helper/resource: Add new StateStore test mode for smoke testing Terraform state storage

.changes/unreleased/FEATURES-20260109-170955.yaml

@@ -0,0 +1,5 @@
+kind: FEATURES
+body: 'helper/resource: Added new `StateStore` testing mode to `TestStep`, which can be used to smoke test Terraform state storage.'
+time: 2026-01-09T17:09:55.56054-05:00
+custom:
+    Issue: "591"

go.mod

@@ -11,9 +11,9 @@ require (
 	github.com/hashicorp/hc-install v0.9.2
 	github.com/hashicorp/hcl/v2 v2.24.0
 	github.com/hashicorp/logutils v1.0.0
-	github.com/hashicorp/terraform-exec v0.24.0
+	github.com/hashicorp/terraform-exec v0.24.1-0.20260121172827-e91e9600ec9b
 	github.com/hashicorp/terraform-json v0.27.2
-	github.com/hashicorp/terraform-plugin-go v0.29.0
+	github.com/hashicorp/terraform-plugin-go v0.29.1-0.20260122204301-b0a6aca80fd7
 	github.com/hashicorp/terraform-plugin-log v0.10.0
 	github.com/hashicorp/terraform-plugin-sdk/v2 v2.38.1
 	github.com/mitchellh/go-testing-interface v1.14.1
@@ -54,7 +54,7 @@ require (
 	golang.org/x/text v0.33.0 // indirect
 	golang.org/x/tools v0.40.0 // indirect
 	google.golang.org/appengine v1.6.8 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 // indirect
-	google.golang.org/grpc v1.75.1 // indirect
-	google.golang.org/protobuf v1.36.9 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda // indirect
+	google.golang.org/grpc v1.78.0 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
 )

go.sum

@@ -77,12 +77,12 @@ github.com/hashicorp/hcl/v2 v2.24.0 h1:2QJdZ454DSsYGoaE6QheQZjtKZSUs9Nh2izTWiwQx
 github.com/hashicorp/hcl/v2 v2.24.0/go.mod h1:oGoO1FIQYfn/AgyOhlg9qLC6/nOJPX3qGbkZpYAcqfM=
 github.com/hashicorp/logutils v1.0.0 h1:dLEQVugN8vlakKOUE3ihGLTZJRB4j+M2cdTm/ORI65Y=
 github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=
-github.com/hashicorp/terraform-exec v0.24.0 h1:mL0xlk9H5g2bn0pPF6JQZk5YlByqSqrO5VoaNtAf8OE=
-github.com/hashicorp/terraform-exec v0.24.0/go.mod h1:lluc/rDYfAhYdslLJQg3J0oDqo88oGQAdHR+wDqFvo4=
+github.com/hashicorp/terraform-exec v0.24.1-0.20260121172827-e91e9600ec9b h1:fJUuEi2V7XraZP/KFvfEsfG+YoszjVp1jz1wRH2g3c0=
+github.com/hashicorp/terraform-exec v0.24.1-0.20260121172827-e91e9600ec9b/go.mod h1:/+qarFaJUhdMK58b2hpaEEypGqsGPfauUuSOiengLr4=
 github.com/hashicorp/terraform-json v0.27.2 h1:BwGuzM6iUPqf9JYM/Z4AF1OJ5VVJEEzoKST/tRDBJKU=
 github.com/hashicorp/terraform-json v0.27.2/go.mod h1:GzPLJ1PLdUG5xL6xn1OXWIjteQRT2CNT9o/6A9mi9hE=
-github.com/hashicorp/terraform-plugin-go v0.29.0 h1:1nXKl/nSpaYIUBU1IG/EsDOX0vv+9JxAltQyDMpq5mU=
-github.com/hashicorp/terraform-plugin-go v0.29.0/go.mod h1:vYZbIyvxyy0FWSmDHChCqKvI40cFTDGSb3D8D70i9GM=
+github.com/hashicorp/terraform-plugin-go v0.29.1-0.20260122204301-b0a6aca80fd7 h1:ViO8kjIwBFTqOrMT5GilsY8TKRjejAqSTyFjjdTMY1o=
+github.com/hashicorp/terraform-plugin-go v0.29.1-0.20260122204301-b0a6aca80fd7/go.mod h1:q0rLI/Z8QaAhX+22MvIlGbFkHoOtwS58vaShJZPXndU=
 github.com/hashicorp/terraform-plugin-log v0.10.0 h1:eu2kW6/QBVdN4P3Ju2WiB2W3ObjkAsyfBsL3Wh1fj3g=
 github.com/hashicorp/terraform-plugin-log v0.10.0/go.mod h1:/9RR5Cv2aAbrqcTSdNmY1NRHP4E3ekrXRGjqORpXyB0=
 github.com/hashicorp/terraform-plugin-sdk/v2 v2.38.1 h1:mlAq/OrMlg04IuJT7NpefI1wwtdpWudnEmjuQs04t/4=
@@ -155,18 +155,18 @@ github.com/zclconf/go-cty v1.17.0 h1:seZvECve6XX4tmnvRzWtJNHdscMtYEx5R7bnnVyd/d0
 github.com/zclconf/go-cty v1.17.0/go.mod h1:wqFzcImaLTI6A5HfsRwB0nj5n0MRZFwmey8YoFPPs3U=
 github.com/zclconf/go-cty-debug v0.0.0-20240509010212-0d6042c53940 h1:4r45xpDWB6ZMSMNJFMOjqrGHynW3DIBuR2H9j0ug+Mo=
 github.com/zclconf/go-cty-debug v0.0.0-20240509010212-0d6042c53940/go.mod h1:CmBdvvj3nqzfzJ6nTCIwDTPZ56aVGvDrmztiO5g3qrM=
-go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
-go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
-go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
-go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
-go.opentelemetry.io/otel/metric v1.37.0 h1:mvwbQS5m0tbmqML4NqK+e3aDiO02vsf/WgbsdpcPoZE=
-go.opentelemetry.io/otel/metric v1.37.0/go.mod h1:04wGrZurHYKOc+RKeye86GwKiTb9FKm1WHtO+4EVr2E=
-go.opentelemetry.io/otel/sdk v1.37.0 h1:ItB0QUqnjesGRvNcmAcU0LyvkVyGJ2xftD29bWdDvKI=
-go.opentelemetry.io/otel/sdk v1.37.0/go.mod h1:VredYzxUvuo2q3WRcDnKDjbdvmO0sCzOvVAiY+yUkAg=
-go.opentelemetry.io/otel/sdk/metric v1.37.0 h1:90lI228XrB9jCMuSdA0673aubgRobVZFhbjxHHspCPc=
-go.opentelemetry.io/otel/sdk/metric v1.37.0/go.mod h1:cNen4ZWfiD37l5NhS+Keb5RXVWZWpRE+9WyVCpbo5ps=
-go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mxVK7z4=
-go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
+go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
+go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
+go.opentelemetry.io/otel v1.38.0 h1:RkfdswUDRimDg0m2Az18RKOsnI8UDzppJAtj01/Ymk8=
+go.opentelemetry.io/otel v1.38.0/go.mod h1:zcmtmQ1+YmQM9wrNsTGV/q/uyusom3P8RxwExxkZhjM=
+go.opentelemetry.io/otel/metric v1.38.0 h1:Kl6lzIYGAh5M159u9NgiRkmoMKjvbsKtYRwgfrA6WpA=
+go.opentelemetry.io/otel/metric v1.38.0/go.mod h1:kB5n/QoRM8YwmUahxvI3bO34eVtQf2i4utNVLr9gEmI=
+go.opentelemetry.io/otel/sdk v1.38.0 h1:l48sr5YbNf2hpCUj/FoGhW9yDkl+Ma+LrVl8qaM5b+E=
+go.opentelemetry.io/otel/sdk v1.38.0/go.mod h1:ghmNdGlVemJI3+ZB5iDEuk4bWA3GkTpW+DOoZMYBVVg=
+go.opentelemetry.io/otel/sdk/metric v1.38.0 h1:aSH66iL0aZqo//xXzQLYozmWrXxyFkBJ6qT5wthqPoM=
+go.opentelemetry.io/otel/sdk/metric v1.38.0/go.mod h1:dg9PBnW9XdQ1Hd6ZnRz689CbtrUp0wMMs9iPcgT9EZA=
+go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJrmcNLE=
+go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
@@ -221,14 +221,14 @@ gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.6.8 h1:IhEN5q69dyKagZPYMSdIjS2HqprW324FRQZJcGqPAsM=
 google.golang.org/appengine v1.6.8/go.mod h1:1jJ3jBArFh5pcgW8gCtRJnepW8FzD1V44FJffLiz/Ds=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7 h1:pFyd6EwwL2TqFf8emdthzeX+gZE1ElRq3iM8pui4KBY=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20250707201910-8d1bb00bc6a7/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
-google.golang.org/grpc v1.75.1 h1:/ODCNEuf9VghjgO3rqLcfg8fiOP0nSluljWFlDxELLI=
-google.golang.org/grpc v1.75.1/go.mod h1:JtPAzKiq4v1xcAB2hydNlWI2RnF85XXcV0mhKXr2ecQ=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda h1:i/Q+bfisr7gq6feoJnS/DlpdwEL4ihp41fvRiM3Ork0=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20251029180050-ab9386a59fda/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
+google.golang.org/grpc v1.78.0 h1:K1XZG/yGDJnzMdd/uZHAkVqJE+xIDOcmdSFZkBUicNc=
+google.golang.org/grpc v1.78.0/go.mod h1:I47qjTo4OKbMkjA/aOOwxDIiPSBofUtQUI5EfpWvW7U=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
-google.golang.org/protobuf v1.36.9 h1:w2gp2mA27hUeUzj9Ex9FBjsBm40zfaDtEWow293U7Iw=
-google.golang.org/protobuf v1.36.9/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=

helper/resource/statestore/examplecloud_statestore_test.go

@@ -0,0 +1,104 @@
+// Copyright IBM Corp. 2014, 2025
+// SPDX-License-Identifier: MPL-2.0
+
+package statestore_test
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"path/filepath"
+	"strings"
+	"testing/fstest"
+	"time"
+
+	"github.com/hashicorp/terraform-plugin-go/tfprotov6"
+	"github.com/hashicorp/terraform-plugin-testing/internal/logging"
+	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testprovider"
+	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testsdk/statestore"
+)
+
+// This state store implementation uses an in-memory map for storing state in a filesystem-like manner.
+// This only works because the terraform-plugin-testing harness keeps provider instances running
+// throughout a Go test with multiple Terraform CLI command calls by using a reattach configuration.
+func exampleCloudValidStateStore() *testprovider.StateStore {
+	memFS := fstest.MapFS{}
+
+	return &testprovider.StateStore{
+		SchemaResponse: &statestore.SchemaResponse{
+			Schema: &tfprotov6.Schema{
+				Block: &tfprotov6.SchemaBlock{Attributes: []*tfprotov6.SchemaAttribute{}},
+			},
+		},
+		GetStatesFunc: func(ctx context.Context, req statestore.GetStatesRequest, resp *statestore.GetStatesResponse) {
+			directories, err := memFS.ReadDir(".")
+			if err != nil {
+				resp.Diagnostics = append(resp.Diagnostics, &tfprotov6.Diagnostic{
+					Severity: tfprotov6.DiagnosticSeverityError,
+					Summary:  "Error reading inmem filesystem",
+					Detail:   err.Error(),
+				})
+				return
+			}
+
+			workspaces := make([]string, 0)
+			for _, dir := range directories {
+				workspaces = append(workspaces, dir.Name())
+			}
+
+			resp.StateIDs = workspaces
+		},
+		DeleteStateFunc: func(ctx context.Context, req statestore.DeleteStateRequest, resp *statestore.DeleteStateResponse) {
+			for filePath := range memFS {
+				if strings.HasPrefix(filePath, req.StateID) {
+					delete(memFS, filePath)
+				}
+			}
+		},
+		LockStateFunc: func(ctx context.Context, req statestore.LockStateRequest, resp *statestore.LockStateResponse) {
+			logging.HelperResourceDebug(ctx, "examplecloud_inmem: Lock support not implemented")
+		},
+		UnlockStateFunc: func(ctx context.Context, req statestore.UnlockStateRequest, resp *statestore.UnlockStateResponse) {
+			logging.HelperResourceDebug(ctx, "examplecloud_inmem: Lock support not implemented")
+		},
+		ReadStateBytesFunc: func(ctx context.Context, req statestore.ReadStateBytesRequest, resp *statestore.ReadStateBytesResponse) {
+			stateFilePath := filepath.Join(req.StateID, "terraform.tfstate")
+			stateFile, err := memFS.Open(stateFilePath)
+			if err != nil {
+				// If there is no state file, Terraform will create one.
+				if errors.Is(err, fs.ErrNotExist) {
+					return
+				}
+
+				resp.Diagnostics = append(resp.Diagnostics, &tfprotov6.Diagnostic{
+					Severity: tfprotov6.DiagnosticSeverityError,
+					Summary:  fmt.Sprintf("Error reading state %q at path %q", req.StateID, stateFilePath),
+					Detail:   err.Error(),
+				})
+				return
+			}
+
+			stateBytes, err := io.ReadAll(stateFile)
+			if err != nil {
+				resp.Diagnostics = append(resp.Diagnostics, &tfprotov6.Diagnostic{
+					Severity: tfprotov6.DiagnosticSeverityError,
+					Summary:  fmt.Sprintf("Error reading %q state bytes", req.StateID),
+					Detail:   err.Error(),
+				})
+				return
+			}
+
+			resp.StateBytes = stateBytes
+		},
+		WriteStateBytesFunc: func(ctx context.Context, req statestore.WriteStateBytesRequest, resp *statestore.WriteStateBytesResponse) {
+			stateFilePath := filepath.Join(req.StateID, "terraform.tfstate")
+			memFS[stateFilePath] = &fstest.MapFile{
+				Data:    req.StateBytes,
+				Mode:    fs.ModePerm,
+				ModTime: time.Now(),
+			}
+		},
+	}
+}