Implement comparison state checks to replace `TestCheckResourceAttrPt…

…r`, `TestCheckResourceAttrPair` and `TestCheckTypeSetElemAttrPair` (#330) * compare: Add compare package and implementations for ValuesSame, ValuesSameAny, ValuesDiffer, ValuesDifferAny, and ValuesDifferAll * statecheck: Add CompareValue, CompareValueContains, and CompareValuePairs state checks * statecheck: Fixing references in tests * Adding go docs and constructor to compare package types * Adding go docs for CompareValue state checks * Refactoring ValueComparer implementations to handle slice and map of interface values * Refactoring CompareValueCollection to extract nested values * Adding further test coverage for CompareValueCollection * Adding compare pkg doc * Removing ValuesDifferAll, ValuesDifferAny, ValuesSameAny * Adding website docs for value comparers and compare value state checks * Amending docs for known value checks * build(deps): Bump hashicorp/setup-terraform from 3.1.0 to 3.1.1 (#335) Bumps [hashicorp/setup-terraform](https://github.com/hashicorp/setup-terraform) from 3.1.0 to 3.1.1. - [Release notes](https://github.com/hashicorp/setup-terraform/releases) - [Changelog](https://github.com/hashicorp/setup-terraform/blob/main/CHANGELOG.md) - [Commits](hashicorp/setup-terraform@97f030c...651471c) --- updated-dependencies: - dependency-name: hashicorp/setup-terraform dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * build(deps): Bump hashicorp/setup-copywrite from 1.1.2 to 1.1.3 (#336) Bumps [hashicorp/setup-copywrite](https://github.com/hashicorp/setup-copywrite) from 1.1.2 to 1.1.3. - [Release notes](https://github.com/hashicorp/setup-copywrite/releases) - [Commits](hashicorp/setup-copywrite@867a1a2...32638da) --- updated-dependencies: - dependency-name: hashicorp/setup-copywrite dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Result of tsccr-helper -log-level=info gha update -latest . (#337) Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> * build(deps): Bump github.com/hashicorp/terraform-json (#338) Bumps [github.com/hashicorp/terraform-json](https://github.com/hashicorp/terraform-json) from 0.21.0 to 0.22.0. - [Release notes](https://github.com/hashicorp/terraform-json/releases) - [Commits](hashicorp/terraform-json@v0.21.0...v0.22.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/terraform-json dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * build(deps): Bump github.com/hashicorp/terraform-json (#339) Bumps [github.com/hashicorp/terraform-json](https://github.com/hashicorp/terraform-json) from 0.22.0 to 0.22.1. - [Release notes](https://github.com/hashicorp/terraform-json/releases) - [Commits](hashicorp/terraform-json@v0.22.0...v0.22.1) --- updated-dependencies: - dependency-name: github.com/hashicorp/terraform-json dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * build(deps): Bump github.com/hashicorp/terraform-exec (#341) Bumps [github.com/hashicorp/terraform-exec](https://github.com/hashicorp/terraform-exec) from 0.20.0 to 0.21.0. - [Release notes](https://github.com/hashicorp/terraform-exec/releases) - [Changelog](https://github.com/hashicorp/terraform-exec/blob/main/CHANGELOG.md) - [Commits](hashicorp/terraform-exec@v0.20.0...v0.21.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/terraform-exec dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * all: Add deferred action testing support (plan checks, version check, and CLI options) (#331) * sloppy first commit! * add version checks and tests * add changelogs * update terraform-plugin-go * spelling fix * update `terraform-json` * switch to pointer bool value * Update changelog * [CI] Update issue comment triage workflow file * [CI] Update issue comment triage workflow file * [CI] Update issue comment triage workflow file * [CI] Update issue comment triage workflow file * Result of tsccr-helper -log-level=info gha update -latest . (#342) Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> * build(deps): Bump github.com/hashicorp/terraform-plugin-sdk/v2 (#343) Bumps [github.com/hashicorp/terraform-plugin-sdk/v2](https://github.com/hashicorp/terraform-plugin-sdk) from 2.33.0 to 2.34.0. - [Release notes](https://github.com/hashicorp/terraform-plugin-sdk/releases) - [Changelog](https://github.com/hashicorp/terraform-plugin-sdk/blob/main/CHANGELOG.md) - [Commits](hashicorp/terraform-plugin-sdk@v2.33.0...v2.34.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/terraform-plugin-sdk/v2 dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * workflows: Delete old issue label remove workflow (#344) Replaced by `.github/workflows/issue-comment-triage.yml` * build(deps): Bump github.com/hashicorp/hc-install from 0.6.4 to 0.7.0 (#345) updated-dependencies: - dependency-name: github.com/hashicorp/hc-install dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * [CI] Update lock workflow file * build(deps): Bump github.com/hashicorp/go-version from 1.6.0 to 1.7.0 (#346) Bumps [github.com/hashicorp/go-version](https://github.com/hashicorp/go-version) from 1.6.0 to 1.7.0. - [Release notes](https://github.com/hashicorp/go-version/releases) - [Changelog](https://github.com/hashicorp/go-version/blob/main/CHANGELOG.md) - [Commits](hashicorp/go-version@v1.6.0...v1.7.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/go-version dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Result of tsccr-helper -log-level=info gha update -latest . (#348) Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * build(deps): Bump golang.org/x/crypto from 0.23.0 to 0.24.0 (#350) Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.23.0 to 0.24.0. - [Commits](golang/crypto@v0.23.0...v0.24.0) --- updated-dependencies: - dependency-name: golang.org/x/crypto dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * [CI] Update lock workflow file * build(deps): Bump github.com/hashicorp/hcl/v2 from 2.20.1 to 2.21.0 (#352) Bumps [github.com/hashicorp/hcl/v2](https://github.com/hashicorp/hcl) from 2.20.1 to 2.21.0. - [Release notes](https://github.com/hashicorp/hcl/releases) - [Changelog](https://github.com/hashicorp/hcl/blob/main/CHANGELOG.md) - [Commits](hashicorp/hcl@v2.20.1...v2.21.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/hcl/v2 dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * SEC-090: Automated trusted workflow pinning (2024-06-17) (#351) * Result of tsccr-helper -log-level=info gha update -latest . * Add version to .goreleaser file --------- Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> Co-authored-by: Austin Valle <[email protected]> * build(deps): Bump github.com/hashicorp/copywrite in /tools (#355) Bumps [github.com/hashicorp/copywrite](https://github.com/hashicorp/copywrite) from 0.18.0 to 0.19.0. - [Release notes](https://github.com/hashicorp/copywrite/releases) - [Changelog](https://github.com/hashicorp/copywrite/blob/main/.goreleaser.yaml) - [Commits](hashicorp/copywrite@v0.18.0...v0.19.0) --- updated-dependencies: - dependency-name: github.com/hashicorp/copywrite dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Result of tsccr-helper -log-level=info gha update -latest . (#354) Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> Co-authored-by: Austin Valle <[email protected]> * knownvalue: Add `Int32Exact` and `Float32Exact` checks (#356) * Add `float32exact` and `int32exact` types * Update website documentation * Add changelog entries * Update changelog wording * build(deps): Bump golang.org/x/crypto from 0.24.0 to 0.25.0 (#358) Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.24.0 to 0.25.0. - [Commits](golang/crypto@v0.24.0...v0.25.0) --- updated-dependencies: - dependency-name: golang.org/x/crypto dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> * Update changelog * all: Add deferred action testing support (plan checks, version check, and CLI options) (#331) * sloppy first commit! * add version checks and tests * add changelogs * update terraform-plugin-go * spelling fix * update `terraform-json` * switch to pointer bool value * Update changelog * [CI] terraform-devex-repos automation * [CI] terraform-devex-repos automation * knownvalue: Add `Int32Exact` and `Float32Exact` checks (#356) * Add `float32exact` and `int32exact` types * Update website documentation * Add changelog entries * Update changelog wording * Update changelog * quick doc fix * added invalid test case * adjust compare value collection to work with nested attributes * add changelogs * add tfversion skip for protov6 * update example for value comparers --------- Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: hashicorp-tsccr[bot] <129506189+hashicorp-tsccr[bot]@users.noreply.github.com> Co-authored-by: hashicorp-tsccr[bot] <hashicorp-tsccr[bot]@users.noreply.github.com> Co-authored-by: Austin Valle <[email protected]> Co-authored-by: hc-github-team-tf-provider-devex <[email protected]> Co-authored-by: Service Account - Terraform Provider DevEx <100357958+hc-github-team-tf-provider-devex@users.noreply.github.com> Co-authored-by: Selena Goods <[email protected]>
hashicorp · Aug 8, 2024 · 5d78aa4 · 5d78aa4
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diff --git a/.changes/unreleased/FEATURES-20240717-155731.yaml b/.changes/unreleased/FEATURES-20240717-155731.yaml
@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'compare: Introduced new `compare` package, which contains interfaces and implementations
+  for value comparisons in state checks.'
+time: 2024-07-17T15:57:31.637692-04:00
+custom:
+  Issue: "330"
diff --git a/.changes/unreleased/FEATURES-20240717-160116.yaml b/.changes/unreleased/FEATURES-20240717-160116.yaml
@@ -0,0 +1,6 @@
+kind: FEATURES
+body: 'statecheck: Added `CompareValue` state check, which compares sequential values of the
+  specified attribute at the given managed resource, or data source, using the supplied value comparer.'
+time: 2024-07-17T16:01:16.194665-04:00
+custom:
+  Issue: "330"
diff --git a/.changes/unreleased/FEATURES-20240717-160331.yaml b/.changes/unreleased/FEATURES-20240717-160331.yaml
@@ -0,0 +1,7 @@
+kind: FEATURES
+body: 'statecheck: Added `CompareValueCollection` state check, which compares each item in
+  the specified collection (e.g., list, set) attribute, with the second specified
+  attribute at the given managed resources, or data sources, using the supplied value comparer.'
+time: 2024-07-17T16:03:31.77827-04:00
+custom:
+  Issue: "330"
diff --git a/.changes/unreleased/FEATURES-20240717-164418.yaml b/.changes/unreleased/FEATURES-20240717-164418.yaml
@@ -0,0 +1,7 @@
+kind: FEATURES
+body: 'statecheck: Added `CompareValuePairs` state check, which compares the
+  specified attributes at the given managed resources, or data sources, using
+  the supplied value comparer.'
+time: 2024-07-17T16:44:18.612874-04:00
+custom:
+  Issue: "330"
diff --git a/.changes/unreleased/NOTES-20240717-155810.yaml b/.changes/unreleased/NOTES-20240717-155810.yaml
@@ -0,0 +1,6 @@
+kind: NOTES
+body: 'compare: The `compare` package is considered experimental and may be altered
+  or removed in a subsequent release'
+time: 2024-07-17T15:58:10.435384-04:00
+custom:
+  Issue: "330"
diff --git a/.changes/unreleased/NOTES-20240717-164911.yaml b/.changes/unreleased/NOTES-20240717-164911.yaml
@@ -0,0 +1,7 @@
+kind: NOTES
+body: 'statecheck: `CompareValue`, `CompareValueCollection`, and `CompareValuePairs`
+  state checks are considered experimental and may be altered or removed in a subsequent
+  release.'
+time: 2024-07-17T16:49:11.296585-04:00
+custom:
+  Issue: "330"
diff --git a/compare/doc.go b/compare/doc.go
@@ -0,0 +1,5 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+// Package compare contains the value comparer interface, and types implementing the value comparer interface.
+package compare
diff --git a/compare/value_comparer.go b/compare/value_comparer.go
@@ -0,0 +1,13 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package compare
+
+// ValueComparer defines an interface that is implemented to run comparison logic on multiple values. Individual
+// implementations determine how the comparison is performed (e.g., values differ, values equal).
+type ValueComparer interface {
+	// CompareValues should assert the given known values against any expectations.
+	// Values are always ordered in the order they were added. Use the error
+	// return to signal unexpected values or implementation errors.
+	CompareValues(values ...any) error
+}
diff --git a/compare/values_differ.go b/compare/values_differ.go
@@ -0,0 +1,31 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package compare
+
+import (
+	"fmt"
+	"reflect"
+)
+
+var _ ValueComparer = valuesDiffer{}
+
+type valuesDiffer struct{}
+
+// CompareValues determines whether each value in the sequence of the supplied values
+// differs from the preceding value.
+func (v valuesDiffer) CompareValues(values ...any) error {
+	for i := 1; i < len(values); i++ {
+		if reflect.DeepEqual(values[i-1], values[i]) {
+			return fmt.Errorf("expected values to differ, but they are the same: %v == %v", values[i-1], values[i])
+		}
+	}
+
+	return nil
+}
+
+// ValuesDiffer returns a ValueComparer for asserting that each value in the sequence of
+// the values supplied to the CompareValues method differs from the preceding value.
+func ValuesDiffer() valuesDiffer {
+	return valuesDiffer{}
+}
diff --git a/compare/values_differ_test.go b/compare/values_differ_test.go
@@ -0,0 +1,62 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package compare_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/hashicorp/terraform-plugin-testing/compare"
+)
+
+func TestValuesDiffer_CompareValues(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		in            []any
+		expectedError error
+	}{
+		"nil": {},
+		"single-value": {
+			in: []any{"str"},
+		},
+		"non-matching-sequential-values": {
+			in: []any{"str", "other_str", "str"},
+		},
+		"matching-values-string": {
+			in:            []any{"str", "other_str", "other_str"},
+			expectedError: fmt.Errorf("expected values to differ, but they are the same: other_str == other_str"),
+		},
+		"matching-values-slice": {
+			in: []any{
+				[]any{"other_str"},
+				[]any{"other_str"},
+			},
+			expectedError: fmt.Errorf("expected values to differ, but they are the same: [other_str] == [other_str]"),
+		},
+		"matching-values-map": {
+			in: []any{
+				map[string]any{"a": "other_str"},
+				map[string]any{"a": "other_str"},
+			},
+			expectedError: fmt.Errorf("expected values to differ, but they are the same: map[a:other_str] == map[a:other_str]"),
+		},
+	}
+
+	for name, testCase := range testCases {
+		name, testCase := name, testCase
+
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			err := compare.ValuesDiffer().CompareValues(testCase.in...)
+
+			if diff := cmp.Diff(err, testCase.expectedError, equateErrorMessage); diff != "" {
+				t.Errorf("unexpected difference: %s", diff)
+			}
+		})
+	}
+}
diff --git a/compare/values_same.go b/compare/values_same.go
@@ -0,0 +1,31 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package compare
+
+import (
+	"fmt"
+	"reflect"
+)
+
+var _ ValueComparer = valuesSame{}
+
+type valuesSame struct{}
+
+// CompareValues determines whether each value in the sequence of the supplied values
+// is the same as the preceding value.
+func (v valuesSame) CompareValues(values ...any) error {
+	for i := 1; i < len(values); i++ {
+		if !reflect.DeepEqual(values[i-1], values[i]) {
+			return fmt.Errorf("expected values to be the same, but they differ: %v != %v", values[i-1], values[i])
+		}
+	}
+
+	return nil
+}
+
+// ValuesSame returns a ValueComparer for asserting that each value in the sequence of
+// the values supplied to the CompareValues method is the same as the preceding value.
+func ValuesSame() valuesSame {
+	return valuesSame{}
+}
diff --git a/compare/values_same_test.go b/compare/values_same_test.go
@@ -0,0 +1,73 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package compare_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/hashicorp/terraform-plugin-testing/compare"
+)
+
+func TestValuesSame_CompareValues(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		in            []any
+		expectedError error
+	}{
+		"nil": {},
+		"single-value": {
+			in: []any{"str"},
+		},
+		"matching-values": {
+			in: []any{"str", "str", "str"},
+		},
+		"non-matching-values-string": {
+			in:            []any{"str", "str", "other_str"},
+			expectedError: fmt.Errorf("expected values to be the same, but they differ: str != other_str"),
+		},
+		"non-matching-values-slice": {
+			in: []any{
+				[]any{"str"},
+				[]any{"str"},
+				[]any{"other_str"},
+			},
+			expectedError: fmt.Errorf("expected values to be the same, but they differ: [str] != [other_str]"),
+		},
+		"non-matching-values-map": {
+			in: []any{
+				map[string]any{"a": "str"},
+				map[string]any{"a": "str"},
+				map[string]any{"a": "other_str"},
+			},
+			expectedError: fmt.Errorf("expected values to be the same, but they differ: map[a:str] != map[a:other_str]"),
+		},
+	}
+
+	for name, testCase := range testCases {
+		name, testCase := name, testCase
+
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			err := compare.ValuesSame().CompareValues(testCase.in...)
+
+			if diff := cmp.Diff(err, testCase.expectedError, equateErrorMessage); diff != "" {
+				t.Errorf("unexpected difference: %s", diff)
+			}
+		})
+	}
+}
+
+// equateErrorMessage reports errors to be equal if both are nil
+// or both have the same message.
+var equateErrorMessage = cmp.Comparer(func(x, y error) bool {
+	if x == nil || y == nil {
+		return x == nil && y == nil
+	}
+	return x.Error() == y.Error()
+})
diff --git a/statecheck/compare_value.go b/statecheck/compare_value.go
@@ -0,0 +1,114 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package statecheck
+
+import (
+	"context"
+	"fmt"
+
+	tfjson "github.com/hashicorp/terraform-json"
+
+	"github.com/hashicorp/terraform-plugin-testing/compare"
+	"github.com/hashicorp/terraform-plugin-testing/tfjsonpath"
+)
+
+// Resource State Check
+var _ StateCheck = &compareValue{}
+
+type compareValue struct {
+	resourceAddresses []string
+	attributePaths    []tfjsonpath.Path
+	stateValues       []any
+	comparer          compare.ValueComparer
+}
+
+func (e *compareValue) AddStateValue(resourceAddress string, attributePath tfjsonpath.Path) StateCheck {
+	e.resourceAddresses = append(e.resourceAddresses, resourceAddress)
+	e.attributePaths = append(e.attributePaths, attributePath)
+
+	return e
+}
+
+// CheckState implements the state check logic.
+func (e *compareValue) CheckState(ctx context.Context, req CheckStateRequest, resp *CheckStateResponse) {
+	var resource *tfjson.StateResource
+
+	if req.State == nil {
+		resp.Error = fmt.Errorf("state is nil")
+
+		return
+	}
+
+	if req.State.Values == nil {
+		resp.Error = fmt.Errorf("state does not contain any state values")
+
+		return
+	}
+
+	if req.State.Values.RootModule == nil {
+		resp.Error = fmt.Errorf("state does not contain a root module")
+
+		return
+	}
+
+	// All calls to AddStateValue occur before any TestStep is run, populating the resourceAddresses
+	// and attributePaths slices. The stateValues slice is populated during execution of each TestStep.
+	// Each call to CheckState happens sequentially during each TestStep.
+	// The currentIndex is reflective of the current state value being checked.
+	currentIndex := len(e.stateValues)
+
+	if len(e.resourceAddresses) <= currentIndex {
+		resp.Error = fmt.Errorf("resource addresses index out of bounds: %d", currentIndex)
+
+		return
+	}
+
+	resourceAddress := e.resourceAddresses[currentIndex]
+
+	for _, r := range req.State.Values.RootModule.Resources {
+		if resourceAddress == r.Address {
+			resource = r
+
+			break
+		}
+	}
+
+	if resource == nil {
+		resp.Error = fmt.Errorf("%s - Resource not found in state", resourceAddress)
+
+		return
+	}
+
+	if len(e.attributePaths) <= currentIndex {
+		resp.Error = fmt.Errorf("attribute paths index out of bounds: %d", currentIndex)
+
+		return
+	}
+
+	attributePath := e.attributePaths[currentIndex]
+
+	result, err := tfjsonpath.Traverse(resource.AttributeValues, attributePath)
+
+	if err != nil {
+		resp.Error = err
+
+		return
+	}
+
+	e.stateValues = append(e.stateValues, result)
+
+	err = e.comparer.CompareValues(e.stateValues...)
+
+	if err != nil {
+		resp.Error = err
+	}
+}
+
+// CompareValue returns a state check that compares values retrieved from state using the
+// supplied value comparer.
+func CompareValue(comparer compare.ValueComparer) *compareValue {
+	return &compareValue{
+		comparer: comparer,
+	}
+}