1234}
-  ${-1000.12345}    | ${-1000.1235}
-  ${-1000.02345}    | ${-1000.0235}
-  ${-1000.003456}   | ${-1000.0035}
-  ${-1000.000056}   | ${-1000.0001}
-  ${-891289.000056} | ${-891289.0001}
-  ${NaN}            | ${NaN}
-  ${Infinity}       | ${Infinity}
-  ${-Infinity}      | ${-Infinity}
-  ${-0}             | ${0}
-  ${0.0}            | ${0}
+  value                 | preciseValue
+  ${0.00345678}         | ${0.003457}
+  ${0.02345678}         | ${0.02346}
+  ${1.02345678}         | ${1.0235}
+  ${10.02345678}        | ${10.0235}
+  ${1}                  | ${1}
+  ${1.0}                | ${1}
+  ${1.2}                | ${1.2}
+  ${1.29}               | ${1.29}
+  ${1.129}              | ${1.129}
+  ${1000.1234}          | ${1000.1234}
+  ${1000.12345}         | ${1000.1235}
+  ${1000.02345}         | ${1000.0235}
+  ${1000.003456}        | ${1000.0035}
+  ${1000.000056}        | ${1000.0001}
+  ${891289.000056}      | ${891289.0001}
+  ${28.910800000000002} | ${28.9108}
+  ${-0.00345678}        | ${-0.003457}
+  ${-0.02345678}        | ${-0.02346}
+  ${-1.0}               | ${-1}
+  ${-1.2}               | ${-1.2}
+  ${-1.29}              | ${-1.29}
+  ${-1.129}             | ${-1.129}
+  ${-1000.1234}         | ${-1000.1234}
+  ${-1000.12345}        | ${-1000.1235}
+  ${-1000.02345}        | ${-1000.0235}
+  ${-1000.003456}       | ${-1000.0035}
+  ${-1000.000056}       | ${-1000.0001}
+  ${-891289.000056}     | ${-891289.0001}
+  ${NaN}                | ${NaN}
+  ${Infinity}           | ${Infinity}
+  ${-Infinity}          | ${-Infinity}
+  ${-0}                 | ${0}
+  ${0.0}                | ${0}
 `('rounds number', ({ value, preciseValue }) => {
   test(`round(${value}) => ${preciseValue}`, () => {
     expect(round(value)).toBe(preciseValue);

diff --git a/packages/core/src/common/number.ts b/packages/core/src/common/number.ts
@@ -14,13 +14,16 @@ export const round = (num: number): number => {
     return num;
   }
 
-  if (Math.abs(num) < 1) {
+  const absoluteValue = Math.abs(num);
+  if (absoluteValue < 1) {
     return Number(num.toPrecision(MAX_PRECISION));
   }
 
   const integer = Math.trunc(num);
-  const decimal = num - integer;
-  return integer + Number(decimal.toFixed(MAX_PRECISION));
+  // in case of negative number, we need to remove the first 3 characters from decimal string eg. -0.123 => 123
+  const decimal = (num - integer).toFixed(MAX_PRECISION).substring(num !== absoluteValue ? 3 : 2);
+
+  return Number(`${integer}.${decimal}`);
 };
 
 /**