types: Remove Attrs, AttrTypes, Elems, ElemTypes, Null, Unknown, and Value fields

.changelog/523.txt

@@ -0,0 +1,47 @@
+```release-note:breaking-change
+types: The `Bool` type `Null`, `Unknown`, and `Value` fields have been removed. Use the `BoolNull()`, `BoolUnknown()`, and `BoolValue()` creation functions and `IsNull()`, `IsUnknown()`, and `ValueBool()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Float64` type `Null`, `Unknown`, and `Value` fields have been removed. Use the `Float64Null()`, `Float64Unknown()`, and `Float64Value()` creation functions and `IsNull()`, `IsUnknown()`, and `ValueFloat64()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Int64` type `Null`, `Unknown`, and `Value` fields have been removed. Use the `Int64Null()`, `Int64Unknown()`, and `Int64Value()` creation functions and `IsNull()`, `IsUnknown()`, and `ValueInt64()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `List` type `Elems`, `ElemType`, `Null`, and `Unknown` fields have been removed. Use the `ListNull()`, `ListUnknown()`, `ListValue()`, and `ListValueMust()` creation functions and `Elements()`, `ElementsAs()`, `ElementType()`, `IsNull()`, and `IsUnknown()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Map` type `Elems`, `ElemType`, `Null`, and `Unknown` fields have been removed. Use the `MapNull()`, `MapUnknown()`, `MapValue()`, and `MapValueMust()` creation functions and `Elements()`, `ElementsAs()`, `ElementType()`, `IsNull()`, and `IsUnknown()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Number` type `Null`, `Unknown`, and `Value` fields have been removed. Use the `NumberNull()`, `NumberUnknown()`, and `NumberValue()` creation functions and `IsNull()`, `IsUnknown()`, and `ValueBigFloat()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Object` type `Attrs`, `AttrTypes`, `Null`, and `Unknown` fields have been removed. Use the `ObjectNull()`, `ObjectUnknown()`, `ObjectValue()`, and `ObjectValueMust()` creation functions and `As()`, `Attributes()`, `AttributeTypes()`, `IsNull()`, and `IsUnknown()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `Set` type `Elems`, `ElemType`, `Null`, and `Unknown` fields have been removed. Use the `SetNull()`, `SetUnknown()`, `SetValue()`, and `SetValueMust()` creation functions and `Elements()`, `ElementsAs()`, `ElementType()`, `IsNull()`, and `IsUnknown()` methods instead.
+```
+
+```release-note:breaking-change
+types: The `String` type `Null`, `Unknown`, and `Value` fields have been removed. Use the `StringNull()`, `StringUnknown()`, and `StringValue()` creation functions and `IsNull()`, `IsUnknown()`, and `ValueString()` methods instead.
+```
+
+```release-note:enhancement
+attr: Added `ValueState` type, which custom types can use to consistently represent the three possible value states (known, null, and unknown)
+```
+
+```release-note:bug
+types: Prevented Terraform errors where the zero-value for any `attr.Value` types such as `String` would be a known value instead of null
+```
+
+```release-note:bug
+types: Prevented indeterminate behavior for any `attr.Value` types where they could be any combination of null, unknown, and/or known
+```

attr/value_state.go

@@ -0,0 +1,31 @@
+package attr
+
+import "fmt"
+
+const (
+	// ValueStateNull represents a value which is null.
+	//
+	// This value is 0 so it is the zero-value for types implementations.
+	ValueStateNull ValueState = 0
+
+	// ValueStateUnknown represents a value which is unknown.
+	ValueStateUnknown ValueState = 1
+
+	// ValueStateKnown represents a value which is known (not null or unknown).
+	ValueStateKnown ValueState = 2
+)
+
+type ValueState uint8
+
+func (s ValueState) String() string {
+	switch s {
+	case ValueStateKnown:
+		return "known"
+	case ValueStateNull:
+		return "null"
+	case ValueStateUnknown:
+		return "unknown"
+	default:
+		panic(fmt.Sprintf("unhandled ValueState in String: %d", s))
+	}
+}

internal/fromtftypes/attribute_path_step_test.go

@@ -43,7 +43,7 @@ func TestAttributePathStep(t *testing.T) {
 		"PathStepElementKeyValue": {
 			tfType:   tftypes.ElementKeyValue(tftypes.NewValue(tftypes.String, "test")),
 			attrType: types.StringType,
-			expected: path.PathStepElementKeyValue{Value: types.String{Value: "test"}},
+			expected: path.PathStepElementKeyValue{Value: types.StringValue("test")},
 		},
 		"PathStepElementKeyValue-error": {
 			tfType:        tftypes.ElementKeyValue(tftypes.NewValue(tftypes.String, "test")),

internal/fromtftypes/attribute_path_test.go

@@ -88,7 +88,7 @@ func TestAttributePath(t *testing.T) {
 					},
 				},
 			},
-			expected: path.Root("test").AtSetValue(types.String{Value: "test-value"}),
+			expected: path.Root("test").AtSetValue(types.StringValue("test-value")),
 		},
 		"AttributeName-ElementKeyValue-value-conversion-error": {
 			tfType: tftypes.NewAttributePath().WithAttributeName("test").WithElementKeyValue(tftypes.NewValue(tftypes.String, "test-value")),

internal/fromtftypes/value_test.go

@@ -27,7 +27,7 @@ func TestValue(t *testing.T) {
 		"empty-tftype": {
 			tfType:   tftypes.Value{},
 			attrType: types.BoolType,
-			expected: types.Bool{Null: true},
+			expected: types.BoolNull(),
 		},
 		"nil-attr-type": {
 			tfType:        tftypes.Value{},
@@ -44,47 +44,47 @@ func TestValue(t *testing.T) {
 		"bool-null": {
 			tfType:   tftypes.NewValue(tftypes.Bool, nil),
 			attrType: types.BoolType,
-			expected: types.Bool{Null: true},
+			expected: types.BoolNull(),
 		},
 		"bool-unknown": {
 			tfType:   tftypes.NewValue(tftypes.Bool, tftypes.UnknownValue),
 			attrType: types.BoolType,
-			expected: types.Bool{Unknown: true},
+			expected: types.BoolUnknown(),
 		},
 		"bool-value": {
 			tfType:   tftypes.NewValue(tftypes.Bool, true),
 			attrType: types.BoolType,
-			expected: types.Bool{Value: true},
+			expected: types.BoolValue(true),
 		},
 		"float64-null": {
 			tfType:   tftypes.NewValue(tftypes.Number, nil),
 			attrType: types.Float64Type,
-			expected: types.Float64{Null: true},
+			expected: types.Float64Null(),
 		},
 		"float64-unknown": {
 			tfType:   tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			attrType: types.Float64Type,
-			expected: types.Float64{Unknown: true},
+			expected: types.Float64Unknown(),
 		},
 		"float64-value": {
 			tfType:   tftypes.NewValue(tftypes.Number, big.NewFloat(1.2)),
 			attrType: types.Float64Type,
-			expected: types.Float64{Value: 1.2},
+			expected: types.Float64Value(1.2),
 		},
 		"int64-null": {
 			tfType:   tftypes.NewValue(tftypes.Number, nil),
 			attrType: types.Int64Type,
-			expected: types.Int64{Null: true},
+			expected: types.Int64Null(),
 		},
 		"int64-unknown": {
 			tfType:   tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			attrType: types.Int64Type,
-			expected: types.Int64{Unknown: true},
+			expected: types.Int64Unknown(),
 		},
 		"int64-value": {
 			tfType:   tftypes.NewValue(tftypes.Number, 123),
 			attrType: types.Int64Type,
-			expected: types.Int64{Value: 123},
+			expected: types.Int64Value(123),
 		},
 		"list-null": {
 			tfType: tftypes.NewValue(
@@ -96,10 +96,7 @@ func TestValue(t *testing.T) {
 			attrType: types.ListType{
 				ElemType: types.StringType,
 			},
-			expected: types.List{
-				ElemType: types.StringType,
-				Null:     true,
-			},
+			expected: types.ListNull(types.StringType),
 		},
 		"list-unknown": {
 			tfType: tftypes.NewValue(
@@ -111,10 +108,7 @@ func TestValue(t *testing.T) {
 			attrType: types.ListType{
 				ElemType: types.StringType,
 			},
-			expected: types.List{
-				ElemType: types.StringType,
-				Unknown:  true,
-			},
+			expected: types.ListUnknown(types.StringType),
 		},
 		"list-value": {
 			tfType: tftypes.NewValue(
@@ -128,27 +122,27 @@ func TestValue(t *testing.T) {
 			attrType: types.ListType{
 				ElemType: types.StringType,
 			},
-			expected: types.List{
-				ElemType: types.StringType,
-				Elems: []attr.Value{
-					types.String{Value: "test-value"},
+			expected: types.ListValueMust(
+				types.StringType,
+				[]attr.Value{
+					types.StringValue("test-value"),
 				},
-			},
+			),
 		},
 		"number-null": {
 			tfType:   tftypes.NewValue(tftypes.Number, nil),
 			attrType: types.NumberType,
-			expected: types.Number{Null: true},
+			expected: types.NumberNull(),
 		},
 		"number-unknown": {
 			tfType:   tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			attrType: types.NumberType,
-			expected: types.Number{Unknown: true},
+			expected: types.NumberUnknown(),
 		},
 		"number-value": {
 			tfType:   tftypes.NewValue(tftypes.Number, big.NewFloat(1.2)),
 			attrType: types.NumberType,
-			expected: types.Number{Value: big.NewFloat(1.2)},
+			expected: types.NumberValue(big.NewFloat(1.2)),
 		},
 		"object-null": {
 			tfType: tftypes.NewValue(
@@ -164,12 +158,11 @@ func TestValue(t *testing.T) {
 					"test_attr": types.StringType,
 				},
 			},
-			expected: types.Object{
-				AttrTypes: map[string]attr.Type{
+			expected: types.ObjectNull(
+				map[string]attr.Type{
 					"test_attr": types.StringType,
 				},
-				Null: true,
-			},
+			),
 		},
 		"object-unknown": {
 			tfType: tftypes.NewValue(
@@ -185,12 +178,11 @@ func TestValue(t *testing.T) {
 					"test_attr": types.StringType,
 				},
 			},
-			expected: types.Object{
-				AttrTypes: map[string]attr.Type{
+			expected: types.ObjectUnknown(
+				map[string]attr.Type{
 					"test_attr": types.StringType,
 				},
-				Unknown: true,
-			},
+			),
 		},
 		"object-value": {
 			tfType: tftypes.NewValue(
@@ -208,14 +200,14 @@ func TestValue(t *testing.T) {
 					"test_attr": types.StringType,
 				},
 			},
-			expected: types.Object{
-				AttrTypes: map[string]attr.Type{
+			expected: types.ObjectValueMust(
+				map[string]attr.Type{
 					"test_attr": types.StringType,
 				},
-				Attrs: map[string]attr.Value{
-					"test_attr": types.String{Value: "test-value"},
+				map[string]attr.Value{
+					"test_attr": types.StringValue("test-value"),
 				},
-			},
+			),
 		},
 		"set-null": {
 			tfType: tftypes.NewValue(
@@ -227,10 +219,7 @@ func TestValue(t *testing.T) {
 			attrType: types.SetType{
 				ElemType: types.StringType,
 			},
-			expected: types.Set{
-				ElemType: types.StringType,
-				Null:     true,
-			},
+			expected: types.SetNull(types.StringType),
 		},
 		"set-unknown": {
 			tfType: tftypes.NewValue(
@@ -242,10 +231,7 @@ func TestValue(t *testing.T) {
 			attrType: types.SetType{
 				ElemType: types.StringType,
 			},
-			expected: types.Set{
-				ElemType: types.StringType,
-				Unknown:  true,
-			},
+			expected: types.SetUnknown(types.StringType),
 		},
 		"set-value": {
 			tfType: tftypes.NewValue(
@@ -259,27 +245,27 @@ func TestValue(t *testing.T) {
 			attrType: types.SetType{
 				ElemType: types.StringType,
 			},
-			expected: types.Set{
-				ElemType: types.StringType,
-				Elems: []attr.Value{
-					types.String{Value: "test-value"},
+			expected: types.SetValueMust(
+				types.StringType,
+				[]attr.Value{
+					types.StringValue("test-value"),
 				},
-			},
+			),
 		},
 		"string-null": {
 			tfType:   tftypes.NewValue(tftypes.String, nil),
 			attrType: types.StringType,
-			expected: types.String{Null: true},
+			expected: types.StringNull(),
 		},
 		"string-unknown": {
 			tfType:   tftypes.NewValue(tftypes.String, tftypes.UnknownValue),
 			attrType: types.StringType,
-			expected: types.String{Unknown: true},
+			expected: types.StringUnknown(),
 		},
 		"string-value": {
 			tfType:   tftypes.NewValue(tftypes.String, "test-value"),
 			attrType: types.StringType,
-			expected: types.String{Value: "test-value"},
+			expected: types.StringValue("test-value"),
 		},
 	}