fix: support ephemeral resources in jsonchecks

.changes/v1.15/BUG FIXES-20251112-033830.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: 'cli: Fixed crash in `terraform show -json` when plan contains ephemeral resources with preconditions or postconditions'
+time: 2025-11-12T03:38:30.000000-08:00
+custom:
+    Issue: "37834"

internal/command/jsonchecks/checks_test.go

@@ -41,6 +41,16 @@ func TestMarshalCheckStates(t *testing.T) {
 	outputBInstAddr := addrs.Checkable(addrs.OutputValue{Name: "b"}.Absolute(moduleChildAddr))
 	checkBlockAAddr := addrs.ConfigCheckable(addrs.Check{Name: "a"}.InModule(addrs.RootModule))
 	checkBlockAInstAddr := addrs.Checkable(addrs.Check{Name: "a"}.Absolute(addrs.RootModuleInstance))
+	ephemeralResourceAddr := addrs.ConfigCheckable(addrs.Resource{
+		Mode: addrs.EphemeralResourceMode,
+		Type: "test",
+		Name: "ephemeral",
+	}.InModule(addrs.RootModule))
+	ephemeralResourceInstAddr := addrs.Checkable(addrs.Resource{
+		Mode: addrs.EphemeralResourceMode,
+		Type: "test",
+		Name: "ephemeral",
+	}.Instance(addrs.NoKey).Absolute(addrs.RootModuleInstance))
 
 	tests := map[string]struct {
 		Input *states.CheckResults
@@ -223,6 +233,48 @@ func TestMarshalCheckStates(t *testing.T) {
 				},
 			},
 		},
+		"ephemeral_resource": {
+			&states.CheckResults{
+				ConfigResults: addrs.MakeMap(
+					addrs.MakeMapElem(ephemeralResourceAddr, &states.CheckResultAggregate{
+						Status: checks.StatusFail,
+						ObjectResults: addrs.MakeMap(
+							addrs.MakeMapElem(ephemeralResourceInstAddr, &states.CheckResultObject{
+								Status: checks.StatusFail,
+								FailureMessages: []string{
+									"Ephemeral resource check failed.",
+								},
+							}),
+						),
+					}),
+				),
+			},
+			[]any{
+				map[string]any{
+					"address": map[string]any{
+						"kind":       "resource",
+						"mode":       "ephemeral",
+						"name":       "ephemeral",
+						"to_display": "ephemeral.test.ephemeral",
+						"type":       "test",
+					},
+					"instances": []any{
+						map[string]any{
+							"address": map[string]any{
+								"to_display": "ephemeral.test.ephemeral",
+							},
+							"problems": []any{
+								map[string]any{
+									"message": "Ephemeral resource check failed.",
+								},
+							},
+							"status": "fail",
+						},
+					},
+					"status": "fail",
+				},
+			},
+		},
 	}
 
 	for name, test := range tests {

internal/command/jsonchecks/objects.go

@@ -29,6 +29,8 @@ func makeStaticObjectAddr(addr addrs.ConfigCheckable) staticObjectAddr {
 			ret["mode"] = "managed"
 		case addrs.DataResourceMode:
 			ret["mode"] = "data"
+		case addrs.EphemeralResourceMode:
+			ret["mode"] = "ephemeral"
 		default:
 			panic(fmt.Sprintf("unsupported resource mode %#v", addr.Resource.Mode))
 		}