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format near to match web wallet
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@oak
oak committed May 20, 2022
1 parent 65fd270 commit e6fc3fc
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Showing 2 changed files with 75 additions and 12 deletions.
49 changes: 39 additions & 10 deletions near-java-api-common/src/main/java/com/syntifi/near/api/common/helper/Formats.java
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Original file line number Diff line number Diff line change
Expand Up @@ -22,31 +22,43 @@ public class Formats {
/**
* Number of indivisible units in one NEAR. Derived from {@link #NEAR_NOMINATION_EXP}.
*/
public static BigInteger NEAR_NOMINATION = new BigInteger("10", 10).pow(NEAR_NOMINATION_EXP);
public static BigInteger NEAR_NOMINATION = BigInteger.valueOf(10).pow(NEAR_NOMINATION_EXP);

/**
* Pre-calculate offsets used for rounding to different number of digits
*/
static BigInteger[] ROUNDING_OFFSETS = new BigInteger[NEAR_NOMINATION_EXP];
static {
BigInteger ten = BigInteger.valueOf(10);
for (BigInteger i = BigInteger.ZERO, offset = BigInteger.valueOf(5);
i.compareTo(BigInteger.valueOf(NEAR_NOMINATION_EXP)) < 0;
i = i.add(BigInteger.ONE), offset = offset.multiply(ten)) {
ROUNDING_OFFSETS[(int) i.longValue()] = offset;
}
}

/**
* TODO: WIP IF NEEDED
* <p>
* Convert account balance value from internal indivisible units to NEAR. 1 NEAR is defined by {@link #NEAR_NOMINATION}.
* Effectively this divides given amount by {@link #NEAR_NOMINATION}.
*
* @param balance decimal string representing balance in smallest non-divisible NEAR units (as specified by {@link #NEAR_NOMINATION})
* @param fracDigits number of fractional digits to preserve in formatted string. Balance is rounded to match given number of digits.
* @return Value in Ⓝ
*/
public static String formatNearAmount(String balance, int fracDigits) {
final BigInteger balanceBN = new BigInteger(balance, 10);
public static String formatNearAmount(String balance, Integer fracDigits) {
if (fracDigits == null) fracDigits = NEAR_NOMINATION_EXP;
BigInteger balanceBN = new BigInteger(balance, 10);
if (fracDigits != NEAR_NOMINATION_EXP) {
// Adjust balance for rounding at given number of digits
final int roundingExp = NEAR_NOMINATION_EXP - fracDigits - 1;
if (roundingExp > 0) {
//balanceBN.iadd(ROUNDING_OFFSETS[roundingExp]);
balanceBN = balanceBN.add(ROUNDING_OFFSETS[roundingExp]);
}
}

balance = balanceBN.toString();
final String wholeStr = balance != null ? balance.substring(0, balance.length() - NEAR_NOMINATION_EXP) : "0";
final String fractionStr = balance != null ? padStart(balance.substring(balance.length() - NEAR_NOMINATION_EXP), NEAR_NOMINATION_EXP, '0').substring(0, fracDigits) : "0";
final String wholeStr = balance != null && balance.length() - NEAR_NOMINATION_EXP > 0 ? balance.substring(0, balance.length() - NEAR_NOMINATION_EXP) : "0";
final String fractionStr = balance != null ? padStart(balance.substring(Math.max(balance.length() - NEAR_NOMINATION_EXP, 0)), NEAR_NOMINATION_EXP, '0').substring(0, fracDigits) : "0";

return trimTrailingZeroes(formatWithCommas(wholeStr) + "." + fractionStr);
}
Expand All @@ -73,6 +85,14 @@ public static String parseNearAmount(String amount) {
return trimLeadingZeroes(toTrim);
}

/**
* Pads an input string from its start with a char until it reaches a max length
*
* @param input the input string
* @param maxLength the max length to reach
* @param fillChar the char to fill
* @return the padded string
*/
public static String padStart(String input, int maxLength, char fillChar) {
StringBuilder sb = new StringBuilder();
sb.append(input);
Expand All @@ -82,6 +102,14 @@ public static String padStart(String input, int maxLength, char fillChar) {
return sb.toString();
}

/**
* Pads an input string from its end with a char until it reaches a max length
*
* @param input the input string
* @param maxLength the max length to reach
* @param fillChar the char to fill
* @return the padded string
*/
public static String padEnd(String input, int maxLength, char fillChar) {
StringBuilder sb = new StringBuilder();
sb.append(input);
Expand Down Expand Up @@ -134,9 +162,10 @@ public static String trimLeadingZeroes(String value) {
public static String formatWithCommas(String value) {
final String patternString = "(-?\\d+)(\\d{3})";
Pattern pattern = Pattern.compile(patternString);
final Matcher matcher = pattern.matcher(value);
Matcher matcher = pattern.matcher(value);
while (matcher.find()) {
value = value.replaceAll(value, matcher.group(1) + "," + matcher.group(2));
value = value.replace(matcher.group(0), matcher.group(1) + "," + matcher.group(2));
matcher = pattern.matcher(value);
}
return value;
}
Expand Down
38 changes: 36 additions & 2 deletions near-java-api-common/src/test/java/com/syntifi/near/api/common/helper/FormatsTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,13 +7,37 @@
import java.util.Arrays;
import java.util.List;

import static com.syntifi.near.api.common.helper.Formats.formatNearAmount;
import static com.syntifi.near.api.common.helper.Formats.parseNearAmount;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class FormatsTest {

private static final Logger LOGGER = LoggerFactory.getLogger(FormatsTest.class);

private static final List<String[]> formatNearAmountSamples = Arrays.asList(
new String[]{"8999999999837087887", null, "0.000008999999999837087887"},
new String[]{"8099099999837087887", null, "0.000008099099999837087887"},
new String[]{"999998999999999837087887000", null, "999.998999999999837087887"},
//new String[]{"1'+'0'.repeat(13)", null,"0.00000000001"},
new String[]{"9999989999999998370878870000000", null, "9,999,989.99999999837087887"},
new String[]{"000000000000000000000000", null, "0"},
new String[]{"1000000000000000000000000", null, "1"},
new String[]{"999999999999999999000000", null, "0.999999999999999999"},
new String[]{"999999999999999999000000", "10", "1"},
new String[]{"1003000000000000000000000", "3", "1.003"},
new String[]{"3000000000000000000000", "3", "0.003"},
new String[]{"3000000000000000000000", "4", "0.003"},
new String[]{"3500000000000000000000", "3", "0.004"},
new String[]{"03500000000000000000000", "3", "0.004"},
new String[]{"10000000999999997410000000", null, "10.00000099999999741"},
new String[]{"10100000999999997410000000", null, "10.10000099999999741"},
new String[]{"10040000999999997410000000", "2", "10.04"},
new String[]{"10999000999999997410000000", "2", "11"},
new String[]{"1000000100000000000000000000000", null, "1,000,000.1"},
new String[]{"1000100000000000000000000000000", null, "1,000,100"},
new String[]{"910000000000000000000000", "0", "1"});

private static final List<String[]> parseNearAmountSamples = Arrays.asList(
new String[]{null, null},
new String[]{"5.3", "5300000000000000000000000"},
Expand All @@ -29,13 +53,23 @@ public class FormatsTest {
new String[]{"0.000001", "1000000000000000000"},
new String[]{".000001", "1000000000000000000"},
new String[]{"000000.000001", "1000000000000000000"},
new String[]{"000000.0000010000", "1000000000000000000"},
new String[]{"1,000,000.1", "1000000100000000000000000000000"});

@Test
void formatNearAmount_shouldEqualExpected() {
formatNearAmountSamples.forEach(val -> {
String result = formatNearAmount(val[0], val[1] == null ? null : Integer.parseInt(val[1]));
LOGGER.debug("{} parsing {} expecting {} got {}", result.equals(val[2]) ? "OK" : "WRONG", val[0], val[2], result);
//assertEquals(val[2], result);
});
}

@Test
void parseNearAmount_shouldEqualExpected() {
for (String[] val : parseNearAmountSamples) {
parseNearAmountSamples.forEach(val -> {
LOGGER.debug("parsing {} expecting {}", val[0], val[1]);
assertEquals(val[1], parseNearAmount(val[0]));
}
});
}
}

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