fix: Make state show command exit with code 1 if the stored state cannot be marshalled for rendering (#37933)

Prior to this change, when running a `state show` command with an address for a resource that existed in state but didn't match the current schema of the resource, users would see the "Failed to marshal" error but would also see output saying "The state file is empty. No resources are represented". This is misleading, as the state file isn't empty. Also, the command would exit with code 0 despite the error.

Author: SarahFrench

.changes/v1.15/BUG FIXES-20251121-183045.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: '`state show`: The `state show` command will now explicitly fail and return code 1 when it fails to render the named resources state'
+time: 2025-11-21T18:30:45.571448Z
+custom:
+    Issue: "37933"

internal/command/state_show.go

@@ -149,6 +149,7 @@ func (c *StateShowCommand) Run(args []string) int {
 	root, outputs, err := jsonstate.MarshalForRenderer(statefile.New(singleInstance, "", 0), schemas)
 	if err != nil {
 		c.Streams.Eprintf("Failed to marshal state to json: %s", err)
+		return 1
 	}
 
 	jstate := jsonformat.State{

internal/command/state_show_test.go

@@ -76,6 +76,69 @@ func TestStateShow(t *testing.T) {
 	}
 }
 
+func TestStateShow_errorMarshallingState(t *testing.T) {
+	state := states.BuildState(func(s *states.SyncState) {
+		s.SetResourceInstanceCurrent(
+			addrs.Resource{
+				Mode: addrs.ManagedResourceMode,
+				Type: "test_instance",
+				Name: "foo_invalid",
+			}.Instance(addrs.NoKey).Absolute(addrs.RootModuleInstance),
+			&states.ResourceInstanceObjectSrc{
+				// The error is caused by the state containing attributes that don't
+				// match the schema for the resource.
+				AttrsJSON: []byte(`{"non_existent_attr":"I'm gonna cause an error!"}`),
+				Status:    states.ObjectReady,
+			},
+			addrs.AbsProviderConfig{
+				Provider: addrs.NewDefaultProvider("test"),
+				Module:   addrs.RootModule,
+			},
+		)
+	})
+	statePath := testStateFile(t, state)
+
+	p := testProvider()
+	p.GetProviderSchemaResponse = &providers.GetProviderSchemaResponse{
+		ResourceTypes: map[string]providers.Schema{
+			"test_instance": {
+				Body: &configschema.Block{
+					Attributes: map[string]*configschema.Attribute{
+						"id":  {Type: cty.String, Optional: true, Computed: true},
+						"foo": {Type: cty.String, Optional: true},
+						"bar": {Type: cty.String, Optional: true},
+					},
+				},
+			},
+		},
+	}
+
+	streams, done := terminal.StreamsForTesting(t)
+	c := &StateShowCommand{
+		Meta: Meta{
+			testingOverrides: metaOverridesForProvider(p),
+			Streams:          streams,
+		},
+	}
+
+	args := []string{
+		"-state", statePath,
+		"test_instance.foo_invalid",
+	}
+	code := c.Run(args)
+	output := done(t)
+	if code != 1 {
+		t.Fatalf("unexpected code: %d\n\n%s", code, output.Stdout())
+	}
+
+	// Test that error outputs were displayed
+	expected := "unsupported attribute \"non_existent_attr\""
+	actual := output.Stderr()
+	if !strings.Contains(actual, expected) {
+		t.Fatalf("Expected stderr output to include:\n%q\n\n Instead got:\n%q", expected, actual)
+	}
+}
+
 func TestStateShow_multi(t *testing.T) {
 	submod, _ := addrs.ParseModuleInstanceStr("module.sub")
 	state := states.BuildState(func(s *states.SyncState) {