handle empty containers in ProposedNew NestedTypes

Empty containers of NestedTypes were not handled in ProposedNew, causing
plans to be submitted with null values where there was configuration
present.

Author: jbardin

internal/plans/objchange/objchange.go

@@ -308,7 +308,9 @@ func proposedNewAttributes(attrs map[string]*configschema.Attribute, prior, conf
 }
 
 func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value) cty.Value {
-	var newV cty.Value
+	// If the config is null or empty, we will be using this default value.
+	newV := config
+
 	switch schema.Nesting {
 	case configschema.NestingSingle:
 		if !config.IsNull() {
@@ -323,6 +325,7 @@ func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value)
 		if config.IsKnown() && !config.IsNull() {
 			configVLen = config.LengthInt()
 		}
+
 		if configVLen > 0 {
 			newVals := make([]cty.Value, 0, configVLen)
 			for it := config.ElementIterator(); it.Next(); {
@@ -345,8 +348,6 @@ func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value)
 			} else {
 				newV = cty.ListVal(newVals)
 			}
-		} else {
-			newV = cty.NullVal(schema.ImpliedType())
 		}
 
 	case configschema.NestingMap:
@@ -378,8 +379,6 @@ func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value)
 				// object values so that elements might have different types
 				// in case of dynamically-typed attributes.
 				newV = cty.ObjectVal(newVals)
-			} else {
-				newV = cty.NullVal(schema.ImpliedType())
 			}
 		} else {
 			configVLen := 0
@@ -403,8 +402,6 @@ func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value)
 					newVals[k] = cty.ObjectVal(newEV)
 				}
 				newV = cty.MapVal(newVals)
-			} else {
-				newV = cty.NullVal(schema.ImpliedType())
 			}
 		}
 
@@ -446,8 +443,6 @@ func proposedNewNestedType(schema *configschema.Object, prior, config cty.Value)
 				}
 			}
 			newV = cty.SetVal(newVals)
-		} else {
-			newV = cty.NullVal(schema.ImpliedType())
 		}
 	}
 

internal/plans/objchange/objchange_test.go

@@ -1461,6 +1461,81 @@ func TestProposedNew(t *testing.T) {
 				}))),
 			}),
 		},
+		"expected empty NestedTypes": {
+			&configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"set": {
+						NestedType: &configschema.Object{
+							Nesting: configschema.NestingSet,
+							Attributes: map[string]*configschema.Attribute{
+								"bar": {Type: cty.String},
+							},
+						},
+						Optional: true,
+					},
+					"map": {
+						NestedType: &configschema.Object{
+							Nesting: configschema.NestingMap,
+							Attributes: map[string]*configschema.Attribute{
+								"bar": {Type: cty.String},
+							},
+						},
+						Optional: true,
+					},
+				},
+			},
+			cty.ObjectVal(map[string]cty.Value{
+				"map": cty.MapValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+				"set": cty.SetValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"map": cty.MapValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+				"set": cty.SetValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"map": cty.MapValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+				"set": cty.SetValEmpty(cty.Object(map[string]cty.Type{"bar": cty.String})),
+			}),
+		},
+		"optional types set replacement": {
+			&configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"set": {
+						NestedType: &configschema.Object{
+							Nesting: configschema.NestingSet,
+							Attributes: map[string]*configschema.Attribute{
+								"bar": {
+									Type:     cty.String,
+									Required: true,
+								},
+							},
+						},
+						Optional: true,
+					},
+				},
+			},
+			cty.ObjectVal(map[string]cty.Value{
+				"set": cty.SetVal([]cty.Value{
+					cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("old"),
+					}),
+				}),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"set": cty.SetVal([]cty.Value{
+					cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("new"),
+					}),
+				}),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"set": cty.SetVal([]cty.Value{
+					cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("new"),
+					}),
+				}),
+			}),
+		},
 	}
 
 	for name, test := range tests {