simple provider for internal testing

Simple is a minimal provider implementation using the grpcwrap package,
intended for use in internal tests.

internal/provider-simple/main/main.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"github.com/hashicorp/terraform/internal/grpcwrap"
+	simple "github.com/hashicorp/terraform/internal/provider-simple"
+	"github.com/hashicorp/terraform/internal/tfplugin5"
+	"github.com/hashicorp/terraform/plugin"
+)
+
+func main() {
+	plugin.Serve(&plugin.ServeOpts{
+		GRPCProviderFunc: func() tfplugin5.ProviderServer {
+			return grpcwrap.New(simple.Provider())
+		},
+	})
+}

internal/provider-simple/provider.go

@@ -0,0 +1,128 @@
+// 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
+}