Add support for unknown/computed values in the structured renderer (#32378)

* prep for processing the structured run output

* undo unwanted change to a json key

* Add skeleton functions and API for refactored renderer

* goimports

* Fix documentation of the RenderOpts struct

* Add rendering functionality for primitives to the structured renderer

* add test case for override

* Add support for parsing and rendering sensitive values in the renderer

* Add support for unknown/computed values in the structured renderer

* delete missing unit tests

internal/command/jsonformat/change/computed.go

@@ -0,0 +1,29 @@
+package change
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/terraform/internal/plans"
+)
+
+func Computed(before Change) Renderer {
+	return &computedRenderer{
+		before: before,
+	}
+}
+
+type computedRenderer struct {
+	NoWarningsRenderer
+
+	before Change
+}
+
+func (renderer computedRenderer) Render(change Change, indent int, opts RenderOpts) string {
+	if change.action == plans.Create {
+		return "(known after apply)"
+	}
+
+	// Never render null suffix for children of computed changes.
+	opts.overrideNullSuffix = true
+	return fmt.Sprintf("%s -> (known after apply)", renderer.before.Render(indent, opts))
+}

internal/command/jsonformat/change/primitive.go

@@ -7,7 +7,7 @@ import (
 )
 
 func Primitive(before, after *string) Renderer {
-	return primitiveRenderer{
+	return &primitiveRenderer{
 		before: before,
 		after:  after,
 	}

internal/command/jsonformat/change/renderer_test.go

@@ -28,7 +28,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(nil, strptr("1")),
 				action:   plans.Create,
-				replace:  false,
 			},
 			expected: "1",
 		},
@@ -36,7 +35,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(strptr("1"), nil),
 				action:   plans.Delete,
-				replace:  false,
 			},
 			expected: "1 -> null",
 		},
@@ -44,7 +42,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(strptr("1"), nil),
 				action:   plans.Delete,
-				replace:  false,
 			},
 			opts:     RenderOpts{overrideNullSuffix: true},
 			expected: "1",
@@ -53,7 +50,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(strptr("1"), nil),
 				action:   plans.Update,
-				replace:  false,
 			},
 			expected: "1 -> null",
 		},
@@ -61,7 +57,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(nil, strptr("1")),
 				action:   plans.Update,
-				replace:  false,
 			},
 			expected: "null -> 1",
 		},
@@ -69,7 +64,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Primitive(strptr("0"), strptr("1")),
 				action:   plans.Update,
-				replace:  false,
 			},
 			expected: "0 -> 1",
 		},
@@ -85,7 +79,6 @@ func TestRenderers(t *testing.T) {
 			change: Change{
 				renderer: Sensitive("0", "1", true, true),
 				action:   plans.Update,
-				replace:  false,
 			},
 			expected: "(sensitive)",
 		},
@@ -97,6 +90,23 @@ func TestRenderers(t *testing.T) {
 			},
 			expected: "(sensitive) # forces replacement",
 		},
+		"computed_create": {
+			change: Change{
+				renderer: Computed(Change{}),
+				action:   plans.Create,
+			},
+			expected: "(known after apply)",
+		},
+		"computed_update": {
+			change: Change{
+				renderer: Computed(Change{
+					renderer: Primitive(strptr("0"), nil),
+					action:   plans.Delete,
+				}),
+				action: plans.Update,
+			},
+			expected: "0 -> (known after apply)",
+		},
 	}
 	for name, tc := range tcs {
 		t.Run(name, func(t *testing.T) {

internal/command/jsonformat/change/sensitive.go

@@ -6,7 +6,7 @@ import (
 )
 
 func Sensitive(before, after interface{}, beforeSensitive, afterSensitive bool) Renderer {
-	return sensitiveRenderer{
+	return &sensitiveRenderer{
 		before:          before,
 		after:           after,
 		beforeSensitive: beforeSensitive,

internal/command/jsonformat/change/testing.go

@@ -20,7 +20,7 @@ func ValidateChange(t *testing.T, f ValidateChangeFunc, change Change, expectedA
 
 func ValidatePrimitive(before, after *string) ValidateChangeFunc {
 	return func(t *testing.T, change Change) {
-		primitive, ok := change.renderer.(primitiveRenderer)
+		primitive, ok := change.renderer.(*primitiveRenderer)
 		if !ok {
 			t.Fatalf("invalid renderer type: %T", change.renderer)
 		}
@@ -36,7 +36,7 @@ func ValidatePrimitive(before, after *string) ValidateChangeFunc {
 
 func ValidateSensitive(before, after interface{}, beforeSensitive, afterSensitive bool) ValidateChangeFunc {
 	return func(t *testing.T, change Change) {
-		sensitive, ok := change.renderer.(sensitiveRenderer)
+		sensitive, ok := change.renderer.(*sensitiveRenderer)
 		if !ok {
 			t.Fatalf("invalid renderer type: %T", change.renderer)
 		}
@@ -53,3 +53,25 @@ func ValidateSensitive(before, after interface{}, beforeSensitive, afterSensitiv
 		}
 	}
 }
+
+func ValidateComputed(before ValidateChangeFunc) ValidateChangeFunc {
+	return func(t *testing.T, change Change) {
+		computed, ok := change.renderer.(*computedRenderer)
+		if !ok {
+			t.Fatalf("invalid renderer type: %T", change.renderer)
+		}
+
+		if before == nil {
+			if computed.before.renderer != nil {
+				t.Fatalf("did not expect a before renderer, but found one")
+			}
+			return
+		}
+
+		if computed.before.renderer == nil {
+			t.Fatalf("expected a before renderer, but found none")
+		}
+
+		before(t, computed.before)
+	}
+}

internal/command/jsonformat/differ/attribute.go

@@ -14,10 +14,14 @@ func (v Value) ComputeChangeForAttribute(attribute *jsonprovider.Attribute) chan
 
 func (v Value) ComputeChangeForType(ctyType cty.Type) change.Change {
 
-	if sensitive, ok := v.CheckForSensitive(); ok {
+	if sensitive, ok := v.checkForSensitive(); ok {
 		return sensitive
 	}
 
+	if computed, ok := v.checkForComputed(ctyType); ok {
+		return computed
+	}
+
 	switch {
 	case ctyType.IsPrimitiveType():
 		return v.computeAttributeChangeAsPrimitive(ctyType)

internal/command/jsonformat/differ/computed.go

@@ -0,0 +1,41 @@
+package differ
+
+import (
+	"github.com/zclconf/go-cty/cty"
+
+	"github.com/hashicorp/terraform/internal/command/jsonformat/change"
+)
+
+func (v Value) checkForComputed(ctyType cty.Type) (change.Change, bool) {
+	unknown := v.isUnknown()
+
+	if !unknown {
+		return change.Change{}, false
+	}
+
+	// No matter what we do here, we want to treat the after value as explicit.
+	// This is because it is going to be null in the value, and we don't want
+	// the functions in this package to assume this means it has been deleted.
+	v.AfterExplicit = true
+
+	if v.Before == nil {
+		return v.AsChange(change.Computed(change.Change{})), true
+	}
+
+	// If we get here, then we have a before value. We're going to model a
+	// delete operation and our renderer later can render the overall change
+	// accurately.
+
+	beforeValue := Value{
+		Before:          v.Before,
+		BeforeSensitive: v.BeforeSensitive,
+	}
+	return v.AsChange(change.Computed(beforeValue.ComputeChangeForType(ctyType))), true
+}
+
+func (v Value) isUnknown() bool {
+	if unknown, ok := v.Unknown.(bool); ok {
+		return unknown
+	}
+	return false
+}

internal/command/jsonformat/differ/sensitive.go

@@ -2,7 +2,7 @@ package differ
 
 import "github.com/hashicorp/terraform/internal/command/jsonformat/change"
 
-func (v Value) CheckForSensitive() (change.Change, bool) {
+func (v Value) checkForSensitive() (change.Change, bool) {
 	beforeSensitive := v.isBeforeSensitive()
 	afterSensitive := v.isAfterSensitive()
 

internal/command/jsonformat/differ/value_test.go

@@ -24,7 +24,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Create,
-			expectedReplace: false,
 			validateChange: change.ValidatePrimitive(nil, strptr("\"new\"")),
 		},
 		"primitive_delete": {
@@ -35,7 +34,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Delete,
-			expectedReplace: false,
 			validateChange: change.ValidatePrimitive(strptr("\"old\""), nil),
 		},
 		"primitive_update": {
@@ -47,7 +45,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Update,
-			expectedReplace: false,
 			validateChange: change.ValidatePrimitive(strptr("\"old\""), strptr("\"new\"")),
 		},
 		"primitive_set_explicit_null": {
@@ -60,7 +57,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Update,
-			expectedReplace: false,
 			validateChange: change.ValidatePrimitive(strptr("\"old\""), nil),
 		},
 		"primitive_unset_explicit_null": {
@@ -73,7 +69,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Update,
-			expectedReplace: false,
 			validateChange: change.ValidatePrimitive(nil, strptr("\"new\"")),
 		},
 		"primitive_create_sensitive": {
@@ -86,7 +81,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Create,
-			expectedReplace: false,
 			validateChange: change.ValidateSensitive(nil, "new", false, true),
 		},
 		"primitive_delete_sensitive": {
@@ -99,7 +93,6 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Delete,
-			expectedReplace: false,
 			validateChange: change.ValidateSensitive("old", nil, true, false),
 		},
 		"primitive_update_sensitive": {
@@ -113,9 +106,32 @@ func TestValue_Attribute(t *testing.T) {
 				AttributeType: []byte("\"string\""),
 			},
 			expectedAction: plans.Update,
-			expectedReplace: false,
 			validateChange: change.ValidateSensitive("old", "new", true, true),
 		},
+		"primitive_create_computed": {
+			input: Value{
+				Before:  nil,
+				After:   nil,
+				Unknown: true,
+			},
+			attribute: &jsonprovider.Attribute{
+				AttributeType: []byte("\"string\""),
+			},
+			expectedAction: plans.Create,
+			validateChange: change.ValidateComputed(nil),
+		},
+		"primitive_update_computed": {
+			input: Value{
+				Before:  "old",
+				After:   nil,
+				Unknown: true,
+			},
+			attribute: &jsonprovider.Attribute{
+				AttributeType: []byte("\"string\""),
+			},
+			expectedAction: plans.Update,
+			validateChange: change.ValidateComputed(change.ValidatePrimitive(strptr("\"old\""), nil)),
+		},
 	}
 	for name, tc := range tcs {
 		t.Run(name, func(t *testing.T) {