Fix incorrect formats for 0 and rounding very small values

Tisawesomeness · Sep 19, 2023 · 049d05d · 049d05d
1 parent b3c4a57
commit 049d05d
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Showing 4 changed files with 30 additions and 12 deletions.
diff --git a/minecord-bot/src/main/java/com/tisawesomeness/minecord/util/Mth.java b/minecord-bot/src/main/java/com/tisawesomeness/minecord/util/Mth.java
@@ -62,13 +62,16 @@ public static long clamp(long val, long low, long high) {
     }
 
     /**
-     * Computes the largest mantissa {@code n} such that {@code d = x * 10^n} for some {@code 1 <= x < 10}.
-     * <br>In other words, computes the largest exponent {@code n} such that {@code 10^n < d}.
+     * Computes the largest mantissa {@code n} such that {@code d = x * 10^n} for some {@code 1 <= abs(x) < 10}.
+     * <br>In other words, computes the largest exponent {@code n} such that {@code 10^n < abs(d)}.
      * @param d input number
-     * @return {@code n}
+     * @return {@code n}, or 0 if the input is 0
      */
     public static int mantissa(double d) {
-        return (int) Math.floor(StrictMath.log10(d));
+        if (d == 0.0) {
+            return 0;
+        }
+        return (int) Math.floor(StrictMath.log10(Math.abs(d)));
     }
 
     /**

diff --git a/minecord-bot/src/main/java/com/tisawesomeness/minecord/util/type/HumanDecimalFormat.java b/minecord-bot/src/main/java/com/tisawesomeness/minecord/util/type/HumanDecimalFormat.java
@@ -139,9 +139,9 @@ private String addApproxSymbolIfNotExact(NumberFormat format, double d) {
         if (!includeApproximationSymbol || format.getMaximumFractionDigits() > -Double.MIN_EXPONENT) {
             return original;
         }
-        format.setMaximumFractionDigits(format.getMaximumFractionDigits() + 1);
-        String withOneMoreDigit = format.format(d);
-        return original.equals(withOneMoreDigit) ? original : "~" + original;
+        format.setMaximumFractionDigits(-Double.MIN_EXPONENT);
+        String withAllDigits = format.format(d);
+        return original.equals(withAllDigits) ? original : "~" + original;
     }
 
 }
diff --git a/minecord-bot/src/test/java/com/tisawesomeness/minecord/util/MthTest.java b/minecord-bot/src/test/java/com/tisawesomeness/minecord/util/MthTest.java
@@ -38,6 +38,7 @@ public void testClampBad() {
 
     @ParameterizedTest
     @CsvSource({
+            "0.0, 0",
             "0.000001, -6",
             "0.01, -2",
             "0.1, -1",
@@ -46,7 +47,17 @@ public void testClampBad() {
             "1.1, 0",
             "10.0, 1",
             "100.0, 2",
-            "1000000.0, 6"
+            "1000000.0, 6",
+            "-0.0, 0",
+            "-0.000001, -6",
+            "-0.01, -2",
+            "-0.1, -1",
+            "-0.9, -1",
+            "-1.0, 0",
+            "-1.1, 0",
+            "-10.0, 1",
+            "-100.0, 2",
+            "-1000000.0, 6"
     })
     public void testMantissa(double input, int expected) {
         assertThat(Mth.mantissa(input))

diff --git a/minecord-bot/src/test/java/com/tisawesomeness/minecord/util/type/HumanDecimalFormatTest.java b/minecord-bot/src/test/java/com/tisawesomeness/minecord/util/type/HumanDecimalFormatTest.java
@@ -42,7 +42,8 @@ public void testMinMaxExponentError() {
     @CsvSource({
             "123.456, '123.456'",
             "0.1, '0.1'",
-            "2.0, '2'"
+            "2.0, '2'",
+            "0.0, '0'"
     })
     public void testFormat(double input, String expected) {
         HumanDecimalFormat format = HumanDecimalFormat.builder().build();
@@ -56,7 +57,8 @@ public void testFormat(double input, String expected) {
             "-4, 2, 0.000123, '0.000123'",
             "-10, 10, 123000.0, '123000'",
             "-4, 4, 123000.0, '1.23e5'",
-            "-2, 5, 123000.0, '123000'"
+            "-2, 5, 123000.0, '123000'",
+            "0, 0, 0.0, '0'"
     })
     public void testFormatScientific(int minDigits, int maxDigits, double input, String expected) {
         HumanDecimalFormat format = HumanDecimalFormat.builder()
@@ -74,7 +76,8 @@ public void testFormatScientific(int minDigits, int maxDigits, double input, Str
             "0, 0, 123.4567, '123'",
             "3, 5, 123.4567, '123.4567'",
             "5, 5, 123.4567, '123.45670'",
-            "8, 10, 123.4567, '123.45670000'"
+            "8, 10, 123.4567, '123.45670000'",
+            "2, 10, 0.0, '0.00'"
     })
     public void testFormatFractionDigits(int minDigits, int maxDigits, double input, String expected) {
         HumanDecimalFormat format = HumanDecimalFormat.builder()
@@ -100,7 +103,8 @@ public void testFormatGrouping(double input, String expected) {
     @CsvSource({
             "4, 12.3456, '12.3456'",
             "3, 12.3456, '~12.345'",
-            "0, 12.3456, '~12'"
+            "0, 12.3456, '~12'",
+            "1, 0.00001, '~0'"
     })
     public void testFormatApprox(int minDigits, double input, String expected) {
         HumanDecimalFormat format = HumanDecimalFormat.builder()