add ShowState, ShowPlan (#54)

* add ShowStateFile, ShowPlanFile

* e2etests for ShowStateFile, ShowPlanFile

tfexec/internal/e2etest/show_test.go

@@ -4,13 +4,15 @@ import (
 	"context"
 	"errors"
 	"reflect"
+	"runtime"
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
 	"github.com/hashicorp/go-version"
 	tfjson "github.com/hashicorp/terraform-json"
 
 	"github.com/hashicorp/terraform-exec/tfexec"
+	"github.com/hashicorp/terraform-exec/tfexec/internal/testutil"
 )
 
 var (
@@ -104,3 +106,214 @@ func TestShow_versionMismatch(t *testing.T) {
 		}
 	})
 }
+
+// Non-default state files cannot be migrated from 0.12 to 0.13,
+// so we maintain one fixture per supported version.
+// See github.com/hashicorp/terraform/25920
+func TestShowStateFile012(t *testing.T) {
+	runTestVersions(t, []string{testutil.Latest012}, "non_default_statefile_012", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		expected := tfjson.State{
+			FormatVersion:    "0.1",
+			TerraformVersion: "0.12.29",
+			Values: &tfjson.StateValues{
+				RootModule: &tfjson.StateModule{
+					Resources: []*tfjson.StateResource{{
+						Address: "null_resource.foo",
+						AttributeValues: map[string]interface{}{
+							"id":       "3610244792381545397",
+							"triggers": nil,
+						},
+						Mode:         tfjson.ManagedResourceMode,
+						Type:         "null_resource",
+						Name:         "foo",
+						ProviderName: "null",
+					}},
+				},
+			},
+		}
+
+		err := tf.Init(context.Background())
+		if err != nil {
+			t.Fatalf("error running Init in test directory: %s", err)
+		}
+
+		actual, err := tf.ShowStateFile(context.Background(), "statefilefoo")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(actual, &expected) {
+			t.Fatalf("actual: %s\nexpected: %s", spew.Sdump(actual), spew.Sdump(expected))
+		}
+	})
+}
+
+func TestShowStateFile013(t *testing.T) {
+	runTestVersions(t, []string{testutil.Latest013}, "non_default_statefile_013", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		expected := tfjson.State{
+			FormatVersion:    "0.1",
+			TerraformVersion: "0.13.0",
+			Values: &tfjson.StateValues{
+				RootModule: &tfjson.StateModule{
+					Resources: []*tfjson.StateResource{{
+						Address: "null_resource.foo",
+						AttributeValues: map[string]interface{}{
+							"id":       "3610244792381545397",
+							"triggers": nil,
+						},
+						Mode:         tfjson.ManagedResourceMode,
+						Type:         "null_resource",
+						Name:         "foo",
+						ProviderName: "registry.terraform.io/hashicorp/null",
+					}},
+				},
+			},
+		}
+
+		err := tf.Init(context.Background())
+		if err != nil {
+			t.Fatalf("error running Init in test directory: %s", err)
+		}
+
+		actual, err := tf.ShowStateFile(context.Background(), "statefilefoo")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(actual, &expected) {
+			t.Fatalf("actual: %s\nexpected: %s", spew.Sdump(actual), spew.Sdump(expected))
+		}
+	})
+}
+
+// Plan files cannot be transferred between different Terraform versions,
+// so we maintain one fixture per supported version
+func TestShowPlanFile012(t *testing.T) {
+	runTestVersions(t, []string{testutil.Latest012}, "non_default_planfile_012", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		// plan file fixture was created in Linux, and is
+		// not compatible with Windows
+		if runtime.GOOS == "windows" {
+			t.Skip("plan file created in 0.12 on Linux is not compatible with Windows")
+		}
+
+		providerName := "null"
+
+		expected := tfjson.Plan{
+			FormatVersion:    "0.1",
+			TerraformVersion: "0.12.29",
+			PlannedValues: &tfjson.StateValues{
+				RootModule: &tfjson.StateModule{
+					Resources: []*tfjson.StateResource{{
+						Address: "null_resource.foo",
+						AttributeValues: map[string]interface{}{
+							"triggers": nil,
+						},
+						Mode:         tfjson.ManagedResourceMode,
+						Type:         "null_resource",
+						Name:         "foo",
+						ProviderName: providerName,
+					}},
+				},
+			},
+			ResourceChanges: []*tfjson.ResourceChange{{
+				Address:      "null_resource.foo",
+				Mode:         tfjson.ManagedResourceMode,
+				Type:         "null_resource",
+				Name:         "foo",
+				ProviderName: providerName,
+				Change: &tfjson.Change{
+					Actions:      tfjson.Actions{tfjson.ActionCreate},
+					After:        map[string]interface{}{"triggers": nil},
+					AfterUnknown: map[string]interface{}{"id": (true)},
+				},
+			}},
+			Config: &tfjson.Config{
+				RootModule: &tfjson.ConfigModule{
+					Resources: []*tfjson.ConfigResource{{
+						Address:           "null_resource.foo",
+						Mode:              tfjson.ManagedResourceMode,
+						Type:              "null_resource",
+						Name:              "foo",
+						ProviderConfigKey: "null",
+					}},
+				},
+			},
+		}
+
+		err := tf.Init(context.Background())
+		if err != nil {
+			t.Fatalf("error running Init in test directory: %s", err)
+		}
+
+		actual, err := tf.ShowPlanFile(context.Background(), "planfilefoo")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(actual, &expected) {
+			t.Fatalf("actual: %s\nexpected: %s", spew.Sdump(actual), spew.Sdump(expected))
+		}
+	})
+}
+
+func TestShowPlanFile013(t *testing.T) {
+	runTestVersions(t, []string{testutil.Latest013}, "non_default_planfile_013", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		providerName := "registry.terraform.io/hashicorp/null"
+
+		expected := tfjson.Plan{
+			FormatVersion:    "0.1",
+			TerraformVersion: "0.13.0",
+			PlannedValues: &tfjson.StateValues{
+				RootModule: &tfjson.StateModule{
+					Resources: []*tfjson.StateResource{{
+						Address: "null_resource.foo",
+						AttributeValues: map[string]interface{}{
+							"triggers": nil,
+						},
+						Mode:         tfjson.ManagedResourceMode,
+						Type:         "null_resource",
+						Name:         "foo",
+						ProviderName: providerName,
+					}},
+				},
+			},
+			ResourceChanges: []*tfjson.ResourceChange{{
+				Address:      "null_resource.foo",
+				Mode:         tfjson.ManagedResourceMode,
+				Type:         "null_resource",
+				Name:         "foo",
+				ProviderName: providerName,
+				Change: &tfjson.Change{
+					Actions:      tfjson.Actions{tfjson.ActionCreate},
+					After:        map[string]interface{}{"triggers": nil},
+					AfterUnknown: map[string]interface{}{"id": true},
+				},
+			}},
+			Config: &tfjson.Config{
+				RootModule: &tfjson.ConfigModule{
+					Resources: []*tfjson.ConfigResource{{
+						Address:           "null_resource.foo",
+						Mode:              tfjson.ManagedResourceMode,
+						Type:              "null_resource",
+						Name:              "foo",
+						ProviderConfigKey: "null",
+					}},
+				},
+			},
+		}
+
+		err := tf.Init(context.Background())
+		if err != nil {
+			t.Fatalf("error running Init in test directory: %s", err)
+		}
+
+		actual, err := tf.ShowPlanFile(context.Background(), "planfilefoo")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !reflect.DeepEqual(actual, &expected) {
+			t.Fatalf("actual: %s\nexpected: %s", spew.Sdump(actual), spew.Sdump(expected))
+		}
+	})
+}

tfexec/internal/e2etest/testdata/non_default_planfile_012/main.tf

@@ -0,0 +1,3 @@
+resource null_resource "foo" {
+}
+

tfexec/internal/e2etest/testdata/non_default_planfile_013/main.tf

@@ -0,0 +1,3 @@
+resource null_resource "foo" {
+}
+

tfexec/internal/e2etest/testdata/non_default_statefile_012/main.tf

@@ -0,0 +1,3 @@
+resource null_resource "foo" {
+}
+

tfexec/internal/e2etest/testdata/non_default_statefile_012/statefilefoo

@@ -0,0 +1,25 @@
+{
+  "version": 4,
+  "terraform_version": "0.12.29",
+  "serial": 1,
+  "lineage": "b69e96b9-250f-2004-c603-1b11dc3459c1",
+  "outputs": {},
+  "resources": [
+    {
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "foo",
+      "provider": "provider.null",
+      "instances": [
+        {
+          "schema_version": 0,
+          "attributes": {
+            "id": "3610244792381545397",
+            "triggers": null
+          },
+          "private": "bnVsbA=="
+        }
+      ]
+    }
+  ]
+}

tfexec/internal/e2etest/testdata/non_default_statefile_013/main.tf

@@ -0,0 +1,3 @@
+resource null_resource "foo" {
+}
+

tfexec/internal/e2etest/testdata/non_default_statefile_013/statefilefoo

@@ -0,0 +1,25 @@
+{
+  "version": 4,
+  "terraform_version": "0.13.0",
+  "serial": 1,
+  "lineage": "b69e96b9-250f-2004-c603-1b11dc3459c1",
+  "outputs": {},
+  "resources": [
+    {
+      "mode": "managed",
+      "type": "null_resource",
+      "name": "foo",
+      "provider": "provider[\"registry.terraform.io/hashicorp/null\"]",
+      "instances": [
+        {
+          "schema_version": 0,
+          "attributes": {
+            "id": "3610244792381545397",
+            "triggers": null
+          },
+          "private": "bnVsbA=="
+        }
+      ]
+    }
+  ]
+}

tfexec/internal/e2etest/util_test.go

@@ -28,8 +28,6 @@ func runTest(t *testing.T, fixtureName string, cb func(t *testing.T, tfVersion *
 	}, fixtureName, cb)
 }
 
-// runTestVersions should probably not be used directly, better to use
-// t.Skip in your test with a comment as to why you shouldn't test on a version
 func runTestVersions(t *testing.T, versions []string, fixtureName string, cb func(t *testing.T, tfVersion *version.Version, tf *tfexec.Terraform)) {
 	t.Helper()
 

tfexec/show.go

@@ -10,6 +10,8 @@ import (
 	tfjson "github.com/hashicorp/terraform-json"
 )
 
+// Show reads the default state path and outputs the state.
+// To read a state or plan file, ShowState or ShowPlan must be used instead.
 func (tf *Terraform) Show(ctx context.Context) (*tfjson.State, error) {
 	err := tf.compatible(ctx, tf0_12_0, nil)
 	if err != nil {
@@ -40,6 +42,77 @@ func (tf *Terraform) Show(ctx context.Context) (*tfjson.State, error) {
 	return &ret, nil
 }
 
+// ShowStateFile reads a given state file and outputs the state.
+func (tf *Terraform) ShowStateFile(ctx context.Context, statePath string) (*tfjson.State, error) {
+	err := tf.compatible(ctx, tf0_12_0, nil)
+	if err != nil {
+		return nil, fmt.Errorf("terraform show -json was added in 0.12.0: %w", err)
+	}
+
+	if statePath == "" {
+		return nil, fmt.Errorf("statePath cannot be blank: use Show() if not passing statePath")
+	}
+
+	showCmd := tf.showCmd(ctx, statePath)
+
+	var ret tfjson.State
+	var outBuf bytes.Buffer
+	showCmd.Stdout = &outBuf
+
+	err = tf.runTerraformCmd(showCmd)
+	if err != nil {
+		return nil, err
+	}
+
+	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	if err != nil {
+		return nil, err
+	}
+
+	err = ret.Validate()
+	if err != nil {
+		return nil, err
+	}
+
+	return &ret, nil
+}
+
+// ShowPlanFile reads a given plan file and outputs the plan.
+func (tf *Terraform) ShowPlanFile(ctx context.Context, planPath string) (*tfjson.Plan, error) {
+	err := tf.compatible(ctx, tf0_12_0, nil)
+	if err != nil {
+		return nil, fmt.Errorf("terraform show -json was added in 0.12.0: %w", err)
+	}
+
+	if planPath == "" {
+		return nil, fmt.Errorf("planPath cannot be blank: use Show() if not passing planPath")
+	}
+
+	showCmd := tf.showCmd(ctx, planPath)
+
+	var ret tfjson.Plan
+	var outBuf bytes.Buffer
+	showCmd.Stdout = &outBuf
+
+	err = tf.runTerraformCmd(showCmd)
+	if err != nil {
+		return nil, err
+	}
+
+	err = json.Unmarshal(outBuf.Bytes(), &ret)
+	if err != nil {
+		return nil, err
+	}
+
+	err = ret.Validate()
+	if err != nil {
+		return nil, err
+	}
+
+	return &ret, nil
+
+}
+
 func (tf *Terraform) showCmd(ctx context.Context, args ...string) *exec.Cmd {
 	allArgs := []string{"show", "-json", "-no-color"}
 	allArgs = append(allArgs, args...)