fix CoerceValue to handle changing dynamic types

Objects with DynamicPseudoType attributes can't be coerced within a map
if a concrete type is set. Change the Value type used to an Object when
there is a type mismatch.

configs/configschema/coerce_value.go

@@ -225,7 +225,29 @@ func (b *Block) coerceValue(in cty.Value, path cty.Path) (cty.Value, error) {
 						elems[key.AsString()] = val
 					}
 				}
+
+				// If the attribute values here contain any DynamicPseudoTypes,
+				// the concrete type must be an object.
+				useObject := false
+				switch {
+				case coll.Type().IsObjectType():
+					useObject = true
+				default:
+					// It's possible that we were given a map, and need to coerce it to an object
+					ety := coll.Type().ElementType()
+					for _, v := range elems {
+						if !v.Type().Equals(ety) {
+							useObject = true
+							break
+						}
+					}
+				}
+
+				if useObject {
+					attrs[typeName] = cty.ObjectVal(elems)
+				} else {
 					attrs[typeName] = cty.MapVal(elems)
+				}
 			default:
 				attrs[typeName] = cty.MapValEmpty(blockS.ImpliedType())
 			}

configs/configschema/coerce_value_test.go

@@ -436,6 +436,101 @@ func TestCoerceValue(t *testing.T) {
 			}),
 			``,
 		},
+		"dynamic value attributes": {
+			&Block{
+				BlockTypes: map[string]*NestedBlock{
+					"foo": {
+						Nesting: NestingMap,
+						Block: Block{
+							Attributes: map[string]*Attribute{
+								"bar": {
+									Type:     cty.String,
+									Optional: true,
+									Computed: true,
+								},
+								"baz": {
+									Type:     cty.DynamicPseudoType,
+									Optional: true,
+									Computed: true,
+								},
+							},
+						},
+					},
+				},
+			},
+			cty.ObjectVal(map[string]cty.Value{
+				"foo": cty.ObjectVal(map[string]cty.Value{
+					"a": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("beep"),
+					}),
+					"b": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("boop"),
+						"baz": cty.NumberIntVal(8),
+					}),
+				}),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"foo": cty.ObjectVal(map[string]cty.Value{
+					"a": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("beep"),
+						"baz": cty.NullVal(cty.DynamicPseudoType),
+					}),
+					"b": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("boop"),
+						"baz": cty.NumberIntVal(8),
+					}),
+				}),
+			}),
+			``,
+		},
+		"dynamic attributes in map": {
+			// Convert a block represented as a map to an object if a
+			// DynamicPseudoType causes the element types to mismatch.
+			&Block{
+				BlockTypes: map[string]*NestedBlock{
+					"foo": {
+						Nesting: NestingMap,
+						Block: Block{
+							Attributes: map[string]*Attribute{
+								"bar": {
+									Type:     cty.String,
+									Optional: true,
+									Computed: true,
+								},
+								"baz": {
+									Type:     cty.DynamicPseudoType,
+									Optional: true,
+									Computed: true,
+								},
+							},
+						},
+					},
+				},
+			},
+			cty.ObjectVal(map[string]cty.Value{
+				"foo": cty.MapVal(map[string]cty.Value{
+					"a": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("beep"),
+					}),
+					"b": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("boop"),
+					}),
+				}),
+			}),
+			cty.ObjectVal(map[string]cty.Value{
+				"foo": cty.ObjectVal(map[string]cty.Value{
+					"a": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("beep"),
+						"baz": cty.NullVal(cty.DynamicPseudoType),
+					}),
+					"b": cty.ObjectVal(map[string]cty.Value{
+						"bar": cty.StringVal("boop"),
+						"baz": cty.NullVal(cty.DynamicPseudoType),
+					}),
+				}),
+			}),
+			``,
+		},
 	}
 
 	for name, test := range tests {