Validate deserialization of flag data

4 files changed, 92 insertions, 8 deletions

diff --git a/vespajlib/abi-spec.json b/vespajlib/abi-spec.json
index 04f859e2802..7c9f1f31bff 100644
--- a/vespajlib/abi-spec.json
+++ b/vespajlib/abi-spec.json
@@ -2859,7 +2859,8 @@
     ],
     "methods": [
       "public static java.lang.String encode(java.util.Map)",
-      "public static java.lang.String escape(java.lang.String)"
+      "public static java.lang.String escape(java.lang.String)",
+      "public static boolean equals(java.lang.String, java.lang.String)"
     ],
     "fields": []
   },
diff --git a/vespajlib/pom.xml b/vespajlib/pom.xml
index 7631a2af0fb..1b23d024d29 100644
--- a/vespajlib/pom.xml
+++ b/vespajlib/pom.xml
@@ -39,6 +39,11 @@
       <scope>provided</scope>
     </dependency>
     <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
       <groupId>com.yahoo.vespa</groupId>
       <artifactId>annotations</artifactId>
       <version>${project.version}</version>
@@ -73,11 +78,6 @@
       <version>${project.version}</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>com.fasterxml.jackson.core</groupId>
-      <artifactId>jackson-databind</artifactId>
-      <scope>test</scope>
-    </dependency>
 
   </dependencies>
   <build>
diff --git a/vespajlib/src/main/java/com/yahoo/text/JSON.java b/vespajlib/src/main/java/com/yahoo/text/JSON.java
index cfff16c9aba..4091930ed0e 100644
--- a/vespajlib/src/main/java/com/yahoo/text/JSON.java
+++ b/vespajlib/src/main/java/com/yahoo/text/JSON.java
@@ -1,15 +1,23 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.text;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import java.util.Map;
+import java.util.Objects;
+
+import static com.yahoo.yolean.Exceptions.uncheck;
 
 /**
- * Static methods for working with the map textual format which is parsed by {@link MapParser}
+ * Static mthods for working with JSON.
  *
  * @author bratseth
  */
 public final class JSON {
 
+    private static final ObjectMapper mapper = new ObjectMapper();
+
     /** No instances */
     private JSON() {}
 
@@ -56,4 +64,17 @@ public final class JSON {
         return b != null ? b.toString() : s;
     }
 
+    /**
+     * Test whether two JSON strings are equal, e.g. the order of fields in an object is irrelevant.
+     *
+     * <p>When comparing two numbers of the two JSON strings, the result is only guaranteed to be
+     * correct if (a) both are integers (without fraction and exponent) and each fits in a long, or
+     * (b) both are non-integers, were syntactically identical, and fits in a double.</p>
+     */
+    public static boolean equals(String left, String right) {
+        JsonNode leftJsonNode = uncheck(() -> mapper.readTree(left));
+        JsonNode rightJsonNode = uncheck(() -> mapper.readTree(right));
+        return Objects.equals(leftJsonNode, rightJsonNode);
+    }
+
 }
diff --git a/vespajlib/src/test/java/com/yahoo/text/JSONTest.java b/vespajlib/src/test/java/com/yahoo/text/JSONTest.java
index 22174761571..bba36a7cadd 100644
--- a/vespajlib/src/test/java/com/yahoo/text/JSONTest.java
+++ b/vespajlib/src/test/java/com/yahoo/text/JSONTest.java
@@ -2,11 +2,15 @@
 package com.yahoo.text;
 
 import org.junit.Test;
-import static org.junit.Assert.assertEquals;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
 /**
  * @author bratseth
  */
@@ -22,4 +26,62 @@ public class JSONTest {
         assertEquals("{\"a \\\"key\\\"\":3,\"key2\":\"value\",\"key3\":3.3}", JSON.encode(map));
     }
 
+    @Test
+    public void testEquals() {
+        assertTrue(JSON.equals("{}", "{}"));
+
+        // Whitespace is irrelevant
+        assertTrue(JSON.equals("{}", "\n{ }"));
+
+        // Order of fields in object is irrelevant
+        assertTrue(JSON.equals("{\"a\":0, \"c\":1}", "{\"c\":1, \"a\":0}"));
+
+        // Order of elements of array is significant
+        assertFalse(JSON.equals("[\"a\",\"b\"]", "[\"b\",\"c\"]"));
+
+        // Verify null-valued fields are not ignored
+        assertFalse(JSON.equals("{\"a\":null}", "{}"));
+
+        // Current impl uses BigInteger if integer doesn't fit in a long.
+        assertEquals(9223372036854775807L, Long.MAX_VALUE);
+        assertTrue(JSON.equals("{\"a\": 9223372036854775807}", "{\"a\": 9223372036854775807}"));
+
+        // double 1.0 and int 1 are different
+        assertTrue(JSON.equals( "{\"a\": 1}",  "{\"a\": 1}"));
+        assertTrue(JSON.equals( "{\"a\": 1.0}",  "{\"a\": 1.0}"));
+        assertFalse(JSON.equals( "{\"a\": 1.0}",  "{\"a\": 1}"));
+
+        // Double-precision on numbers. Constant from Math.E.
+        assertTrue(JSON.equals( "{\"e\": 2.71828182845904}",  "{\"e\": 2.71828182845904}"));
+
+        // Justification of above float values
+        double e1 = 2.7182818284590452354;
+        double e2 = 2.718281828459045;
+        double e3 = 2.71828182845904;
+        assertEquals(e1, Math.E, -1);
+        assertEquals(e1, e2, -1);
+        assertNotEquals(e1, e3, -1);
+
+        // Impl uses BigInteger
+        assertTrue(JSON.equals( "{\"a\": 92233720368547758070}",
+                                "{\"a\": 92233720368547758070}"));
+        assertFalse(JSON.equals("{\"a\": 92233720368547758070}",
+                                "{\"a\": 92233720368547758071}"));
+
+        // Impl converts to double and ignores extraneous digits
+        assertTrue(JSON.equals( "{\"e\": 2.7182818284590452354}",
+                                "{\"e\": 2.7182818284590452354}"));
+        assertTrue(JSON.equals( "{\"e\": 2.7182818284590452354}",
+                                "{\"e\": 2.7182818284590452355}"));
+        assertFalse(JSON.equals("{\"e\": 2.7182818284590452354}",
+                                "{\"e\": 2.71828182845904}"));
+
+        // Misc impl defined results
+        assertFalse(JSON.equals("{\"a\": 1.0}", "{\"a\":1}"));
+        assertTrue(JSON.equals("{\"a\": 1.0}", "{\"a\":1.00}"));
+        assertTrue(JSON.equals("{\"a\": 1.0}", "{\"a\":1.0000000000000000000000000000}"));
+        assertTrue(JSON.equals("{\"a\": 10.0}", "{\"a\":1e1}"));
+        assertTrue(JSON.equals("{\"a\": 1.2}", "{\"a\":12e-1}"));
+    }
+
 }