[ErrorProne] Enable BigDecimalEquals check and fix violations (#38193)

* enable BigDecimalEquals

* fix violations

Author: stankiewicz

buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy

@@ -1533,7 +1533,6 @@ class BeamModulePlugin implements Plugin<Project> {
             // TODO(https://github.com/apache/beam/issues/20955): Enable errorprone checks
             "AutoValueImmutableFields",
             "AutoValueSubclassLeaked",
-            "BigDecimalEquals",
             "ComparableType",
             "DoNotMockAutoValue",
             "EmptyBlockTag",

sdks/java/core/src/main/java/org/apache/beam/sdk/util/RowJsonValueExtractors.java

@@ -140,8 +140,9 @@ static ValueExtractor<Double> doubleValueExtractor() {
                     // Or a decimal number which allows lossless conversion to float
                     || (jsonNode.isFloatingPointNumber()
                         && jsonNode
-                            .decimalValue()
-                            .equals(BigDecimal.valueOf(jsonNode.doubleValue()))))
+                                .decimalValue()
+                                .compareTo(BigDecimal.valueOf(jsonNode.doubleValue()))
+                            == 0))
         .build();
   }
 

sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/transform/agg/CovarianceFn.java

@@ -125,7 +125,7 @@ private BigDecimal getCovariance(CovarianceAccumulator covariance) {
         this.isSample ? covariance.count().subtract(BigDecimal.ONE) : covariance.count();
 
     // Avoid ArithmeticException: Division is undefined when adjustedCount is 0
-    if (adjustedCount.equals(BigDecimal.ZERO)) {
+    if (adjustedCount.compareTo(BigDecimal.ZERO) == 0) {
       return BigDecimal.ZERO;
     }
 

sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/transform/agg/VarianceFn.java

@@ -142,7 +142,7 @@ private BigDecimal getVariance(VarianceAccumulator variance) {
         this.isSample ? variance.count().subtract(BigDecimal.ONE) : variance.count();
 
     // Avoid ArithmeticException: Division is undefined when adjustedCount is 0
-    if (adjustedCount.equals(BigDecimal.ZERO)) {
+    if (adjustedCount.compareTo(BigDecimal.ZERO) == 0) {
       return BigDecimal.ZERO;
     }