terraform/internal/provider-simple/provider.go

// simple provider a minimal provider implementation for testing
package simple

import (
	"errors"
	"time"

	"github.com/hashicorp/terraform/configs/configschema"
	"github.com/hashicorp/terraform/providers"
	"github.com/zclconf/go-cty/cty"
	ctyjson "github.com/zclconf/go-cty/cty/json"
)

type simple struct {
	schema providers.GetSchemaResponse
}

func Provider() providers.Interface {
	simpleResource := providers.Schema{
		Block: &configschema.Block{
			Attributes: map[string]*configschema.Attribute{
				"id": {
					Computed: true,
					Type:     cty.String,
				},
				"value": {
					Optional: true,
					Type:     cty.String,
				},
			},
		},
	}

	return simple{
		schema: providers.GetSchemaResponse{
			Provider: providers.Schema{
				Block: nil,
			},
			ResourceTypes: map[string]providers.Schema{
				"simple_resource": simpleResource,
			},
			DataSources: map[string]providers.Schema{
				"simple_resource": simpleResource,
			},
		},
	}
}

func (s simple) GetSchema() providers.GetSchemaResponse {
	return s.schema
}

func (s simple) PrepareProviderConfig(req providers.PrepareProviderConfigRequest) (resp providers.PrepareProviderConfigResponse) {
	return resp
}

func (s simple) ValidateResourceTypeConfig(req providers.ValidateResourceTypeConfigRequest) (resp providers.ValidateResourceTypeConfigResponse) {
	return resp
}

func (s simple) ValidateDataSourceConfig(req providers.ValidateDataSourceConfigRequest) (resp providers.ValidateDataSourceConfigResponse) {
	return resp
}

func (p simple) UpgradeResourceState(req providers.UpgradeResourceStateRequest) (resp providers.UpgradeResourceStateResponse) {
	ty := p.schema.ResourceTypes[req.TypeName].Block.ImpliedType()
	val, err := ctyjson.Unmarshal(req.RawStateJSON, ty)
	resp.Diagnostics = resp.Diagnostics.Append(err)
	resp.UpgradedState = val
	return resp
}

func (s simple) Configure(providers.ConfigureRequest) (resp providers.ConfigureResponse) {
	return resp
}

func (s simple) Stop() error {
	return nil
}

func (s simple) ReadResource(req providers.ReadResourceRequest) (resp providers.ReadResourceResponse) {
	// just return the same state we received
	resp.NewState = req.PriorState
	return resp
}

func (s simple) PlanResourceChange(req providers.PlanResourceChangeRequest) (resp providers.PlanResourceChangeResponse) {
	m := req.ProposedNewState.AsValueMap()
	_, ok := m["id"]
	if !ok {
		m["id"] = cty.UnknownVal(cty.String)
	}

	resp.PlannedState = cty.ObjectVal(m)
	return resp
}

func (s simple) ApplyResourceChange(req providers.ApplyResourceChangeRequest) (resp providers.ApplyResourceChangeResponse) {
	if req.PlannedState.IsNull() {
		resp.NewState = req.PlannedState
		return resp
	}

	m := req.PlannedState.AsValueMap()
	_, ok := m["id"]
	if !ok {
		m["id"] = cty.StringVal(time.Now().String())
	}
	resp.NewState = cty.ObjectVal(m)

	return resp
}

func (s simple) ImportResourceState(providers.ImportResourceStateRequest) (resp providers.ImportResourceStateResponse) {
	resp.Diagnostics = resp.Diagnostics.Append(errors.New("unsupported"))
	return resp
}

func (s simple) ReadDataSource(req providers.ReadDataSourceRequest) (resp providers.ReadDataSourceResponse) {
	m := req.Config.AsValueMap()
	m["id"] = cty.StringVal("static_id")
	resp.State = cty.ObjectVal(m)
	return resp
}

func (s simple) Close() error {
	return nil
}