reverted change to lotto.json, added test case for functions in predicates

json-path-assert/src/test/resources/lotto.json

@@ -1,6 +1,5 @@
 {
   "lotto": {
-    "maxAverage": 100,
     "lottoId": 5,
     "winning-numbers": [
       2,

json-path/src/main/java/com/jayway/jsonpath/AggregationMapReduce.java

@@ -1,23 +0,0 @@
-package com.jayway.jsonpath;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.List;
-
-/**
- * Defines a pattern for taking a collection of input streams and executing the same path operation across all files
- * map / reducing the results as they come in to provide an aggregation function on top of the
- *
- * Created by matt@mjgreenwood.net on 6/26/15.
- */
-public class AggregationMapReduce {
-
-    public static void main(String args[]) throws IOException {
-        ReadContext ctx = JsonPath.parse(new File("/home/mattg/dev/JsonPath/json-path-assert/src/test/resources/lotto.json"));
-        List<String> numbers = ctx.read("$.lotto.winners..numbers.%sum()");
-
-        Object value = ctx.read("$.lotto.winners.[?(@.winnerId > $.lotto.winners.%length())].numbers.%avg()");
-        System.out.println(numbers);
-        System.out.println(value);
-    }
-}

json-path/src/main/java/com/jayway/jsonpath/internal/function/numeric/Min.java

@@ -10,7 +10,7 @@ public class Min extends AbstractAggregation {
 
     @Override
     protected void next(Number value) {
-        if (min < value.doubleValue()) {
+        if (min > value.doubleValue()) {
             min = value.doubleValue();
         }
     }

json-path/src/main/java/com/jayway/jsonpath/internal/token/FunctionPathToken.java

@@ -34,17 +34,23 @@ public class FunctionPathToken extends PathToken {
     @Override
     public void evaluate(String currentPath, PathRef parent, Object model, EvaluationContextImpl ctx) {
         Function function = FunctionFactory.newFunction(functionName);
-        ctx.addResult(currentPath, parent, function.invoke(currentPath, parent, model, ctx));
+        Object result = function.invoke(currentPath, parent, model, ctx);
+        ctx.addResult(currentPath, parent, result);
     }
 
+    /**
+     * Return the actual value by indicating true. If this return was false then we'd return the value in an array which
+     * isn't what is desired - true indicates the raw value is returned.
+     *
+     * @return
+     */
     @Override
     boolean isTokenDefinite() {
-        return false;
+        return true;
     }
 
     @Override
     String getPathFragment() {
         return pathFragment;
     }
-
 }

json-path/src/main/java/com/jayway/jsonpath/internal/token/PathToken.java

@@ -73,9 +73,6 @@ public abstract class PathToken {
             PathRef pathRef = ctx.forUpdate() ? PathRef.create(model, property) : PathRef.NO_OP;
             if (isLeaf()) {
                 ctx.addResult(evalPath, pathRef, propertyVal);
-//            } else if (isFunction()) {
-//                Function function = FunctionFactory.newFunction(next.getPathFragment());
-//                next.invoke(function, evalPath, pathRef, propertyVal, ctx);
             }
             else {
                 next().evaluate(evalPath, pathRef, propertyVal, ctx);
@@ -153,10 +150,6 @@ public abstract class PathToken {
         return next == null;
     }
 
-//    boolean isFunction() {
-//        return null != next && next.getPathFragment().startsWith("['%");
-//    }
-
     boolean isRoot() {
         return  prev == null;
     }

json-path/src/test/java/com/jayway/jsonpath/functions/BaseFunctionTest.java

@@ -2,6 +2,9 @@ package com.jayway.jsonpath.functions;
 
 import com.jayway.jsonpath.Configuration;
 
+import java.io.IOException;
+import java.util.Scanner;
+
 import static com.jayway.jsonpath.JsonPath.using;
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -33,4 +36,8 @@ public class BaseFunctionTest {
     protected void verifyMathFunction(String pathExpr, Object expectedValue) {
         verifyFunction(pathExpr, NUMBER_SERIES, expectedValue);
     }
+
+    protected String getResourceAsText(String resourceName) throws IOException {
+        return new Scanner(BaseFunctionTest.class.getResourceAsStream(resourceName), "UTF-8").useDelimiter("\\A").next();
+    }
 }

json-path/src/test/java/com/jayway/jsonpath/functions/JSONEntityFunctionTest.java

@@ -1,7 +1,10 @@
 package com.jayway.jsonpath.functions;
 
+import net.minidev.json.JSONArray;
 import org.junit.Test;
 
+import java.io.IOException;
+
 /**
  * Verifies methods that are helper implementations of functions for manipulating JSON entities, i.e.
  * length, etc.
@@ -9,6 +12,42 @@ import org.junit.Test;
  * Created by mattg on 6/27/15.
  */
 public class JSONEntityFunctionTest extends BaseFunctionTest {
+
+    private static final String BATCH_JSON = "{\n" +
+            "  \"batches\": {\n" +
+            "    \"minBatchSize\": 10,\n" +
+            "    \"results\": [\n" +
+            "      {\n" +
+            "        \"productId\": 23,\n" +
+            "        \"values\": [\n" +
+            "          2,\n" +
+            "          45,\n" +
+            "          34,\n" +
+            "          23,\n" +
+            "          3,\n" +
+            "          5,\n" +
+            "          4,\n" +
+            "          3,\n" +
+            "          2,\n" +
+            "          1,\n" +
+            "        ]\n" +
+            "      },\n" +
+            "      {\n" +
+            "        \"productId\": 23,\n" +
+            "        \"values\": [\n" +
+            "          52,\n" +
+            "          3,\n" +
+            "          12,\n" +
+            "          11,\n" +
+            "          18,\n" +
+            "          22,\n" +
+            "          1\n" +
+            "        ]\n" +
+            "      }\n" +
+            "    ]\n" +
+            "  }\n" +
+            "}";
+
     @Test
     public void testLengthOfTextArray() {
         // The length of JSONArray is an integer
@@ -20,4 +59,38 @@ public class JSONEntityFunctionTest extends BaseFunctionTest {
         // The length of JSONArray is an integer
         verifyFunction("$.numbers.%length()", NUMBER_SERIES, 10);
     }
+
+    /**
+     * The fictitious use-case/story - is we have a collection of batches with values indicating some quality metric.
+     * We want to determine the average of the values for only the batch's values where the number of items in the batch
+     * is greater than the min batch size which is encoded in the JSON document.
+     *
+     * We use the length function in the predicate to determine the number of values in each batch and then for those
+     * batches where the count is greater than min we calculate the average batch value.
+     *
+     * Its completely contrived example, however, this test exercises functions within predicates.
+     */
+    @Test
+    public void testPredicateWithFunctionCallSingleMatch() {
+        String path = "$.batches.results[?(@.values.%length() >= $.batches.minBatchSize)].values.%avg()";
+
+        // Its an array because in some use-cases the min size might match more than one batch and thus we'll get
+        // the average out for each collection
+        JSONArray values = new JSONArray();
+        values.add(12.2d);
+        verifyFunction(path, BATCH_JSON, values);
+    }
+
+    @Test
+    public void testPredicateWithFunctionCallTwoMatches() {
+        String path = "$.batches.results[?(@.values.%length() >= 3)].values.%avg()";
+
+        // Its an array because in some use-cases the min size might match more than one batch and thus we'll get
+        // the average out for each collection
+        JSONArray values = new JSONArray();
+        values.add(12.2d);
+        values.add(17d);
+        verifyFunction(path, BATCH_JSON, values);
+    }
+
 }

json-path/src/test/java/com/jayway/jsonpath/functions/NumericFunctionTest.java

@@ -25,7 +25,7 @@ public class NumericFunctionTest extends BaseFunctionTest {
 
     @Test
     public void testAverageOfDoubles() {
-        verifyMathFunction("$.numbers.%average()", (10d * (10d + 1d)) / 2d);
+        verifyMathFunction("$.numbers.%avg()", 5.5);
     }
 
     @Test
@@ -45,7 +45,7 @@ public class NumericFunctionTest extends BaseFunctionTest {
 
     @Test
     public void testStdDevOfDouble() {
-        verifyMathFunction("$.numbers.%stddev()", 1d);
+        verifyMathFunction("$.numbers.%stddev()", 2.8722813232690143d);
     }
 
     /**