Add UUID provided function

core/src/main/java/com/schibsted/spt/data/jslt/impl/BuiltinFunctions.java

@@ -28,6 +28,7 @@
 import java.util.SimpleTimeZone;
 import java.util.TimeZone;
 import java.util.TreeSet;
+import java.util.UUID;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
@@ -103,6 +104,7 @@ public class BuiltinFunctions {
     functions.put("to-json", new BuiltinFunctions.ToJson());
     functions.put("replace", new BuiltinFunctions.Replace());
     functions.put("trim", new BuiltinFunctions.Trim());
+    functions.put("uuid", new BuiltinFunctions.Uuid());
 
     // BOOLEAN
     functions.put("not", new BuiltinFunctions.Not());
@@ -974,6 +976,48 @@ public JsonNode call(JsonNode input, JsonNode[] arguments) {
     }
   }
 
+  // ===== UUID
+
+  public static class Uuid extends AbstractFunction {
+
+    public Uuid() {
+      super("uuid", 0, 2);
+    }
+
+    private long maskMSB(long number) {
+      final long version = 1 << 12;
+      long least12SignificantBit = (number & 0x000000000000FFFFL) >> 4;
+      return (number & 0xFFFFFFFFFFFF0000L) + version + least12SignificantBit;
+    }
+
+    private long maskLSB(long number) {
+      final long LSB_MASK = 0x3FFFFFFFFFFFFFFFL;
+      final long LSB_VARIANT3_BITFLAG = 0x8000000000000000L;
+      return (number & LSB_MASK) + LSB_VARIANT3_BITFLAG;
+    }
+
+    public JsonNode call(JsonNode input, JsonNode[] arguments) {
+      String uuid;
+      if (arguments.length == 0) {
+        uuid = UUID.randomUUID().toString();
+      } else if (arguments.length == 2) {
+        // NIL UUID is a special case defined in 4.1.7 of the RFC (https://www.ietf.org/rfc/rfc4122.txt)
+        if (arguments[0].isNull() && arguments[1].isNull()) {
+          uuid = "00000000-0000-0000-0000-000000000000";
+        } else {
+          long msb = NodeUtils.number(arguments[0], null).asLong();
+          long lsb = NodeUtils.number(arguments[1], null).asLong();
+          uuid = new UUID(maskMSB(msb), maskLSB(lsb)).toString();
+        }
+      } else {
+        throw new JsltException("Build-in UUID function must be called with either none or two parameters.");
+      }
+
+      return new TextNode(uuid);
+    }
+  }
+
+
   // ===== JOIN
 
   public static class Join extends AbstractFunction {

core/src/test/java/com/schibsted/spt/data/jslt/buildinfunctions/UuidTest.java

@@ -0,0 +1,42 @@
+package com.schibsted.spt.data.jslt.buildinfunctions;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.schibsted.spt.data.jslt.Expression;
+import com.schibsted.spt.data.jslt.JsltException;
+import com.schibsted.spt.data.jslt.Parser;
+import com.schibsted.spt.data.jslt.TestBase;
+import org.junit.Test;
+
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+public class UuidTest extends TestBase {
+  private static ObjectMapper mapper = new ObjectMapper();
+
+  @Test
+  public void testUuidWithoutParameterMatchesRegex() throws JsonProcessingException {
+    Expression given = Parser.compileString("uuid()");
+    String actual = mapper.writeValueAsString(given.apply(null));
+
+    String uuidRegex = "^\"[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}\"$";
+    assertTrue(actual.matches(uuidRegex));
+  }
+
+  @Test
+  public void testUuidWithoutParameterGeneratesRandomValues() throws JsonProcessingException {
+    Expression given = Parser.compileString("{ \"uuid1\" : uuid(), \"uuid2\" : uuid() }");
+    JsonNode result = given.apply(null);
+    String actual1 = mapper.writeValueAsString(result.findValue("uuid1"));
+    String actual2 = mapper.writeValueAsString(result.findValue("uuid2"));
+
+    assertNotEquals(actual1, actual2);
+  }
+
+  @Test(expected = JsltException.class)
+  public void testUuidWithOneParameterRaisesJsltException() {
+    Expression given = Parser.compileString("uuid(123)");
+    given.apply(null);
+  }
+}

core/src/test/resources/function-tests.json

@@ -1142,6 +1142,41 @@
       "input" : "\"a\"",
       "output": "\"a\""
    },
+   {
+      "query": "uuid(9223372036854775807, 9223372036854775807)",
+      "input" : "null",
+      "output": "\"7fffffff-ffff-1fff-bfff-ffffffffffff\""
+   },
+   {
+      "query": "uuid(-9223372036854775808, -9223372036854775808)",
+      "input" : "null",
+      "output": "\"80000000-0000-1000-8000-000000000000\""
+   },
+   {
+      "query": "uuid(0, 0)",
+      "input" : "null",
+      "output": "\"00000000-0000-1000-8000-000000000000\""
+   },
+   {
+      "query": "uuid(null, 9223372036854775807)",
+      "input" : "null",
+      "output": "\"00000000-0000-1000-bfff-ffffffffffff\""
+   },
+   {
+      "query": "uuid(9223372036854775807, null)",
+      "input" : "null",
+      "output": "\"7fffffff-ffff-1fff-8000-000000000000\""
+   },
+   {
+      "query": "uuid(1234567890, 1234567890)",
+      "input" : "null",
+      "output": "\"00000000-4996-102d-8000-0000499602d2\""
+   },
+   {
+      "query": "uuid(null, null)",
+      "input" : "null",
+      "output": "\"00000000-0000-0000-0000-000000000000\""
+   },
    {
       "query": "min(1, 2)",
       "input" : "null",

functions.md

@@ -526,6 +526,22 @@ trim(false)        => "false"
 trim(null)         => null
 ```
 
+### _uuid(long, long) -> string_
+
+Generates a formatted UUID string with dashes.
+If no parameter are passed, a random UUID version 4 will be generated.
+If two parameter are passed, a UUID version 1 is generated based on two long values where the first parameter represents the MSB (most significant bytes) and the second parameter the LSB (least significant bytes) of the UUID.
+If both parameter are null a NIL UUID (00000000-0000-0000-0000-000000000000 is generated)
+
+Examples:
+
+```
+uuid()                       => "b02c39c0-6f8f-4250-97cd-78500af36e27"
+uuid(1234567890, 1234567890) => "00000000-4996-102d-8000-0000499602d2"
+uuid(0, 0)                   => "00000000-0000-1000-8000-000000000000"
+uuid(null, null)             => "00000000-0000-0000-0000-000000000000"
+```
+
 <!-- BOOLEAN ================================================================-->
 
 ## Boolean functions