action: Add initial schema interface, attributes, and unlinked schema

action/schema.go

@@ -4,8 +4,8 @@
 package action
 
 import (
+	"github.com/hashicorp/terraform-plugin-framework/action/schema"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
-	"github.com/hashicorp/terraform-plugin-framework/internal/fwschema"
 )
 
 // SchemaRequest represents a request for the Action to return its schema.
@@ -17,10 +17,15 @@ type SchemaRequest struct{}
 // response struct is supplied as an argument to the Action type Schema
 // method.
 type SchemaResponse struct {
-	// TODO:Actions: This will eventually be replaced by an interface defined in
-	// an "actions/schema" package. Schema implementations that will fulfill this
-	// interface will be unlinked, linked, or lifecycle. (also defined in the "actions/schema" package)
-	Schema fwschema.Schema
+
+	// Schema is the schema of the action.
+	//
+	// There are three different types of actions, which define how a practitioner can trigger an action,
+	// as well as what effect the action can have on the state.
+	//   - [schema.UnlinkedSchema] actions are actions that cannot cause changes to resource states.
+	//   - [schema.LifecycleSchema] actions are actions that can cause changes to exactly one resource state.
+	//   - [schema.LinkedSchema] actions are actions that can cause changes to one or more resource states.
+	Schema schema.SchemaType
 
 	// Diagnostics report errors or warnings related to retrieving the action schema.
 	// An empty slice indicates success, with no warnings or errors generated.

action/schema/attribute.go

@@ -0,0 +1,52 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package schema
+
+import (
+	"github.com/hashicorp/terraform-plugin-framework/internal/fwschema"
+)
+
+// TODO:Actions: Add all of the attribute and nested attribute types listed below
+//
+// Attribute define a value field inside an action type schema. Implementations in this
+// package include:
+//   - BoolAttribute
+//   - DynamicAttribute
+//   - Float32Attribute
+//   - Float64Attribute
+//   - Int32Attribute
+//   - Int64Attribute
+//   - ListAttribute
+//   - MapAttribute
+//   - NumberAttribute
+//   - ObjectAttribute
+//   - SetAttribute
+//   - StringAttribute
+//
+// Additionally, the NestedAttribute interface extends Attribute with nested
+// attributes. Only supported in protocol version 6. Implementations in this
+// package include:
+//   - ListNestedAttribute
+//   - MapNestedAttribute
+//   - SetNestedAttribute
+//   - SingleNestedAttribute
+//
+// In practitioner configurations, an equals sign (=) is required to set
+// the value. [Configuration Reference]
+//
+// [Configuration Reference]: https://developer.hashicorp.com/terraform/language/syntax/configuration
+type Attribute interface {
+	fwschema.Attribute
+}
+
+// schemaAttributes is an action attribute to fwschema type conversion function.
+func schemaAttributes(attributes map[string]Attribute) map[string]fwschema.Attribute {
+	result := make(map[string]fwschema.Attribute, len(attributes))
+
+	for name, attribute := range attributes {
+		result[name] = attribute
+	}
+
+	return result
+}

action/schema/block.go

@@ -0,0 +1,43 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package schema
+
+import (
+	"github.com/hashicorp/terraform-plugin-framework/internal/fwschema"
+)
+
+// TODO:Actions: Add all of the block and nested block types listed below
+//
+// Block defines a structural field inside an action type schema. Implementations in this
+// package include:
+//   - ListNestedBlock
+//   - SetNestedBlock
+//   - SingleNestedBlock
+//
+// In practitioner configurations, an equals sign (=) cannot be used to set the
+// value. Blocks are instead repeated as necessary, or require the use of
+// [Dynamic Block Expressions].
+//
+// Prefer NestedAttribute over Block. Blocks should typically be used for
+// configuration compatibility with previously existing schemas from an older
+// Terraform Plugin SDK. Efforts should be made to convert from Block to
+// NestedAttribute as a breaking change for practitioners.
+//
+// [Dynamic Block Expressions]: https://developer.hashicorp.com/terraform/language/expressions/dynamic-blocks
+//
+// [Configuration Reference]: https://developer.hashicorp.com/terraform/language/syntax/configuration
+type Block interface {
+	fwschema.Block
+}
+
+// schemaBlocks is an action block to fwschema type conversion function.
+func schemaBlocks(blocks map[string]Block) map[string]fwschema.Block {
+	result := make(map[string]fwschema.Block, len(blocks))
+
+	for name, block := range blocks {
+		result[name] = block
+	}
+
+	return result
+}

action/schema/bool_attribute.go

@@ -0,0 +1,170 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package schema
+
+import (
+	"github.com/hashicorp/terraform-plugin-go/tftypes"
+
+	"github.com/hashicorp/terraform-plugin-framework/attr"
+	"github.com/hashicorp/terraform-plugin-framework/internal/fwschema"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
+)
+
+// Ensure the implementation satisfies the desired interfaces.
+var (
+	_ Attribute = BoolAttribute{}
+)
+
+// BoolAttribute represents a schema attribute that is a boolean. When
+// retrieving the value for this attribute, use types.Bool as the value type
+// unless the CustomType field is set.
+//
+// Terraform configurations configure this attribute using expressions that
+// return a boolean or directly via the true/false keywords.
+//
+//	example_attribute = true
+//
+// Terraform configurations reference this attribute using the attribute name.
+//
+//	.example_attribute
+type BoolAttribute struct {
+	// CustomType enables the use of a custom attribute type in place of the
+	// default basetypes.BoolType. When retrieving data, the basetypes.BoolValuable
+	// associated with this custom type must be used in place of types.Bool.
+	CustomType basetypes.BoolTypable
+
+	// Required indicates whether the practitioner must enter a value for
+	// this attribute or not. Required and Optional cannot both be true,
+	// and Required and Computed cannot both be true.
+	Required bool
+
+	// Optional indicates whether the practitioner can choose to enter a value
+	// for this attribute or not. Optional and Required cannot both be true.
+	Optional bool
+
+	// Description is used in various tooling, like the language server, to
+	// give practitioners more information about what this attribute is,
+	// what it's for, and how it should be used. It should be written as
+	// plain text, with no special formatting.
+	Description string
+
+	// MarkdownDescription is used in various tooling, like the
+	// documentation generator, to give practitioners more information
+	// about what this attribute is, what it's for, and how it should be
+	// used. It should be formatted using Markdown.
+	MarkdownDescription string
+
+	// DeprecationMessage defines warning diagnostic details to display when
+	// practitioner configurations use this Attribute. The warning diagnostic
+	// summary is automatically set to "Attribute Deprecated" along with
+	// configuration source file and line information.
+	//
+	// Set this field to a practitioner actionable message such as:
+	//
+	//  - "Configure other_attribute instead. This attribute will be removed
+	//    in the next major version of the provider."
+	//  - "Remove this attribute's configuration as it no longer is used and
+	//    the attribute will be removed in the next major version of the
+	//    provider."
+	//
+	// In Terraform 1.2.7 and later, this warning diagnostic is displayed any
+	// time a practitioner attempts to configure a value for this attribute and
+	// certain scenarios where this attribute is referenced.
+	//
+	// In Terraform 1.2.6 and earlier, this warning diagnostic is only
+	// displayed when the Attribute is Required or Optional, and if the
+	// practitioner configuration sets the value to a known or unknown value
+	// (which may eventually be null).
+	//
+	// Across any Terraform version, there are no warnings raised for
+	// practitioner configuration values set directly to null, as there is no
+	// way for the framework to differentiate between an unset and null
+	// configuration due to how Terraform sends configuration information
+	// across the protocol.
+	//
+	// Additional information about deprecation enhancements for read-only
+	// attributes can be found in:
+	//
+	//  - https://github.com/hashicorp/terraform/issues/7569
+	//
+	DeprecationMessage string
+}
+
+// ApplyTerraform5AttributePathStep always returns an error as it is not
+// possible to step further into a BoolAttribute.
+func (a BoolAttribute) ApplyTerraform5AttributePathStep(step tftypes.AttributePathStep) (interface{}, error) {
+	return a.GetType().ApplyTerraform5AttributePathStep(step)
+}
+
+// Equal returns true if the given Attribute is a BoolAttribute
+// and all fields are equal.
+func (a BoolAttribute) Equal(o fwschema.Attribute) bool {
+	if _, ok := o.(BoolAttribute); !ok {
+		return false
+	}
+
+	return fwschema.AttributesEqual(a, o)
+}
+
+// GetDeprecationMessage returns the DeprecationMessage field value.
+func (a BoolAttribute) GetDeprecationMessage() string {
+	return a.DeprecationMessage
+}
+
+// GetDescription returns the Description field value.
+func (a BoolAttribute) GetDescription() string {
+	return a.Description
+}
+
+// GetMarkdownDescription returns the MarkdownDescription field value.
+func (a BoolAttribute) GetMarkdownDescription() string {
+	return a.MarkdownDescription
+}
+
+// GetType returns types.StringType or the CustomType field value if defined.
+func (a BoolAttribute) GetType() attr.Type {
+	if a.CustomType != nil {
+		return a.CustomType
+	}
+
+	return types.BoolType
+}
+
+// IsComputed always returns false as action schema attributes cannot be Computed.
+func (a BoolAttribute) IsComputed() bool {
+	return false
+}
+
+// IsOptional returns the Optional field value.
+func (a BoolAttribute) IsOptional() bool {
+	return a.Optional
+}
+
+// IsRequired returns the Required field value.
+func (a BoolAttribute) IsRequired() bool {
+	return a.Required
+}
+
+// IsSensitive always returns false as action schema attributes cannot be Sensitive.
+func (a BoolAttribute) IsSensitive() bool {
+	return false
+}
+
+// IsWriteOnly always returns false as action schema attributes cannot be WriteOnly.
+func (a BoolAttribute) IsWriteOnly() bool {
+	return false
+}
+
+// IsRequiredForImport returns false as this behavior is only relevant
+// for managed resource identity schema attributes.
+func (a BoolAttribute) IsRequiredForImport() bool {
+	return false
+}
+
+// IsOptionalForImport returns false as this behavior is only relevant
+// for managed resource identity schema attributes.
+func (a BoolAttribute) IsOptionalForImport() bool {
+	return false
+}