Add MatchRegistry for custom match implementations. (#390)

* Replace MatchType in favor of MatchRegistry * Add conditionValue to Match#match interface. * Remove the abstract AttributeMatch class. * Remove ExactNumberMatch class. * Add NumberComparator for standardizing Number comparisons * Refactor Semantic Versioning to use static convenience method Incorporating a public MatchRegistry will allow consumers to provide their own implementations of the Match interface.

Author: Mike Davis

core-api/src/main/java/com/optimizely/ab/config/audience/UserAttribute.java

@@ -20,10 +20,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.optimizely.ab.config.ProjectConfig;
-import com.optimizely.ab.config.audience.match.Match;
-import com.optimizely.ab.config.audience.match.MatchType;
-import com.optimizely.ab.config.audience.match.UnexpectedValueTypeException;
-import com.optimizely.ab.config.audience.match.UnknownMatchTypeException;
+import com.optimizely.ab.config.audience.match.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -87,35 +84,36 @@ public Boolean evaluate(ProjectConfig config, Map<String, ?> attributes) {
  }
  // check user attribute value is equal
  try {
- Match matchType = MatchType.getMatchType(match, value).getMatcher();
- Boolean result = matchType.eval(userAttributeValue);
-
+ Match matcher = MatchRegistry.getMatch(match);
+ Boolean result = matcher.eval(value, userAttributeValue);
  if (result == null) {
- if (!attributes.containsKey(name)) {
- //Missing attribute value
- logger.debug("Audience condition \"{}\" evaluated to UNKNOWN because no value was passed for user attribute \"{}\"", this, name);
+ throw new UnknownValueTypeException();
+ }
+
+ return result;
+ } catch(UnknownValueTypeException e) {
+ if (!attributes.containsKey(name)) {
+ //Missing attribute value
+ logger.debug("Audience condition \"{}\" evaluated to UNKNOWN because no value was passed for user attribute \"{}\"", this, name);
+ } else {
+ //if attribute value is not valid
+ if (userAttributeValue != null) {
+ logger.warn(
+ "Audience condition \"{}\" evaluated to UNKNOWN because a value of type \"{}\" was passed for user attribute \"{}\"",
+ this,
+ userAttributeValue.getClass().getCanonicalName(),
+ name);
  } else {
- //if attribute value is not valid
- if (userAttributeValue != null) {
- logger.warn(
- "Audience condition \"{}\" evaluated to UNKNOWN because a value of type \"{}\" was passed for user attribute \"{}\"",
- this,
- userAttributeValue.getClass().getCanonicalName(),
- name);
- } else {
- logger.debug(
- "Audience condition \"{}\" evaluated to UNKNOWN because a null value was passed for user attribute \"{}\"",
- this,
- name);
- }
+ logger.debug(
+ "Audience condition \"{}\" evaluated to UNKNOWN because a null value was passed for user attribute \"{}\"",
+ this,
+ name);
  }
  }
- return result;
- } catch (UnknownMatchTypeException | UnexpectedValueTypeException ex) {
- logger.warn("Audience condition \"{}\" " + ex.getMessage(),
- this);
- } catch (NullPointerException np) {
- logger.error("attribute or value null for match {}", match != null ? match : "legacy condition", np);
+ } catch (UnknownMatchTypeException | UnexpectedValueTypeException e) {
+ logger.warn("Audience condition \"{}\" " + e.getMessage(), this);
+ } catch (NullPointerException e) {
+ logger.error("attribute or value null for match {}", match != null ? match : "legacy condition", e);
  }
  return null;
  }

core-api/src/main/java/com/optimizely/ab/config/audience/match/DefaultMatchForLegacyAttributes.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,17 +21,16 @@
 /**
  * This is a temporary class. It mimics the current behaviour for
  * legacy custom attributes. This will be dropped for ExactMatch and the unit tests need to be fixed.
- * @param <T>
  */
-class DefaultMatchForLegacyAttributes<T> extends AttributeMatch<T> {
- T value;
-
- protected DefaultMatchForLegacyAttributes(T value) {
- this.value = value;
- }
-
+class DefaultMatchForLegacyAttributes implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- return value.equals(castToValueType(attributeValue, value));
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnexpectedValueTypeException {
+ if (!(conditionValue instanceof String)) {
+ throw new UnexpectedValueTypeException();
+ }
+ if (attributeValue == null) {
+ return false;
+ }
+ return conditionValue.toString().equals(attributeValue.toString());
  }
 }

core-api/src/main/java/com/optimizely/ab/config/audience/match/ExactMatch.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,18 +18,31 @@
 
 import javax.annotation.Nullable;
 
-class ExactMatch<T> extends AttributeMatch<T> {
- T value;
-
- protected ExactMatch(T value) {
- this.value = value;
- }
+import static com.optimizely.ab.internal.AttributesUtil.isValidNumber;
 
+/**
+ * ExactMatch supports matching Numbers, Strings and Booleans. Numbers are first converted to doubles
+ * before the comparison is evaluated. See {@link NumberComparator} Strings and Booleans are evaulated
+ * via the Object equals method.
+ */
+class ExactMatch implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- T converted = castToValueType(attributeValue, value);
- if (value != null && converted == null) return null;
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnexpectedValueTypeException {
+ if (isValidNumber(attributeValue)) {
+ if (isValidNumber(conditionValue)) {
+ return NumberComparator.compareUnsafe(attributeValue, conditionValue) == 0;
+ }
+ return null;
+ }
+
+ if (!(conditionValue instanceof String || conditionValue instanceof Boolean)) {
+ throw new UnexpectedValueTypeException();
+ }
+
+ if (attributeValue == null || attributeValue.getClass() != conditionValue.getClass()) {
+ return null;
+ }
 
- return value == null ? attributeValue == null : value.equals(converted);
+ return conditionValue.equals(attributeValue);
  }
 }

core-api/src/main/java/com/optimizely/ab/config/audience/match/ExactNumberMatch.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,20 +16,14 @@
  */
 package com.optimizely.ab.config.audience.match;
 
-import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
-
 import javax.annotation.Nullable;
 
+/**
+ * ExistsMatch checks that the attribute value is NOT null.
+ */
 class ExistsMatch implements Match {
- @SuppressFBWarnings("URF_UNREAD_FIELD")
- Object value;
-
- protected ExistsMatch(Object value) {
- this.value = value;
- }
-
  @Nullable
- public Boolean eval(Object attributeValue) {
+ public Boolean eval(Object conditionValue, Object attributeValue) {
  return attributeValue != null;
  }
 }

core-api/src/main/java/com/optimizely/ab/config/audience/match/ExistsMatch.java

@@ -18,24 +18,12 @@
 
 import javax.annotation.Nullable;
 
-import static com.optimizely.ab.internal.AttributesUtil.isValidNumber;
-
-class GEMatch extends AttributeMatch<Number> {
- Number value;
-
- protected GEMatch(Number value) {
- this.value = value;
- }
-
+/**
+ * GEMatch performs a "greater than or equal to" number comparison via {@link NumberComparator}.
+ */
+class GEMatch implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- try {
- if(isValidNumber(attributeValue)) {
- return castToValueType(attributeValue, value).doubleValue() >= value.doubleValue();
- }
- } catch (Exception e) {
- return null;
- }
- return null;
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnknownValueTypeException {
+ return NumberComparator.compare(attributeValue, conditionValue) >= 0;
  }
 }

core-api/src/main/java/com/optimizely/ab/config/audience/match/GEMatch.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,24 +18,12 @@
 
 import javax.annotation.Nullable;
 
-import static com.optimizely.ab.internal.AttributesUtil.isValidNumber;
-
-class GTMatch extends AttributeMatch<Number> {
- Number value;
-
- protected GTMatch(Number value) {
- this.value = value;
- }
-
+/**
+ * GTMatch performs a "greater than" number comparison via {@link NumberComparator}.
+ */
+class GTMatch implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- try {
- if(isValidNumber(attributeValue)) {
- return castToValueType(attributeValue, value).doubleValue() > value.doubleValue();
- }
- } catch (Exception e) {
- return null;
- }
- return null;
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnknownValueTypeException {
+ return NumberComparator.compare(attributeValue, conditionValue) > 0;
  }
 }

core-api/src/main/java/com/optimizely/ab/config/audience/match/GTMatch.java

@@ -18,25 +18,13 @@
 
 import javax.annotation.Nullable;
 
-import static com.optimizely.ab.internal.AttributesUtil.isValidNumber;
-
-class LEMatch extends AttributeMatch<Number> {
- Number value;
-
- protected LEMatch(Number value) {
- this.value = value;
- }
-
+/**
+ * GEMatch performs a "less than or equal to" number comparison via {@link NumberComparator}.
+ */
+class LEMatch implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- try {
- if(isValidNumber(attributeValue)) {
- return castToValueType(attributeValue, value).doubleValue() <= value.doubleValue();
- }
- } catch (Exception e) {
- return null;
- }
- return null;
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnknownValueTypeException {
+ return NumberComparator.compare(attributeValue, conditionValue) <= 0;
  }
 }
 

core-api/src/main/java/com/optimizely/ab/config/audience/match/LEMatch.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,25 +18,12 @@
 
 import javax.annotation.Nullable;
 
-import static com.optimizely.ab.internal.AttributesUtil.isValidNumber;
-
-class LTMatch extends AttributeMatch<Number> {
- Number value;
-
- protected LTMatch(Number value) {
- this.value = value;
- }
-
+/**
+ * GTMatch performs a "less than" number comparison via {@link NumberComparator}.
+ */
+class LTMatch implements Match {
  @Nullable
- public Boolean eval(Object attributeValue) {
- try {
- if(isValidNumber(attributeValue)) {
- return castToValueType(attributeValue, value).doubleValue() < value.doubleValue();
- }
- } catch (Exception e) {
- return null;
- }
- return null;
+ public Boolean eval(Object conditionValue, Object attributeValue) throws UnknownValueTypeException {
+ return NumberComparator.compare(attributeValue, conditionValue) < 0;
  }
 }
-

core-api/src/main/java/com/optimizely/ab/config/audience/match/LTMatch.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2018-2019, Optimizely and contributors
+ * Copyright 2018-2020, Optimizely and contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,5 +20,5 @@
 
 public interface Match {
  @Nullable
- Boolean eval(Object attributeValue);
+ Boolean eval(Object conditionValue, Object attributeValue) throws UnexpectedValueTypeException, UnknownValueTypeException;
 }