MPEN-145: Added partial matching

proctor-common/src/main/java/com/indeed/proctor/common/ProctorRuleFunctions.java

@@ -80,4 +80,44 @@ public static boolean versionInRange(
         }
         return inRange(version, start, end);
     }
+
+    public static MaybeBool maybeAnd(final MaybeBool op1, final MaybeBool op2) {
+        if (MaybeBool.FALSE == op1 || MaybeBool.FALSE == op2) {
+            return MaybeBool.FALSE;
+        }
+        if (MaybeBool.TRUE == op1 && MaybeBool.TRUE == op2) {
+            return MaybeBool.TRUE;
+        }
+        return MaybeBool.UNKNOWN;
+    }
+
+    public static MaybeBool maybeOr(final MaybeBool op1, final MaybeBool op2) {
+        if (MaybeBool.TRUE == op1 || MaybeBool.TRUE == op2) {
+            return MaybeBool.TRUE;
+        }
+        if (MaybeBool.FALSE == op1 && MaybeBool.FALSE == op2) {
+            return MaybeBool.FALSE;
+        }
+        return MaybeBool.UNKNOWN;
+    }
+
+    public static MaybeBool maybeNot(final MaybeBool maybeBool) {
+        if (MaybeBool.TRUE == maybeBool) {
+            return MaybeBool.FALSE;
+        }
+        if (MaybeBool.FALSE == maybeBool) {
+            return MaybeBool.TRUE;
+        }
+        return MaybeBool.UNKNOWN;
+    }
+
+    public static MaybeBool toMaybeBool(final boolean b) {
+        return b ? MaybeBool.TRUE : MaybeBool.FALSE;
+    }
+
+    public enum MaybeBool {
+        TRUE,
+        FALSE,
+        UNKNOWN;
+    }
 }

proctor-common/src/main/java/com/indeed/proctor/common/RuleEvaluator.java

@@ -2,6 +2,7 @@
 
 import com.indeed.proctor.common.el.LibraryFunctionMapperBuilder;
 import com.indeed.proctor.common.el.MulticontextReadOnlyVariableMapper;
+import com.indeed.proctor.common.el.PartialExpressionBuilder;
 import org.apache.commons.lang3.ClassUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.el.ExpressionFactoryImpl;
@@ -21,7 +22,9 @@
 import javax.el.MapELResolver;
 import javax.el.ValueExpression;
 import javax.el.VariableMapper;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * A nice tidy packaging of javax.el stuff.
@@ -159,7 +162,64 @@ public boolean evaluateBooleanRuleWithValueExpr(
                         + " from rule "
                         + rule);
     }
+    /**
+     * @deprecated Use evaluateBooleanRulePartialWithValueExpr(String, Map) instead, it's more
+     *     efficient
+     */
+    @Deprecated
+    public boolean evaluateBooleanRulePartial(
+            final String rule, @Nonnull final Map<String, Object> values)
+            throws IllegalArgumentException {
+        final Map<String, ValueExpression> localContext =
+                ProctorUtils.convertToValueExpressionMap(expressionFactory, values);
+        return evaluateBooleanRulePartialWithValueExpr(rule, localContext);
+    }
+
+    /**
+     * This method should only be used for partial matching with proctor rules
+     * @return Evaluates a partial rule
+     **/
+    public boolean evaluateBooleanRulePartialWithValueExpr(
+            final String rule, @Nonnull final Map<String, ValueExpression> values)
+            throws IllegalArgumentException {
+        if (StringUtils.isBlank(rule)) {
+            return true;
+        }
+        if (!rule.startsWith("${") || !rule.endsWith("}")) {
+            LOGGER.error("Invalid rule '" + rule + "'"); //  TODO: should this be an exception?
+            return false;
+        }
+        final String bareRule = ProctorUtils.removeElExpressionBraces(rule);
+        if (StringUtils.isBlank(bareRule) || "true".equalsIgnoreCase(bareRule)) {
+            return true; //  always passes
+        }
+        if ("false".equalsIgnoreCase(bareRule)) {
+            return false;
+        }
+
+        final ELContext elContext = createElContext(values);
+        final Set<String> variablesDefined = new HashSet<>();
+        variablesDefined.addAll(values.keySet());
+        variablesDefined.addAll(testConstants.keySet());
+        final PartialExpressionBuilder builder =
+                new PartialExpressionBuilder(rule, elContext, variablesDefined);
+        final ValueExpression ve = builder.createValueExpression(boolean.class);
+        checkRuleIsBooleanType(rule, elContext, ve);
 
+        final Object result = ve.getValue(elContext);
+
+        if (result instanceof Boolean) {
+            return ((Boolean) result);
+        }
+        // this should never happen, evaluateRule throws ELException when it cannot coerce to
+        // Boolean
+        throw new IllegalArgumentException(
+                "Received non-boolean return value: "
+                        + (result == null ? "null" : result.getClass().getCanonicalName())
+                        + " from rule "
+                        + rule);
+    }
+
     /** @throws IllegalArgumentException if type of expression is not boolean */
     static void checkRuleIsBooleanType(
             final String rule, final ELContext elContext, final ValueExpression ve) {

proctor-common/src/main/java/com/indeed/proctor/common/el/NodeHunter.java

@@ -0,0 +1,175 @@
+package com.indeed.proctor.common.el;
+
+import com.google.common.collect.ImmutableList;
+import com.indeed.proctor.common.ProctorRuleFunctions.MaybeBool;
+import org.apache.el.parser.AstAnd;
+import org.apache.el.parser.AstFunction;
+import org.apache.el.parser.AstIdentifier;
+import org.apache.el.parser.AstLiteralExpression;
+import org.apache.el.parser.AstNot;
+import org.apache.el.parser.AstNotEqual;
+import org.apache.el.parser.AstOr;
+import org.apache.el.parser.ELParserTreeConstants;
+import org.apache.el.parser.Node;
+import org.apache.el.parser.NodeVisitor;
+import org.apache.el.parser.SimpleNode;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.Stack;
+import java.util.stream.Collectors;
+
+public class NodeHunter implements NodeVisitor {
+    private static final List<String> NODE_TYPES =
+            ImmutableList.copyOf(ELParserTreeConstants.jjtNodeName).stream()
+                    .map(nodeName -> "Ast" + nodeName)
+                    .collect(Collectors.toList());
+    private static final Map<String, Integer> NODE_TYPE_IDS =
+            NODE_TYPES.stream()
+                    .collect(Collectors.toMap(nodeType -> nodeType, NODE_TYPES::indexOf));
+    private static final int AST_FUNCTION_TYPE = 27;
+    private static final int AST_NOT_EQUAL_TYPE = 9;
+
+    private final Set<Node> initialUnknowns = Collections.newSetFromMap(new IdentityHashMap<>());
+    private final Map<Node, Node> replacements = new IdentityHashMap<>();
+    private final Set<String> variablesDefined;
+
+    NodeHunter(final Set<String> variablesDefined) {
+        this.variablesDefined = variablesDefined;
+    }
+
+    public static Node destroyUnknowns(final Node node, final Set<String> variablesDefined)
+            throws Exception {
+        final NodeHunter nodeHunter = new NodeHunter(variablesDefined);
+        node.accept(nodeHunter);
+        if (nodeHunter.initialUnknowns.isEmpty()) {
+            // Nothing to do here
+            return node;
+        }
+        nodeHunter.calculateReplacements();
+        final Node result = nodeHunter.replaceNodes(node);
+        // At this point result is a maybebool, we need to convert it to a bool
+        final Node resultIsNotFalse = nodeHunter.wrapIsNotFalse(result);
+        return resultIsNotFalse;
+    }
+
+    private void calculateReplacements() {
+        final Stack<Node> nodesToDestroy = new Stack<>();
+        initialUnknowns.forEach(nodesToDestroy::push);
+        while (!nodesToDestroy.isEmpty()) {
+            final Node nodeToDestroy = nodesToDestroy.pop();
+            if (nodeToDestroy instanceof AstAnd) {
+                // Replace simple "and" with maybeAnd
+                replaceWithFunction(nodeToDestroy, "maybeAnd");
+            } else if (nodeToDestroy instanceof AstOr) {
+                // Replace simple "or" with maybeOr
+                replaceWithFunction(nodeToDestroy, "maybeOr");
+            } else if (nodeToDestroy instanceof AstNot) {
+                // Replace simple "not" with maybeNot
+                replaceWithFunction(nodeToDestroy, "maybeNot");
+                // } else if (nodeToDestroy instanceof AstEqual || nodeToDestroy instanceof
+                // AstNotEqual) {
+                // TODO: if someone compares two bools using == that would be
+                // weird, but we could handle it by making sure any cases that mix
+                // maybeBool and bool are promoted to maybeBool like we do with the
+                // other logical operators
+            } else if (!replacements.containsKey(nodeToDestroy)) {
+                // Anything else propagate the unknown value
+                //
+                // TODO: If a bool is used as an argument to a function we
+                // could try and do the function if the maybeBool is true or
+                // false, and only propagate the unknown if any argument is
+                // unknown, but that seems rare and very complicated so I
+                // haven't handled that case here.
+                final AstLiteralExpression replacement = new AstLiteralExpression(1);
+                replacement.setImage(MaybeBool.UNKNOWN.name());
+                replacements.put(nodeToDestroy, replacement);
+            }
+            if (nodeToDestroy.jjtGetParent() != null) {
+                nodesToDestroy.push(nodeToDestroy.jjtGetParent());
+            }
+        }
+    }
+
+    private AstFunction createFunctionReplacement(final Node node, final String function) {
+        final AstFunction replacement = new AstFunction(AST_FUNCTION_TYPE);
+        replacement.setPrefix("proctor");
+        replacement.setLocalName(function);
+        replacement.setImage("proctor:" + function);
+        for (int i = 0; i < node.jjtGetNumChildren(); i++) {
+            final Node child = node.jjtGetChild(i);
+            if (replacements.containsKey(child)) {
+                replacement.jjtAddChild(replacements.get(child), i);
+            } else {
+                final AstFunction replacementChild = new AstFunction(AST_FUNCTION_TYPE);
+                replacementChild.setPrefix("proctor");
+                replacementChild.setLocalName("toMaybeBool");
+                replacementChild.setImage("proctor:toMaybeBool");
+                replacementChild.jjtAddChild(child, 0);
+                replacement.jjtAddChild(replacementChild, i);
+            }
+        }
+
+        return replacement;
+    }
+
+    private void replaceWithFunction(final Node node, final String function) {
+        final AstFunction replacement = createFunctionReplacement(node, function);
+        replacements.put(node, replacement);
+    }
+
+    private Node replaceNodes(final Node node)
+            throws NoSuchMethodException, InvocationTargetException, IllegalAccessException,
+                    InstantiationException {
+        if (replacements.containsKey(node)) {
+            Node newNode = node;
+            while (replacements.containsKey(newNode)) {
+                newNode = replacements.get(newNode);
+            }
+            return newNode;
+        }
+        final Class<?> nodeClass = node.getClass();
+        final Constructor<?> constructor = nodeClass.getConstructor(int.class);
+        final SimpleNode newNode =
+                (SimpleNode) constructor.newInstance(NODE_TYPE_IDS.get(nodeClass.getSimpleName()));
+        for (int i = 0; i < node.jjtGetNumChildren(); i++) {
+            final Node newChild = replaceNodes(node.jjtGetChild(i));
+            newChild.jjtSetParent(newNode);
+            newNode.jjtAddChild(newChild, i);
+        }
+        newNode.jjtSetParent(node.jjtGetParent());
+        newNode.setImage(node.getImage());
+        if (newNode instanceof AstFunction) {
+            ((AstFunction) newNode).setPrefix(((AstFunction) node).getPrefix());
+            ((AstFunction) newNode).setLocalName(((AstFunction) node).getLocalName());
+        }
+        return newNode;
+    }
+
+    @Override
+    public void visit(final Node node) throws Exception {
+        if (node instanceof AstIdentifier) {
+            String variable = node.getImage();
+            if (!variablesDefined.contains(variable)) {
+                initialUnknowns.add(node);
+            }
+        }
+    }
+
+    private Node wrapIsNotFalse(final Node node) {
+        final Node resultIsNotFalse = new AstNotEqual(AST_NOT_EQUAL_TYPE);
+        final AstLiteralExpression literalFalse = new AstLiteralExpression(1);
+        literalFalse.setImage(MaybeBool.FALSE.name());
+        literalFalse.jjtSetParent(resultIsNotFalse);
+        resultIsNotFalse.jjtSetParent(node.jjtGetParent());
+        node.jjtSetParent(resultIsNotFalse);
+        resultIsNotFalse.jjtAddChild(node, 0);
+        resultIsNotFalse.jjtAddChild(literalFalse, 1);
+        return resultIsNotFalse;
+    }
+}