diff --git a/internal/states/instance_object.go b/internal/states/instance_object.go index 85ca52878..7452b4174 100644 --- a/internal/states/instance_object.go +++ b/internal/states/instance_object.go @@ -1,6 +1,8 @@ package states import ( + "sort" + "github.com/zclconf/go-cty/cty" ctyjson "github.com/zclconf/go-cty/cty/json" @@ -108,6 +110,13 @@ func (o *ResourceInstanceObject) Encode(ty cty.Type, schemaVersion uint64) (*Res return nil, err } + // Dependencies are collected and merged in an unordered format (using map + // keys as a set), then later changed to a slice (in random ordering) to be + // stored in state as an array. To avoid pointless thrashing of state in + // refresh-only runs, we can either override comparison of dependency lists + // (more desirable, but tricky for Reasons) or just sort when encoding. + sort.Slice(o.Dependencies, func(i, j int) bool { return o.Dependencies[i].String() < o.Dependencies[j].String() }) + return &ResourceInstanceObjectSrc{ SchemaVersion: schemaVersion, AttrsJSON: src, diff --git a/internal/states/instance_object_test.go b/internal/states/instance_object_test.go new file mode 100644 index 000000000..8f961330d --- /dev/null +++ b/internal/states/instance_object_test.go @@ -0,0 +1,50 @@ +package states + +import ( + "testing" + + "github.com/google/go-cmp/cmp" + "github.com/hashicorp/terraform/internal/addrs" + "github.com/zclconf/go-cty/cty" +) + +func TestResourceInstanceObject_encode(t *testing.T) { + value := cty.ObjectVal(map[string]cty.Value{ + "foo": cty.True, + }) + // The in-memory order of resource dependencies is random, since they're an + // unordered set. + depsOne := []addrs.ConfigResource{ + addrs.RootModule.Resource(addrs.ManagedResourceMode, "test", "honk"), + addrs.RootModule.Child("child").Resource(addrs.ManagedResourceMode, "test", "flub"), + addrs.RootModule.Resource(addrs.ManagedResourceMode, "test", "boop"), + } + depsTwo := []addrs.ConfigResource{ + addrs.RootModule.Child("child").Resource(addrs.ManagedResourceMode, "test", "flub"), + addrs.RootModule.Resource(addrs.ManagedResourceMode, "test", "boop"), + addrs.RootModule.Resource(addrs.ManagedResourceMode, "test", "honk"), + } + rioOne := &ResourceInstanceObject{ + Value: value, + Status: ObjectPlanned, + Dependencies: depsOne, + } + rioTwo := &ResourceInstanceObject{ + Value: value, + Status: ObjectPlanned, + Dependencies: depsTwo, + } + riosOne, err := rioOne.Encode(value.Type(), 0) + if err != nil { + t.Fatalf("unexpected error: %s", err) + } + riosTwo, err := rioTwo.Encode(value.Type(), 0) + if err != nil { + t.Fatalf("unexpected error: %s", err) + } + // However, identical sets of dependencies should always be written to state + // in an identical order, so we don't do meaningless state updates on refresh. + if diff := cmp.Diff(riosOne.Dependencies, riosTwo.Dependencies); diff != "" { + t.Errorf("identical dependencies got encoded in different orders:\n%s", diff) + } +}