ATLAS-1904: Relationship def validation(s)

Signed-off-by: apoorvnaik <apoorvnaik@apache.org>
diff --git a/intg/src/main/java/org/apache/atlas/AtlasErrorCode.java b/intg/src/main/java/org/apache/atlas/AtlasErrorCode.java
index 49ead6e..73dd33a 100644
--- a/intg/src/main/java/org/apache/atlas/AtlasErrorCode.java
+++ b/intg/src/main/java/org/apache/atlas/AtlasErrorCode.java
@@ -77,7 +77,7 @@
     RELATIONSHIPDEF_ASSOCIATION_AND_CONTAINER(400,  "ATLAS-400-00-030", "ASSOCIATION relationshipDef {0} creation attempted with an end specifying isContainer"),
     RELATIONSHIPDEF_COMPOSITION_NO_CONTAINER(400,  "ATLAS-400-00-031", "COMPOSITION relationshipDef {0} creation attempted without an end specifying isContainer"),
     RELATIONSHIPDEF_AGGREGATION_NO_CONTAINER(400,  "ATLAS-400-00-032", "AGGREGATION relationshipDef {0} creation attempted without an end specifying isContainer"),
-    RELATIONSHIPDEF_COMPOSITION_SET_CONTAINER(400,  "ATLAS-400-00-033", "COMPOSITION relationshipDef {0} cannot have a SET cardinality and be a container"),
+    RELATIONSHIPDEF_COMPOSITION_MULTIPLE_PARENTS(400,  "ATLAS-400-00-033", "COMPOSITION relationshipDef {0} can only have one parent; so cannot have SET cardinality on children"),
     RELATIONSHIPDEF_LIST_ON_END(400,  "ATLAS-400-00-034", "relationshipDef {0} cannot have a LIST cardinality on an end"),
     RELATIONSHIPDEF_INVALID_END_TYPE(400,  "ATLAS-400-00-035", "relationshipDef {0} has invalid end type {1}"),
     INVALID_RELATIONSHIP_END_TYPE(400, "ATLAS-400-00-036", "invalid update for relationshipDef {0}: new end type {1}, existing end type {2}"),
diff --git a/intg/src/main/java/org/apache/atlas/type/AtlasRelationshipType.java b/intg/src/main/java/org/apache/atlas/type/AtlasRelationshipType.java
index f85cf35..49a9493 100644
--- a/intg/src/main/java/org/apache/atlas/type/AtlasRelationshipType.java
+++ b/intg/src/main/java/org/apache/atlas/type/AtlasRelationshipType.java
@@ -161,6 +161,10 @@
         boolean                 isContainer1         = endDef1.getIsContainer();
         boolean                 isContainer2         = endDef2.getIsContainer();
 
+        if ((endDef1.getCardinality() == AtlasAttributeDef.Cardinality.LIST) ||
+                (endDef2.getCardinality() == AtlasAttributeDef.Cardinality.LIST)) {
+            throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_LIST_ON_END, name);
+        }
         if (isContainer1 && isContainer2) {
             // we support 0 or 1 of these flags.
             throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_DOUBLE_CONTAINERS, name);
@@ -168,11 +172,11 @@
         if ((isContainer1 || isContainer2)) {
             // we have an isContainer defined in an end
             if (relationshipCategory == RelationshipCategory.ASSOCIATION) {
-                // associations are not containment relaitonships - so do not allow an endpoiint with isContainer
+                // associations are not containment relationships - so do not allow an endpoint with isContainer
                 throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_ASSOCIATION_AND_CONTAINER, name);
             }
         } else {
-            // we do not have an isContainer defined in an end
+            // we do not have an isContainer defined on an end
             if (relationshipCategory == RelationshipCategory.COMPOSITION) {
                 // COMPOSITION needs one end to be the container.
                 throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_NO_CONTAINER, name);
@@ -182,18 +186,14 @@
             }
         }
         if (relationshipCategory == RelationshipCategory.COMPOSITION) {
-            // composition containers should not be multiple cardinality
+            // composition children should not be multiple cardinality
             if (endDef1.getCardinality() == AtlasAttributeDef.Cardinality.SET &&
-                    endDef1.getIsContainer()) {
-                throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_SET_CONTAINER, name);
+                    !endDef1.getIsContainer()) {
+                throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_MULTIPLE_PARENTS, name);
             }
             if ((endDef2.getCardinality() == AtlasAttributeDef.Cardinality.SET) &&
-                    endDef2.getIsContainer()) {
-                throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_SET_CONTAINER, name);
-            }
-            if ((endDef1.getCardinality() == AtlasAttributeDef.Cardinality.LIST) ||
-                    (endDef2.getCardinality() == AtlasAttributeDef.Cardinality.LIST)) {
-                throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_LIST_ON_END, name);
+                    !endDef2.getIsContainer()) {
+                throw new AtlasBaseException(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_MULTIPLE_PARENTS, name);
             }
         }
     }
diff --git a/intg/src/test/java/org/apache/atlas/type/TestAtlasRelationshipType.java b/intg/src/test/java/org/apache/atlas/type/TestAtlasRelationshipType.java
index 41aac8f..8f3ac5b 100644
--- a/intg/src/test/java/org/apache/atlas/type/TestAtlasRelationshipType.java
+++ b/intg/src/test/java/org/apache/atlas/type/TestAtlasRelationshipType.java
@@ -61,22 +61,26 @@
 
     @Test
     public void testvalidateAtlasRelationshipDef() throws AtlasBaseException {
-        AtlasRelationshipEndDef ep1 = new AtlasRelationshipEndDef("typeA", "attr1", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE);
-        AtlasRelationshipEndDef ep2 = new AtlasRelationshipEndDef("typeB", "attr2", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE);
-        AtlasRelationshipEndDef ep3 = new AtlasRelationshipEndDef("typeC", "attr2", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE, true);
-        AtlasRelationshipEndDef ep4 = new AtlasRelationshipEndDef("typeD", "attr2", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE, true);
-        AtlasRelationshipEndDef ep5 = new AtlasRelationshipEndDef("typeA", "attr1", AtlasStructDef.AtlasAttributeDef.Cardinality.SET,true);
-        AtlasRelationshipEndDef ep6 = new AtlasRelationshipEndDef("typeA", "attr1", AtlasStructDef.AtlasAttributeDef.Cardinality.LIST,true);
+        AtlasRelationshipEndDef ep_single = new AtlasRelationshipEndDef("typeA", "attr1", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE);
+        AtlasRelationshipEndDef ep_single_container = new AtlasRelationshipEndDef("typeB", "attr2", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE);
+        AtlasRelationshipEndDef ep_single_container_2 = new AtlasRelationshipEndDef("typeC", "attr3", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE, true);
+        AtlasRelationshipEndDef ep_single_container_3 = new AtlasRelationshipEndDef("typeD", "attr4", AtlasStructDef.AtlasAttributeDef.Cardinality.SINGLE, true);
+        AtlasRelationshipEndDef ep_SET = new AtlasRelationshipEndDef("typeD", "attr4", AtlasStructDef.AtlasAttributeDef.Cardinality.SET,false);
+        AtlasRelationshipEndDef ep_LIST = new AtlasRelationshipEndDef("typeE", "attr5", AtlasStructDef.AtlasAttributeDef.Cardinality.LIST,true);
+        AtlasRelationshipEndDef ep_SET_container = new AtlasRelationshipEndDef("typeF", "attr6", AtlasStructDef.AtlasAttributeDef.Cardinality.SET,true);
         AtlasRelationshipDef relationshipDef1 = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                AtlasRelationshipDef.RelationshipCategory.ASSOCIATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep2);
+                AtlasRelationshipDef.RelationshipCategory.ASSOCIATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_single, ep_SET);
+        AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef1);
         AtlasRelationshipDef relationshipDef2 = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep3);
+                AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_SET_container, ep_single);
+        AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef2);
         AtlasRelationshipDef relationshipDef3 = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                AtlasRelationshipDef.RelationshipCategory.AGGREGATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep3);
+                AtlasRelationshipDef.RelationshipCategory.AGGREGATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_SET_container, ep_single);
+        AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef3);
 
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.ASSOCIATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep3, ep2);
+                    AtlasRelationshipDef.RelationshipCategory.ASSOCIATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_single_container_2, ep_single_container);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {
@@ -86,7 +90,7 @@
         }
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep2);
+                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_single, ep_single_container);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {
@@ -96,7 +100,7 @@
         }
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.AGGREGATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep2);
+                    AtlasRelationshipDef.RelationshipCategory.AGGREGATION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_single, ep_single_container);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {
@@ -107,17 +111,17 @@
 
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep5);
+                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_SET_container, ep_SET);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {
-            if (!abe.getAtlasErrorCode().equals(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_SET_CONTAINER)) {
+            if (!abe.getAtlasErrorCode().equals(AtlasErrorCode.RELATIONSHIPDEF_COMPOSITION_MULTIPLE_PARENTS)) {
                 fail("This call expected a different error");
             }
         }
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep1, ep6);
+                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_single, ep_LIST);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {
@@ -127,7 +131,7 @@
         }
         try {
             AtlasRelationshipDef relationshipDef = new AtlasRelationshipDef("emptyRelationshipDef", "desc 1", "version1",
-                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep6, ep1);
+                    AtlasRelationshipDef.RelationshipCategory.COMPOSITION, AtlasRelationshipDef.PropagateTags.ONE_TO_TWO, ep_LIST, ep_single);
             AtlasRelationshipType.validateAtlasRelationshipDef(relationshipDef);
             fail("This call is expected to fail");
         } catch (AtlasBaseException abe) {