Change tail feature test to use valueMap instead of inject as to not be affected by GLV map ordering (#3193)

https://issues.apache.org/jira/browse/TINKERPOP-2491

Change tail feature test to use valueMap() instead of inject(map) as to not be affected by go's lack of ordered map data structure. Added a note to go limitations about the lack of native support for ordered map.

Author: andreachild

docs/src/reference/gremlin-variants.asciidoc

@@ -517,6 +517,9 @@ type implementation. To input a set into Gremlin-Go, a custom struct which imple
 will be serialized as a set. `gremlingo.NewSimpleSet` is a basic implementation of a set that is provided by Gremlin-Go
 that can be used to fulfill the `gremlingo.Set` interface if desired.
 
+* Go does not support ordered maps natively as the built-in `map` type does not guarantee iteration order. Traversal 
+results which contain maps may not preserve original ordering when deserialized into Go's native map types.
+
 [[gremlin-go-examples]]
 === Application Examples
 

gremlin-dotnet/test/Gremlin.Net.IntegrationTest/Gherkin/Gremlin.cs

@@ -448,7 +448,7 @@ private static IDictionary<string, List<Func<GraphTraversalSource, IDictionary<s
                {"g_V_asXaX_out_asXaX_out_asXaX_selectXmixed_aX_byXunfold_valuesXnameX_foldX_tailXlocal_2X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.V().As("a").Out().As("a").Out().As("a").Select<object>(Pop.Mixed, "a").By(__.Unfold<object>().Values<object>("name").Fold()).Tail<object>(Scope.Local, 2)}}, 
                {"g_VX1X_valuesXageX_tailXlocal_5X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.V(p["vid1"]).Values<object>("age").Tail<object>(Scope.Local, 50)}}, 
                {"g_injectXlistX1_2_3XX_tailXlocal_1X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.Inject<object>(new List<object> { 1, 2, 3 }).Tail<object>(Scope.Local, 1)}}, 
-               {"g_injectXa1_b2_c3X_tailXlocal_1X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.Inject<object>(new Dictionary<object, object> {{ "a", 1 }, { "b", 2 }, { "c", 3 }}).Tail<object>(Scope.Local, 1)}}, 
+               {"g_VX1X_valueMapXnameX_tailXlocal_1X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.V(p["vid1"]).ValueMap<object, object>("name").Tail<object>(Scope.Local, 1)}}, 
                {"g_injectX1_2_3X_tailXlocal_1X_unfold", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.Inject<object>(new List<object> { 1, 2, 3 }).Tail<object>(Scope.Local, 1).Unfold<object>()}}, 
                {"g_injectX1_2_3_4_5_6X_tailXlocal_1X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.Inject<object>(new List<object> { 1, 2, 3 }, new List<object> { 4, 5, 6 }).Tail<object>(Scope.Local, 1)}}, 
                {"g_injectX1_2_3_4_5X_tailXlocal_2X", new List<Func<GraphTraversalSource, IDictionary<string, object>, ITraversal>> {(g,p) =>g.Inject<object>(new List<object> { 1, 2, 3, 4, 5 }).Tail<object>(Scope.Local, 2)}}, 

gremlin-go/driver/cucumber/gremlin.go

@@ -418,7 +418,7 @@ var translationMap = map[string][]func(g *gremlingo.GraphTraversalSource, p map[
     "g_V_asXaX_out_asXaX_out_asXaX_selectXmixed_aX_byXunfold_valuesXnameX_foldX_tailXlocal_2X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.V().As("a").Out().As("a").Out().As("a").Select(gremlingo.Pop.Mixed, "a").By(gremlingo.T__.Unfold().Values("name").Fold()).Tail(gremlingo.Scope.Local, 2)}}, 
     "g_VX1X_valuesXageX_tailXlocal_5X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.V(p["vid1"]).Values("age").Tail(gremlingo.Scope.Local, 50)}}, 
     "g_injectXlistX1_2_3XX_tailXlocal_1X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.Inject([]interface{}{1, 2, 3}).Tail(gremlingo.Scope.Local, 1)}}, 
-    "g_injectXa1_b2_c3X_tailXlocal_1X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.Inject(map[interface{}]interface{}{"a": 1, "b": 2, "c": 3 }).Tail(gremlingo.Scope.Local, 1)}}, 
+    "g_VX1X_valueMapXnameX_tailXlocal_1X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.V(p["vid1"]).ValueMap("name").Tail(gremlingo.Scope.Local, 1)}}, 
     "g_injectX1_2_3X_tailXlocal_1X_unfold": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.Inject([]interface{}{1, 2, 3}).Tail(gremlingo.Scope.Local, 1).Unfold()}}, 
     "g_injectX1_2_3_4_5_6X_tailXlocal_1X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.Inject([]interface{}{1, 2, 3}, []interface{}{4, 5, 6}).Tail(gremlingo.Scope.Local, 1)}}, 
     "g_injectX1_2_3_4_5X_tailXlocal_2X": {func(g *gremlingo.GraphTraversalSource, p map[string]interface{}) *gremlingo.GraphTraversal {return g.Inject([]interface{}{1, 2, 3, 4, 5}).Tail(gremlingo.Scope.Local, 2)}}, 

gremlin-javascript/src/main/javascript/gremlin-javascript/test/cucumber/gremlin.js

@@ -421,7 +421,7 @@
     'g_V_asXaX_out_asXaX_out_asXaX_selectXmixed_aX_byXunfold_valuesXnameX_foldX_tailXlocal_2X': [(lambda g:g.V().as_('a').out().as_('a').out().as_('a').select(Pop.mixed, 'a').by(__.unfold().values('name').fold()).tail(Scope.local, 2))], 
     'g_VX1X_valuesXageX_tailXlocal_5X': [(lambda g, vid1=None:g.V(vid1).values('age').tail(Scope.local, 50))], 
     'g_injectXlistX1_2_3XX_tailXlocal_1X': [(lambda g:g.inject([1, 2, 3]).tail(Scope.local, 1))], 
-    'g_injectXa1_b2_c3X_tailXlocal_1X': [(lambda g:g.inject({ 'a': 1, 'b': 2, 'c': 3 }).tail(Scope.local, 1))], 
+    'g_VX1X_valueMapXnameX_tailXlocal_1X': [(lambda g, vid1=None:g.V(vid1).value_map('name').tail(Scope.local, 1))], 
     'g_injectX1_2_3X_tailXlocal_1X_unfold': [(lambda g:g.inject([1, 2, 3]).tail(Scope.local, 1).unfold())], 
     'g_injectX1_2_3_4_5_6X_tailXlocal_1X': [(lambda g:g.inject([1, 2, 3], [4, 5, 6]).tail(Scope.local, 1))], 
     'g_injectX1_2_3_4_5X_tailXlocal_2X': [(lambda g:g.inject([1, 2, 3, 4, 5]).tail(Scope.local, 2))], 

gremlin-python/src/main/python/radish/gremlin.py

@@ -239,16 +239,17 @@ Feature: Step - tail()
       | l[d[3].i] |
 
   # Test that Map local tail 1 - should still return single entry
-  Scenario: g_injectXa1_b2_c3X_tailXlocal_1X
-    Given the empty graph
+  Scenario: g_VX1X_valueMapXnameX_tailXlocal_1X
+    Given the modern graph
+    And using the parameter vid1 defined as "v[marko].id"
     And the traversal of
       """
-      g.inject(["a": 1, "b": 2, "c": 3]).tail(Scope.local, 1)
+      g.V(vid1).valueMap("name").tail(Scope.local, 1)
       """
     When iterated to list
     Then the result should be unordered
       | result |
-      | m[{"c": 3}] |
+      | m[{"name":["marko"]}] |
 
   # Test unfold() can be used to extract single elements from collections for tail
   Scenario: g_injectX1_2_3X_tailXlocal_1X_unfold