Further specify behaviour of terraform show

CHANGELOG.md

@@ -17,6 +17,7 @@ FEATURES:
  - Add support for `graph` command [GH-257]
  - Add support for `taint` command [GH-251]
  - Add support for `untaint` command [GH-251]
+ - Add `ErrStatePlanRead`, returned when Terraform cannot read a given state or plan file [GH-273]
 
 # 0.15.0 (October 05, 2021)
 

tfexec/exit_errors.go

@@ -18,10 +18,18 @@ var (
 
 	usageRegexp = regexp.MustCompile(`Too many command line arguments|^Usage: .*Options:.*|Error: Invalid -\d+ option`)
 
-	noInitErrRegexp = regexp.MustCompile(`Error: Could not satisfy plugin requirements|` +
-		`Error: Could not load plugin|` + // v0.13
-		`Please run \"terraform init\"|` + // v1.1.0 early alpha versions (ref 89b05050)
-		`run:\s+terraform init`) // v1.1.0 (ref df578afd)
+	noInitErrRegexp = regexp.MustCompile(
+		// UNINITIALISED PROVIDERS/MODULES
+		`Error: Could not satisfy plugin requirements|` +
+			`Error: Could not load plugin|` + // v0.13
+			`Please run \"terraform init\"|` + // v1.1.0 early alpha versions (ref 89b05050)
+			`run:\s+terraform init|` + // v1.1.0 (ref df578afd)
+			`Run\s+\"terraform init\"|` + // v1.2.0
+
+			// UNINITIALISED BACKENDS
+			`Error: Initialization required.|` + // v0.13
+			`Error: Backend initialization required, please run \"terraform init\"`, // v0.15
+	)
 
 	noConfigErrRegexp = regexp.MustCompile(`Error: No configuration files`)
 
@@ -33,8 +41,11 @@ var (
 	tfVersionMismatchConstraintRegexp = regexp.MustCompile(`required_version = "(.+)"|Required version: (.+)\b`)
 	configInvalidErrRegexp            = regexp.MustCompile(`There are some problems with the configuration, described below.`)
 
-	stateLockErrRegexp  = regexp.MustCompile(`Error acquiring the state lock`)
-	stateLockInfoRegexp = regexp.MustCompile(`Lock Info:\n\s*ID:\s*([^\n]+)\n\s*Path:\s*([^\n]+)\n\s*Operation:\s*([^\n]+)\n\s*Who:\s*([^\n]+)\n\s*Version:\s*([^\n]+)\n\s*Created:\s*([^\n]+)\n`)
+	stateLockErrRegexp     = regexp.MustCompile(`Error acquiring the state lock`)
+	stateLockInfoRegexp    = regexp.MustCompile(`Lock Info:\n\s*ID:\s*([^\n]+)\n\s*Path:\s*([^\n]+)\n\s*Operation:\s*([^\n]+)\n\s*Who:\s*([^\n]+)\n\s*Version:\s*([^\n]+)\n\s*Created:\s*([^\n]+)\n`)
+	statePlanReadErrRegexp = regexp.MustCompile(
+		`Terraform couldn't read the given file as a state or plan file.|` +
+			`Error: Failed to read the given file as a state or plan file`)
 )
 
 func (tf *Terraform) wrapExitError(ctx context.Context, err error, stderr string) error {
@@ -147,6 +158,8 @@ func (tf *Terraform) wrapExitError(ctx context.Context, err error, stderr string
 				Created:   submatches[6],
 			}
 		}
+	case statePlanReadErrRegexp.MatchString(stderr):
+		return &ErrStatePlanRead{stderr: stderr}
 	}
 
 	return fmt.Errorf("%w\n%s", &unwrapper{exitErr, ctxErr}, stderr)
@@ -223,6 +236,16 @@ func (e *ErrNoInit) Error() string {
 	return e.stderr
 }
 
+type ErrStatePlanRead struct {
+	unwrapper
+
+	stderr string
+}
+
+func (e *ErrStatePlanRead) Error() string {
+	return e.stderr
+}
+
 type ErrNoConfig struct {
 	unwrapper
 

tfexec/internal/e2etest/errors_test.go

@@ -1,4 +1,5 @@
 // This file contains tests that only compile/work in Go 1.13 and forward
+//go:build go1.13
 // +build go1.13
 
 package e2etest
@@ -128,7 +129,7 @@ func TestTFVersionMismatch(t *testing.T) {
 }
 
 func TestLockedState(t *testing.T) {
-	runTest(t, "inmem-backend-locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+	runTest(t, "inmem_backend_locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
 		err := tf.Init(context.Background())
 		if err != nil {
 			t.Fatalf("err during init: %s", err)

tfexec/internal/e2etest/force_unlock_test.go

@@ -15,7 +15,7 @@ const inmemLockID = "2b6a6738-5dd5-50d6-c0ae-f6352977666b"
 var forceUnlockDirArgMaxVersion = version.Must(version.NewVersion("0.15.0"))
 
 func TestForceUnlock(t *testing.T) {
-	runTest(t, "inmem-backend-locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+	runTest(t, "inmem_backend_locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
 		err := tf.Init(context.Background())
 		if err != nil {
 			t.Fatalf("error running Init: %v", err)
@@ -26,7 +26,7 @@ func TestForceUnlock(t *testing.T) {
 			t.Fatalf("error running ForceUnlock: %v", err)
 		}
 	})
-	runTest(t, "inmem-backend-locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+	runTest(t, "inmem_backend_locked", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
 		if tfv.GreaterThanOrEqual(forceUnlockDirArgMaxVersion) {
 			t.Skip("legacy positional path argument deprecated in favor of global -chdir flag")
 		}

tfexec/internal/e2etest/show_test.go

@@ -81,8 +81,112 @@ func TestShow(t *testing.T) {
 	})
 }
 
-func TestShow_errInitRequired(t *testing.T) {
+func TestShow_emptyDir(t *testing.T) {
+	runTest(t, "empty", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		if tfv.LessThan(showMinVersion) {
+			t.Skip("terraform show was added in Terraform 0.12, so test is not valid")
+		}
+
+		formatVersion := "0.1"
+		if tfv.Core().GreaterThanOrEqual(v1_0_1) {
+			formatVersion = "0.2"
+		}
+		if tfv.Core().GreaterThanOrEqual(v1_1) {
+			formatVersion = "1.0"
+		}
+
+		expected := &tfjson.State{
+			FormatVersion: formatVersion,
+		}
+
+		actual, err := tf.Show(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if diff := diffState(expected, actual); diff != "" {
+			t.Fatalf("mismatch (-want +got):\n%s", diff)
+		}
+	})
+}
+
+func TestShow_noInitBasic(t *testing.T) {
+	// Prior to v1.2.0, running show before init always results in ErrNoInit.
+	// In the basic case, in which the local backend is implicit and there are
+	// no providers to download, this is unintended behaviour, as
+	// init is not actually necessary. This is considered a known issue in
+	// pre-1.2.0 versions.
+	runTestVersions(t, []string{testutil.Latest012, testutil.Latest013, testutil.Latest014, testutil.Latest015, testutil.Latest_v1, testutil.Latest_v1_1}, "basic", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		var noInit *tfexec.ErrNoInit
+		_, err := tf.Show(context.Background())
+		if !errors.As(err, &noInit) {
+			t.Fatalf("expected error ErrNoInit, got %T: %s", err, err)
+		}
+	})
+
+	// From v1.2.0 onwards, running show before init in the basic case returns
+	// an empty state with no error.
 	runTest(t, "basic", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		// HACK KEM: Really I mean tfv.LessThan(version.Must(version.NewVersion("1.2.0"))),
+		// but I want this test to run for refs/heads/main prior to the release of v1.2.0.
+		if tfv.LessThan(version.Must(version.NewVersion("1.2.0"))) {
+
+			t.Skip("test applies only to v1.2.0 and greater")
+		}
+		expected := &tfjson.State{
+			FormatVersion: "1.0",
+		}
+
+		actual, err := tf.Show(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if diff := diffState(expected, actual); diff != "" {
+			t.Fatalf("mismatch (-want +got):\n%s", diff)
+		}
+	})
+}
+
+func TestShow_noInitModule(t *testing.T) {
+	// Prior to v1.2.0, running show before init always results in ErrNoInit.
+	// In the basic case, in which the local backend is implicit and there are
+	// no providers to download, this is unintended behaviour, as
+	// init is not actually necessary. This is considered a known issue in
+	// pre-1.2.0 versions.
+	runTestVersions(t, []string{testutil.Latest012, testutil.Latest013, testutil.Latest014, testutil.Latest015, testutil.Latest_v1, testutil.Latest_v1_1}, "registry_module", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		var noInit *tfexec.ErrNoInit
+		_, err := tf.Show(context.Background())
+		if !errors.As(err, &noInit) {
+			t.Fatalf("expected error ErrNoInit, got %T: %s", err, err)
+		}
+	})
+
+	// From v1.2.0 onwards, running show before init in the basic case returns
+	// an empty state with no error.
+	runTest(t, "registry_module", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		// HACK KEM: Really I mean tfv.LessThan(version.Must(version.NewVersion("1.2.0"))),
+		// but I want this test to run for refs/heads/main prior to the release of v1.2.0.
+		if tfv.LessThanOrEqual(version.Must(version.NewVersion(testutil.Latest_v1_1))) {
+			t.Skip("test applies only to v1.2.0 and greater")
+		}
+		expected := &tfjson.State{
+			FormatVersion: "1.0",
+		}
+
+		actual, err := tf.Show(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if diff := diffState(expected, actual); diff != "" {
+			t.Fatalf("mismatch (-want +got):\n%s", diff)
+		}
+	})
+}
+
+func TestShow_noInitNonLocalBackend(t *testing.T) {
+	runTest(t, "inmem_backend", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
 		if tfv.LessThan(showMinVersion) {
 			t.Skip("terraform show was added in Terraform 0.12, so test is not valid")
 		}
@@ -95,6 +199,53 @@ func TestShow_errInitRequired(t *testing.T) {
 	})
 }
 
+func TestShow_noInitLocalBackendNonDefaultState(t *testing.T) {
+	runTest(t, "local_backend_non_default_state", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		if tfv.LessThan(showMinVersion) {
+			t.Skip("terraform show was added in Terraform 0.12, so test is not valid")
+		}
+
+		var noInit *tfexec.ErrNoInit
+		_, err := tf.Show(context.Background())
+		if !errors.As(err, &noInit) {
+			t.Fatalf("expected error ErrNoInit, got %T: %s", err, err)
+		}
+	})
+}
+
+func TestShow_noInitEtcdBackend(t *testing.T) {
+	runTest(t, "etcd_backend", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		if tfv.LessThan(showMinVersion) {
+			t.Skip("terraform show was added in Terraform 0.12, so test is not valid")
+		}
+
+		var noInit *tfexec.ErrNoInit
+		_, err := tf.Show(context.Background())
+		if !errors.As(err, &noInit) {
+			t.Fatalf("expected error ErrNoInit, got %T: %s", err, err)
+		}
+	})
+}
+
+func TestShow_statefileDoesNotExist(t *testing.T) {
+	runTest(t, "basic", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
+		if tfv.LessThan(showMinVersion) {
+			t.Skip("terraform show was added in Terraform 0.12, so test is not valid")
+		}
+
+		err := tf.Init(context.Background())
+		if err != nil {
+			t.Fatalf("error running Init in test directory: %s", err)
+		}
+
+		var statePlanReadErr *tfexec.ErrStatePlanRead
+		_, err = tf.ShowStateFile(context.Background(), "statefilefoo")
+		if !errors.As(err, &statePlanReadErr) {
+			t.Fatalf("expected error ErrStatePlanRead, got %T: %s", err, err)
+		}
+	})
+}
+
 func TestShow_versionMismatch(t *testing.T) {
 	runTest(t, "basic", func(t *testing.T, tfv *version.Version, tf *tfexec.Terraform) {
 		// only testing versions without show

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

@@ -0,0 +1,4 @@
+terraform {
+  backend "etcd" {
+  }
+}

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

@@ -0,0 +1,4 @@
+terraform {
+  backend "inmem" {
+  }
+}

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

@@ -0,0 +1,5 @@
+terraform {
+  backend "local" {
+    path = "foo.tfstate"
+  }
+}