Add failing test case for tuple

command/format/diff_test.go

@@ -376,6 +376,41 @@ func TestResourceChange_JSON(t *testing.T) {
             }
         )
     }
+`,
+		},
+		"in-place update (tuple of different types)": {
+			Action: plans.Update,
+			Mode:   addrs.ManagedResourceMode,
+			Before: cty.ObjectVal(map[string]cty.Value{
+				"id":         cty.StringVal("i-02ae66f368e8518a9"),
+				"json_field": cty.StringVal(`{"aaa": [42, {"foo":"bar"}, "value"]}`),
+			}),
+			After: cty.ObjectVal(map[string]cty.Value{
+				"id":         cty.UnknownVal(cty.String),
+				"json_field": cty.StringVal(`{"aaa": [42, {"foo":"baz"}, "value"]}`),
+			}),
+			Schema: &configschema.Block{
+				Attributes: map[string]*configschema.Attribute{
+					"id":         {Type: cty.String, Optional: true, Computed: true},
+					"json_field": {Type: cty.String, Optional: true},
+				},
+			},
+			RequiredReplace: cty.NewPathSet(),
+			ExpectedOutput: `  # test_instance.example will be updated in-place
+  ~ resource "test_instance" "example" {
+      ~ id         = "i-02ae66f368e8518a9" -> (known after apply)
+      ~ json_field = jsonencode(
+          ~ {
+              ~ aaa = [
+                    42,
+                  ~ {
+                      ~ foo = "bar" -> "baz"
+                    },
+                    "value",
+                ]
+            }
+        )
+    }
 `,
 		},
 		"force-new update": {
@@ -730,7 +765,6 @@ func TestResourceChange_JSON(t *testing.T) {
     }
 `,
 		},
-		// TODO: JSON with unknown values inside
 	}
 	runTestCases(t, testCases)
 }